LNF 2009 Report...In 2009, avian abundance and richness indices showed a decline at treated sites for the ... Cabin Mastication CBMA 11 Hat Creek Plantation/Mastication yes 2006 Carter

Avian Monitoring in the Lassen National Forest

2009 Report

April 2010 Ryan D. Burnett, Diana Humple, Alissa Fogg, and Tim Guida

PRBO Conservation Science

Sierra Nevada Program PO BOX 634

Chester, CA 96020 PRBO Contribution #1740

Executive Summary .................................................................................................................. 1 Chapter 1. Landbird Monitoring of Fuel Treatments on the Lassen National Forest ................... 2

Background and Introduction ................................................................................................. 3 Methods ...................................................................................................................................... 4 Results ...................................................................................................................................... 12 Discussion................................................................................................................................. 18 Acknowledgements ................................................................................................................. 20 Literature Cited ...................................................................................................................... 21

Chapter 2. Resident and Neotropical Migratory Bird Response to Aspen Enhancement on the Lassen National Forest ................................................................................................................. 24

Background and Introduction ............................................................................................... 25 Project Area ............................................................................................................................. 25 Methods .................................................................................................................................... 26 Results ...................................................................................................................................... 31 Discussion................................................................................................................................. 41 Conclusions .............................................................................................................................. 45 Acknowledgements ................................................................................................................. 45 Literature Cited ...................................................................................................................... 46

Chapter 3. Resident and Neotropical Migratory Bird Monitoring in Mountain Meadows: 2009 Report ........................................................................................................................................... 48

Background and Introduction ............................................................................................... 49 Methods .................................................................................................................................... 50 Results ...................................................................................................................................... 54 Discussion................................................................................................................................. 62 Conclusions .............................................................................................................................. 65 Acknowledgements ................................................................................................................. 65 Literature Cited ...................................................................................................................... 66

1

Executive Summary PRBO Conservation Science (PRBO) has been conducting songbird monitoring in the

Northern Sierra since 1997. In this report we present results from avian monitoring of fuel

treatments and aspen restoration on the Lassen National Forest and from meadows across the

Northern Sierra with updated information from 2009.

Chapter one reports on the first year of our expanded avian monitoring of Herger

Feinstein Quincy Library Group Forest Recovery Act fuel treatments on the Lassen National

Forest. Recently treated sites across the forest were added in 2009 to compliment ongoing work

on the Forest as well as in the Plumas-Lassen study area. Preliminary results suggest the range of

treatments (DFPZ, Group Selection, mastication, fire) have varying effects on the avian

community.

The second chapter discusses results from our sixth year of monitoring landbirds in aspen

habitat on the Lassen National Forest. Results show that treated aspen stands support greater

total abundance of birds and abundance of key species such as Mountain Bluebird, Chipping

Sparrow, and Red-breasted Sapsucker but these initial benefits may be short-lived for some

species. In 2009, avian abundance and richness indices showed a decline at treated sites for the

second consecutive year.

In the third chapter we present results from monitoring of meadows across the Northern

Sierra Nevada, primarily within the Feather River watershed. We compared avian community

indices across sites and where applicable compared treated areas to adjacent reference sites.

Results suggest some Feather River watershed meadows still support diverse and abundant bird

populations including several species of conservation concern. However, a number of sites have

suppressed avian communities - likely a result of over a century of inappropriate management.

Management actions that restore hydrologic and ecological function and minimize the negative

impacts created through past management actions will likely benefit a number of avian species

including several that are of conservation concern.

2

Chapter 1. Landbird Monitoring of Fuel Treatments on the Lassen National Forest

Diana Humple, Tim Guida, and Ryan D. Burnett PRBO Conservation Science

Ch. 1. Fuel Treatments PRBO Avian Monitoring in the Lassen National Forest – 2009

3

Background and Introduction The Records of Decisions for the Sierra Nevada Forest Plan Amendment and

Herger Feinstein Quincy Library Group (HFQLG) Forest Recovery Act direct the Forest Service

to maintain and restore old forest conditions that provide habitat for a number of plant and

animal species (HFQLG 1999, SNFPA 2001, 2004). Simultaneously, they direct the Forest

Service to take steps to reduce risks of large and severe fire by removing vegetation and reducing

fuel loads in overstocked forests. Striking a balanced approach to achieving these potentially

competing goals is a significant challenge to effectively accomplish the various desired outcomes

of forest management.

Historically, fire was the primary force responsible for creating and maintaining habitat

diversity and landscape heterogeneity in the Sierra Nevada (Skinner and Chang 1996). Over the

past century, fire return intervals have been lengthened and the area affected by wildfire annually

has been dramatically reduced in the interior mountains of California (Taylor 2000, Taylor and

Skinner 2003, Stephens et al. 2007). Thus, there is little doubt fires role in influencing the

composition of the Sierra Nevada landscape has been reduced (Skinner and Chang 1996).

Fire suppression in concert with past silvicultural practices has resulted in increased stand

densities, loss of landscape heterogeneity, and increased fuel loads in Sierra Nevada Forests

(Vankat and Major 1978, Parsons and DeBenedetti 1979, McKelvey and Johnston 1992,

Minnich et al. 1995, Taylor and Skinner 2003). While the ways in which these changes affect

fire patterns and vegetation dynamics are frequently discussed, they also undoubtedly impact the

wildlife species that inhabit these forests.

Mechanical silvicultural treatments have the potential to fill some of fire’s historic

role in maintaining disturbance-dependent habitats (Weatherspoon 1996, Arno and Fiedler

2005). There has been considerable study of silvicultural treatments and their effects on

landbirds in eastern North American forests (Anand and Thompson 1997, King et al. 2001, Fink

et al. 2006, Askins et al. 2007) and the Cascades (Hansen et al. 1995, Hagar et al. 2004,

Chambers et al. 2007), but little published information exists on the effects of mechanical fuel

treatments on the avian community in the Sierra Nevada (but see Siegel and DeSante 2003 and

Garrison et al. 2005).

By monitoring the populations of a suite of landbird species we can measure the

effectiveness of management actions in achieving a sustainable and ecologically functional forest


4

ecosystem. Specifically, we are interested in determining the responses of landbirds to

management practices intended to produce forests with larger trees and high canopy cover along

with more open-canopy, smaller size class forest with reduced ladder and ground fuels.

In this report we summarize our efforts in 2009 intended to investigate landbird response

to changes in vegetation structure and composition that occur when forests are managed to

reduce fuels under the Herger Feinstein Quincy Library Group Forest Recovery Act Pilot Project

(HFQLG 1999). We summarize what surveys were completed in 2009, the treatment history at

each site, and some preliminary analysis of bird community indices by treatment type. We

compared community indices and most abundant species among treatment types and between

paired treated and reference sites. Future analyses will be more comprehensive, combining data

with those from the larger HFQLG region in which PRBO is collecting bird data (e.g., Plumas

National Forest). Future analysis will also include analysis of the longer-term effects of fuel

treatments on the avian community.

Methods

Study Location The study occurred in the Lassen National Forest within the boundaries of the HFQLG

Forest Recovery Act Pilot Project with the exception of the Wiley Ranch sites. The study sites

encompassed portions of Butte, Lassen, Plumas, Shasta and Siskiyou (Wiley Ranch) Counties at

the intersection of the Sierra Nevada and Cascade mountains of Northeastern California, USA

(Figure 1). Survey sites ranged in elevation from 1362 to 2074m with a mean elevation 1628m.

All sites occurred within the mixed conifer, true fir, and yellow pine zones though the actual

habitat structure and dominant tree species varied by site. A total of 519 point count stations

across 49 transects was surveyed in 2009 (Figure 1 and Table 1).


5

Figure 1. Location of of PRBO’s fuel treatment avian monitoring study sites in the Lassen National Forest. Black dots are point count stations and the Lassen National Forest is the area in green. Note, Brown’s Ravine study area includes Lower, Middle and Upper Oak Reference transects. Wiley Ranch is located approximately 20km north of the map on the Shasta Trinity National Forest but is administered by the Lassen National Forest.


6

Table 1. Fuel treatment point count transects, Lassen National Forest 2009. Summary of transect, number of points per transect, treatment type and details, if treatment has occurred, and year of treatment.

Transect Code # Points Ranger District Treatment Type Treated Year Treated Battle BATL 13 Almanor DFPZ yes 2004 Bizz DFPZ BIZD 7 Eagle Lake DFPZ yes 2005 Bizz Reference BIZR 7 Eagle Lake Reference n/a Black's Ridge DFPZ BRDZ 12 Hat Creek DFPZ yes 2004 Black's Ridge Group Selection BRGS 12 Hat Creek Group Selection yes 2008 Cabin Mastication CBMA 11 Hat Creek Plantation/Mastication yes 2006 Carter Meadow Road CMRO 12 Almanor Wildfire n/a (2008) Gray's Peak Central GPCE 10 Almanor Plantation/Mastication no Gray's Peak East GPEA 14 Almanor Plantation/Mastication no Gray's Peak West GPWE 13 Almanor Plantation/Mastication no Hog DFPZ HOGD 7 Eagle Lake DFPZ yes 2004 Hog Reference HOGR 7 Eagle Lake Reference n/a Harvey Valley DFPZ HVD 7 Eagle Lake DFPZ no Harvey Valley Reference HVR 7 Eagle Lake Reference n/a Jonesville DFPZ JVDZ 12 Almanor DFPZ yes 2005/2006/2007Konos DFPZ KOND 7 Eagle Lake DFPZ yes 2007 Konos Reference KONR 7 Eagle Lake Reference n/a Lower Oak Reference LOKR 32 Almanor Reference n/a Middle Oak Reference MOKR 6 Almanor Reference n/a North Cobble DFPZ NCDZ 12 Hat Creek DFPZ/Group Selection yes 2006 North Cobble Mastication NCMA 12 Hat Creek Plantation/Mastication yes 2007 Brown’s Ravine Oak Stand 1 OAK1 7 Almanor DFPZ yes 2005 Brown’s Ravine Oak Stand 2 OAK2 14 Almanor DFPZ yes 2005 Brown’s Ravine Oak Stand 3 OAK3 10 Almanor DFPZ yes 2005 Brown’s Ravine Oak Stand 4 OAK4 14 Almanor DFPZ yes 2006/2007 Brown’s Ravine Oak Stand 5 OAK5 7 Almanor DFPZ yes 2006/2007 Brown’s Ravine Oak Stand 6 OAK6 6 Almanor DFPZ no Brown’s Ravine Oak Stand 7 OAK7 8 Almanor DFPZ no Brown’s Ravine Oak Stand 8 OAK8 7 Almanor DFPZ no Brown’s Ravine Oak Stand 9 OAK9 6 Almanor DFPZ yes 2006/2007 Peg DFPZ PEGD 7 Eagle Lake DFPZ no


7

Transect Code # Points Ranger District Treatment Type Treated Year Treated Peg Reference PEGR 7 Eagle Lake Reference n/a Pittville North DFPZ PNDZ 12 Hat Creek Group Selection/Prescribed Fire yes 2005/2008 Pittville South DFPZ PSDZ 12 Hat Creek DFPZ/Group Selection yes 2005 Round DFPZ RNDD 8 Eagle Lake DFPZ yes 2005 Round Reference RNDR 7 Eagle Lake Reference n/a Storrie Fire Mastication East STME 10 Almanor Plantation/Mastication no fall 2009 Storrie Fire Mastication West STMW 11 Almanor Plantation/Mastication no Stover STVR 12 Almanor Plantation/Mastication yes 2007 Upper Oak Reference UOKR 36 Almanor Reference n/a Warner Burn WABU 12 Almanor Prescribed Fire yes 2006 Warner DFPZ WADZ 12 Almanor DFPZ yes 2006/2007 Wiley Ranch North WRNO 16 Hat Creek DFPZ no Wiley Ranch South WRSO 16 Hat Creek DFPZ no West Shore North DFPZ WSND 8 Almanor DFPZ yes 2002/2004 West Shore North Reference WSNR 6 Almanor Reference n/a West Shore South DFPZ WSSD 9 Almanor DFPZ yes 2002/2004 West Shore South Reference WSSR 4 Almanor Reference n/a Young Pine YOPI 8 Almanor Plantation/Mastication no TOTAL 519


8

Site Selection and Treatment History

We combined data across multiple projects on the Almanor, Eagle Lake, and Hat

Creek Ranger Districts of the Lassen National Forest (Table 1) to investigate the effects

of HFQLG treatments on landbirds. Treatments included Defensible Fuel Profile Zones

(DFPZ), Group Selection, Plantation/Mastication, and fire (prescribed and wild) (Table

2). Treatments, and specific treatment histories at given transects and point count

stations, are summarized in Table 1.

Table 2. Forest treatment types in the Northern Sierra Nevada for which the response of landbirds was investigated in 2009.

Treatment Description Defensible Fuel Profile Zones (DFPZ)

Mechanically created shaded fuel break, generally linear in shape; affects more acres than any treatments in our study area.

Group Selection Removal of all overstory trees in 0.5 – 2 acre area, sometimes embedded within a DFPZ network.

Plantation/Mastication Plantings of Ponderosa Pine. Mechanical shredding of shrubs that sometimes uproots shrubs but often leaves plants alive below ground to regenerate.

Burn Generally low intensity human ignited burning. Generally consumes understory fuels and some middle story trees. Some sites experienced wildfire or backfires set during a wildfire.

DFPZ treatments monitored on the Eagle Lake Ranger District were established

in 2004 after consulting ranger district staff and available GIS layers. We selected 6 sites

that were slated for treatment in the next several years. At each treatment area we

established between 5 to 7 point counts inside of treatment boundaries and 5 to 8 sites in

similar habitat at least 100m outside the treatment but within 500m of the treated area

(see Burnett et al. 2004).

A similar protocol was used for the Brown’s Ravine Black Oak enhancement

DFPZ project in the Almanor Ranger District of the Lassen (Table 1). In this project,

treatment units were larger so we filled each unit with points spaced 220m apart. Each

unit contained between 5 and 14 points. Reference sites were established in adjacent units

where no treatment was planned (Burnett et al. 2004).

In 2009, 21 new transects comprising 261 point-count stations were added to the

project (Table 1) in the Almanor and Hat Creek Ranger Districts. We had already

established six transects in DFPZ’s on the Eagle Lake rangers district in 2004, of which

five had already been treated so we did not add additional sites in that district in 2009.

We used GIS layers of the boundaries of fuel projects that had already been implemented


9

to select new monitoring sites in the Almanor and Hat Creek ranger districts. We chose

projects that had been completed in the past five years and were large enough to contain a

minimum of 8 point count stations spaced 250m apart. We also selected projects in order

to obtain a sample of each of the four treatment types described in Table 2 above. In

addition to the previously treated fuel treatment sites, we also established transects within

the proposed Gray’s Peak project area and Storrie Fire mastication units on the ARD. We

used a similar site selection protocol as described above where GIS layers of unit

boundaries were employed to establish points in a way that would maximize the points a

person could sample in one morning while covering the majority of treatment units in the

project. Additionally three plantation study sites where we had already established

monitoring in previous years – Young Pine II, Carter Meadow Road, and Stover (Young

Pine I) – are included in this analysis and there site selection was very similar to that

already described above. For all of these sites we had no prior knowledge of the site

conditions prior to establishing the points. With the exception of the West Shore North

and South DFPZ’s, we did not establish adjacent reference points for any of these new

transects.

For each point count station, we identified the treatment history with respect to

four distinct treatment types (Tables 1 & 2). A given treatment was only considered to

occur at a point if the point fell inside the treatment polygon. Of the 519 points, 277 had

been treated in one or more ways prior to the 2009 point count seasons; the remaining

points were considered a combination of sites that have not yet been treated (but will be)

or were reference sites paired with treated units (Table 3).

Table 3. The number of point count stations by treatment type in each ranger district in PRBO’s Northern Sierra study area in 2009. Each point was visited twice in 2009.

Treatment Type Almanor Eagle Lake

Hat Creek

Total Number of points 319 85 115 DFPZ Number of points 133 43 58 Number of post-treatment points 108 29 26Group Selection Number of points 0 0 27 Number of post-treatment point visits n/a n/a 27Mastication Number of points 78 0 23 Number of post-treatment point visits 121 n/a 23Burn Number of points 24 0 7 Number of post-treatment point visits 242 n/a 7Reference Number of reference points 84 42 0 121 points were treated fall 2009 (after point count surveys complete, 212 prescribed burn, 12 wildfire (backfire)


10

Survey Protocol

We used a standardized five-minute variable circular plot point count census

(Reynolds 1980, Ralph et al. 1993, Ralph et al. 1995) to sample the avian community in

the study area. In this method, points are clustered in transects, but data were only

collected from fixed stations, not along the entire transect.

In 2009, all birds detected at each station during the five-minute survey were

recorded according to their initial distance from the observer. Detections were recorded

to the nearest meter up to 300 meters. Beyond 300 meters observations were recorded

simply as greater than 300 meters. The method of initial detection (song, visual, or call)

for each individual was also recorded. All observers underwent intensive 14 day training

in bird identification and distance estimation prior to conducting surveys. Laser

rangefinders were used to assist in distance estimation at every survey point.

Counts began around local sunrise, were completed within four hours, and did not

occur in inclement weather. Each transect was visited twice during the peak of the

breeding season from mid-May through the first week of July (Table 4).

Table 4. Dates of point count visits, Lassen National Forest fuel treatment transects 2009.

code visit 1 visit2 BATL 6/1/2009 6/20/2009 BIZD 5/14/2009 6/21/2009 BIZR 5/14/2009 6/21/2009 BRDZ 6/9/2009 6/18/2009 BRGS 6/9/2009 6/18/2009 CBMA 6/12/2009 6/29/2009 CMRO 6/2/2009 6/24/2009 GPCE 5/30/2009 6/15/2009 GPEA 6/1/2009 6/15/2009 GPWE 5/30/2009 6/15/2009 HOGD 5/15/2009 6/21/2009 HOGR 5/15/2009 6/21/2009 HVD 5/25/2009 6/23/2009 HVR 5/25/2009 6/23/2009 JVDZ 6/1/2009 6/14/2009 KOND 5/16/2009 6/30/2009 KONR 5/16/2009 6/30/2009 LOKR 5/18/2009, 5/19/2009 6/16/2009, 6/17/2009, 6/18/2009 MOKR 5/23/2009 6/25/2009 NCDZ 6/3/2009 6/19/2009 NCMA 6/3/2009 6/19/2009 OAK1 5/18/2009, 5/19/2009 6/16/2009, 6/17/2009


11

code visit 1 visit2 OAK2 5/18/2009, 5/19/2009 6/16/2009, 6/17/2009 OAK3 5/18/2009 6/16/2009 OAK4 5/23/2009 6/25/2009 OAK5 5/23/2009 6/25/2009 OAK6 5/21/2009 6/26/2009 OAK7 5/21/2009, 5/22/2009 6/23/2009, 6/25/2009, 6/26/2009 OAK8 5/21/2009, 5/22/2009 6/23/2009, 6/25/2009 OAK9 5/19/2009 6/17/2009 PEGD 5/16/2009 6/11/2009 PEGR 5/16/2009 6/11/2009 PNDZ 6/10/2009 6/18/2009 PSDZ 6/3/2009 6/19/2009 RNDD 5/16/2009 6/11/2009 RNDR 5/16/2009 6/11/2009 STME 5/24/2009 6/20/2009 STMW 6/11/2009 6/30/2009 STVR 5/29/2009 6/24/2009 UOKR 5/21/2009, 5/22/2009 6/23/2009, 6/25/2009, 6/26/2009 WABU 6/2/2009 6/27/2009 WADZ 6/2/2009 6/27/2009 WRNO 6/12/2009 6/20/2009 WRSO 6/12/2009 6/20/2009 WSND 6/8/2009 6/29/2009 WSNR 6/8/2009 6/29/2009 WSSD 6/8/2009 6/24/2009 WSSR 6/8/2009 6/24/2009 YOPI 6/8/2009 6/24/2009

Statistical Analysis

Annual per-point species abundance, richness, and diversity metrics of birds

within 50 meters were summarized for 519 points. We excluded species that are not

adequately sampled using the point count method (e.g., waterfowl, shorebirds, kingfisher,

and raptors), as well as species not breeding in the region (e.g., Rufous Hummingbird).

We also excluded European Starling and Brown-headed Cowbird from analysis of

species richness and total bird abundance because they are invasive species regarded as

having a negative influence on the native bird community. Birds unidentified to species

(e.g., XXWA, Unidentified Warbler) were included in abundance estimates and, if the

only one of that taxa, in richness estimates, but were excluded from diversity indices.

We define species richness as the mean number of species detected within 50

meters of the observer per point across visits. The index of total bird abundance is the


12

mean number of individuals detected per point per visit; this number is obtained by

dividing the total number of detections within 50 meters by the number of stations and

the number of visits (2). Species diversity was measured using a modification of the

Shannon-Wiener index (Krebs 1989) introduced by MacArthur (1965), which reflects

combined species richness and equal distribution of the species. Diversity can be

considered as mean species diversity (average diversity per point). The relative

abundance of species is the mean number of detections of a given species per point per

visit within 50 meters of observers.

We determined community indices for each transect. We also compared

community indices (richness and abundance), as well as the abundance within 50 meters

of the ten most common species (at all study sites combined), among treatment types.

Means and confidence intervals were generated with StataIC 10.0 (StataCorp 2007). For

this, we lumped untreated sites with reference sites as “Untreated/Reference”. We

assigned points where group selection had occurred inside of another treatment simply as

group selection; we lumped prescribed burn and wildfire burned points under the

“treatment” category of “Fire”. The ten most abundant species were, in order: Mountain

Chickadee, Audubon’s Warbler, Dusky Flycatcher, Oregon Junco, Red-breasted

Nuthatch, Golden-crowned Kinglet, Hermit Warbler, Chipping Sparrow, Western

Tanager, and Fox Sparrow.

Additionally, we compared these indices for paired reference versus treated

transects using a two-tailed t-test, and included only sites that had been treated prior to

the 2009 breeding season; these included Biz, Hog, Konos, Round, West Shore North,

and West Shore South (DFPZ and Reference transects, respectively). Results Community Indices by Transect

Ninety-six species in total were detected across the 49 transects in 2009. Seventy-

nine were used in assessing community indices (17 species were removed because they

were not appropriate to assess via the point count method; see Methods above).

Community index values were highly variable among transects (Table 5).

Diversity values were as low as 0.99 (Wiley Ranch South, untreated DFPZ), with the

most diverse sites having diversity values as high as 7.53 (Carter Meadow Road, hand


13

conifer release in 2001 and burned in 2008 Cub fire), 7.63 (Battle, 5 years post DFPZ

treatment), and 8.70 (West Shore South Reference). Abundance values ranged from 0.59

birds per point (Wiley Ranch South) to 7.04 (Battle), 7.06 (West Shore South DFPZ,

treated in 2002 or 2004), and 7.25 (West Shore South Reference) birds per point. Species

richness values ranged from 1.00 (Wiley Ranch South) up to 8.54 (Battle), 8.58 (Carter

Meadow Road), and 9.5 (West Shore South Reference).

Table 5. Point count indices for fuel treatment transects, Lassen National Forest 2009.

Station Diversity

(sw) Abundance

(individuals/visit) Species richness

BATL 7.63 7.04 8.54 BIZD 3.78 2.71 4.00 BIZR 5.40 4.71 6.00 BRDZ 6.70 6.67 7.58 BRGS 3.08 2.00 3.17 CBMA 6.20 6.14 7.00 CMRO 7.53 6.71 8.58 GPCE 5.26 4.35 5.70 GPEA 4.91 4.82 5.57 GPWE 6.85 5.96 7.54 HOGD 3.36 2.57 3.71 HOGR 3.48 2.86 3.71 HVD 4.24 3.21 4.71 HVR 3.79 2.71 4.00 JVDZ 4.96 3.67 5.33 KOND 4.12 3.21 4.43 KONR 5.22 4.07 5.57 LOKR 5.88 4.80 6.38 MOKR 6.41 4.75 6.83 NCDZ 5.04 3.79 5.42 NCMA 3.42 3.17 3.83 OAK1 6.04 4.43 6.57 OAK2 6.75 5.36 7.29 OAK3 6.46 5.35 7.20 OAK4 5.86 4.25 6.29 OAK5 4.62 4.07 4.86 OAK6 5.84 4.17 6.17 OAK7 4.88 3.69 5.25 OAK8 4.97 3.93 5.29 OAK9 4.84 3.00 5.00 PEGD 3.94 3.57 4.43 PEGR 5.31 4.14 5.86 PNDZ 5.74 4.29 6.25 PSDZ 5.33 4.00 5.75 RNDD 2.48 2.00 2.63


14

Station Diversity

(sw) Abundance

(individuals/visit) Species richness

RNDR 4.17 3.07 4.43 STME 6.15 5.75 6.80 STMW 5.24 4.05 5.55 STVR 3.86 3.25 4.17 UOKR 6.20 4.93 6.75 WABU 7.31 4.88 7.67 WADZ 6.58 5.21 7.17 WRNO 2.88 1.88 3.00 WRSO 0.99 0.59 1.00 WSND 6.01 5.06 6.75 WSNR 5.16 3.83 5.50 WSSD 7.18 7.06 8.11 WSSR 8.70 7.25 9.50 YOPI 5.18 4.44 5.75 Community Indices between Treated and Untreated Paired Transects

Comparing indices of abundance and richness between paired transects, a general

pattern was observed of higher community indices at the reference sites than at the

treated DFPZ sites (Figures 2 and 3; Table 5). The mean total bird abundance per point

was significantly higher in the reference transect than the treated transect for BIZ (2.71

versus 4.71 birds/pt; t-statistic = -2.77, P = 0.02). The mean richness per point was

significantly higher in the reference transect than the treated transect for RND (2.63

versus 4.43 species/pt; t-statistic = -2.31, P = 0.04). Differences also approached

significant between treated and reference sites for Bizz, Konos and West Shore South

species richness and for Round total abundance; for all, they were again greater in the

reference site.

Table 5. Comparison between paired treated DFPZ versus reference transects, Lassen National

Forest 2009.

Index of Abundance Species Richness

DFPZ

Mean (SE) Ref

Mean (SE) Test

statisticP

Value DFPZ

Mean (SE) Ref

Mean (SE) Test

statistic P Value BIZ 2.71 (0.56) 4.71 (0.45) -2.77 0.02* 4.00 (0.87) 6.00 (0.58) -1.91 0.08 HOG 2.57 (0.52) 2.86 (0.5) -0.40 0.70 3.71 (0.36) 3.71 (0.68) 0 1.00 KON 3.21 (0.55) 4.07 (0.32) -1.34 0.20 4.43 (0.48) 5.57 (0.48) -1.68 0.12 RND 2.00 (0.37) 3.07 (0.48) -1.70 0.11 2.63 (0.33) 4.43 (0.72) -2.31 0.04* WSN 5.06 (0.67) 3.83 (0.75) 1.22 0.25 6.75 (0.75) 5.50 (1.18) 0.94 0.37 WSS 7.06 (0.44) 7.25 (0.72) -0.24 0.82 8.11 (0.39) 9.50 (0.65) -1.92 0.08

*significant at the P < 0.05 level


15

In a few cases (e.g., Hog richness and abundance and West Shore South

abundance), indices were similar between paired treated and reference transects.

Although the opposite pattern was observed for West Shore North, the results are not

significant as the confidence intervals overlap.

Figure 2. Index of abundance from paired DFPZ versus reference point count stations, Lassen National Forest 2009. Error bars represent 95% confidence intervals.

Community Indices and Species Abundance Among Treatment Types

Figures 3, 4 and 5 summarize community indices among treatment types. The

treatment type with the highest indices overall, and higher than any of the other treatment

types (P<0.05), was burn. DFPZ treatment points overall had the second highest indices;

diversity and richness there were higher (P<0.05) than any other treatment type except

burn. Group selection treatment sites had the lowest community indices.

0

2

4

6

8

10

12

BIZ HOG KON RND WSN WSS

Mean # birds pe

r visit (<50m

)

Total Abundance (DFPZ vs. Reference)

DFPZ

Ref


16

Figure 3. Mean per point richness values for paired DFPZ versus reference point count stations, Lassen National Forest 2009. Error bars represent 95% confidence intervals.

Figure 3. Species diversity (mean diversity per point per visit within 50m) for Lassen National Forest fuel treatment point counts 2009. Error bars represent 95% confidence intervals.

0

2

4

6

8

10

12

14

BIZ HOG KON RND WSN WSS

Mean # of spe

cies per point (<

50m)

Species Richness (DFPZ vs. Reference)

DFPZ

Ref

0.001.002.003.004.005.006.007.008.009.00

Burn

DFPZ

Group

Selectio

n

Plantatio

n/Mastication

Untreated

/Referen

ce

Mean bird diversity per point

Shannon Index of Diversity

BurnDFPZGroup SelectionPlantation/MasticationUntreated/Reference


17

Figure 4. Bird abundance (mean number of individual birds per point per visit within 50m) for Lassen National Forest fuel treatment point counts 2009. Error bars represent 95% confidence interval.

Figure 5. Species richness (mean number of species per point per visit within 50m) for Lassen National Forest fuel treatment point counts 2009. Error bars represent 95% confidence interval.

0.001.002.003.004.005.006.007.00

Burn

DFPZ

Group

Selectio

n

Plantatio

n/Mastication

Untreated

/Referen

ce

Mean birds pe

r po

int (< 50m

)

Total Bird Abundance


0.001.002.003.004.005.006.007.008.009.0010.00

Burn

DFPZ

Group

Selectio

n

Plantatio

n/Mastication

Untreated

/Referen

ce

Mean nu

mbe

r of spe

cies per point

Species Richness



18

Bird species more associated with trees and canopy (e.g., Mountain Chickadee,

Hermit Warbler, and Western Tanager), as well as those associated with open understory

(Oregon Junco) were most common at the treated DFPZ points. Species associated with a

shrub understory were most common in the burn treatment category. Table 6. Mean species abundance (and standard error) for top 10 most abundant species (detections <50m from observer) over the project area, by treatment type, Lassen National Forest 2009. Highest value of a given index across all treatment levels is shown in bold. Species are listed in taxonomic order.

Burn n=31

DFPZ n=184

Group Selection

n=27

Plantation/ Mastication

n=35

Untreated/Reference

n=242 Dusky Flycatcher 0.62 (0.12) 0.35 (0.04) 0.04 (0.03) 0.47 (0.09) 0.50 (0.04) Mountain Chickadee 0.35 (0.07) 0.58 (0.04) 0.28 (0.06) 0.57 (0.10) 0.38 (0.03) Red-breasted Nuthatch 0.24 (0.06) 0.24 (0.03) 0 (0) 0.17 (0.06) 0.25 (0.03) Golden-crowned Kinglet 0.24 (0.08) 0.19 (0.02) 0 (0) 0.14 (0.05) 0.24 (0.03) Audubon’s Warbler 0.16 (0.04) 0.51 (0.04) 0.20 (0.06) 0.54 (0.11) 0.41 (0.03) Hermit Warbler 0.16 (0.05) 0.27 (0.03) 0 (0) 0.11 (0.07) 0.17 (0.02) Western Tanager 0.19 (0.05) 0.26 (0.03) 0.07 (0.033) 0.17 (0.05) 0.13 (0.02) Chipping Sparrow 0.27 (0.11) 0.23 (0.04) 0.46 (0.09) 0.26 (0.08) 0.11 (0.02) Oregon Junco 0.32 (0.07) 0.48 (0.04) 0.37 (0.07) 0.21 (0.06) 0.31 (0.03) Fox Sparrow 0.45 (0.14) 0.02 (0.01) 0.02 (0.02) 0.13 (0.07) 0.25 (0.03)

Discussion In 2009, PRBO monitored 49 point count transects totaling 519 points as part of

our long-term landbird response to fuel treatments project. Such long-term monitoring is

allowing us to assess how fuel reduction treatments change the composition and

abundance of landbird species over space and time. Along with our Plumas-Lassen study

these two data sets provide us with the most comprehensive study of the response of

landbirds to fuel treatments anywhere in the Sierra Nevada.

Overall, we found that bird community indices were highest at burned sites,

consistent with findings from our Plumas-Lassen study (Burnett et al. 2009). Sites

selected for prescribed fire may be in areas with lower fuel loads which allow for the use

of prescribed fire. The other treatment type with relatively high indices overall were

DFPZ’s. As with fire, it will be important to tease out the effect of time since treatment in

order to truly understand the impacts of DFPZ management practices on landbirds but

our preliminary data and that from the Plumas-Lassen study suggest that the effects of

DFPZ treatments on landbirds are mixed both in terms of species response and site to site


19

differences. The pre-existing conditions at a site and the prescription of the DFPZ

treatment are both factors that likely contribute to the response of the avian community to

treatments. We continue to suggest that treatments that retain variable canopy cover and

target areas of lower overall avian diversity (e.g. overly dense 2nd growth white fir forest)

will likely have the greatest positive impact on the landbird community.

The treatment type with the lowest community indices overall was Group

Selection – a treatment that removes all of the overstory of trees in a 1- 2 acre area.

However, the fact that all Group Selection transects were in the Hat Creek Ranger

District may be biasing this result and as with DFPZ’s, the effects of group selections on

the avian community is likely heavily contingent on the pre-existing condition at the site

and landscape context of the treatment. For example, we did not find a significant effect

of group selections on avian diversity in denser west side forest on Plumas National

Forest (Burnett et al. 2009). This may be because our group selection sites often straddled

the edges of treatments since they were established prior to treatments and boundaries

were moved slightly. Whereas in the LNF we established points after treatments had been

implemented and thus were able to place our point count stations in the center of the

group selections and thus surveyed less edge. We would expect lower bird diversity

within group selections immediately following treatments as the vast majority of

vegetation structure has been removed however, few negative effects were found in

group selection treatments in pine-hardwood dominated stands in the central Sierra

Nevada (Garrison et al. 2005).

Of the top ten most abundant species, each treatment type could boast having the

highest abundance of at least one of the species across all five treatments. The two

treatments that had the greatest abundance of the largest number of species were, again,

DFPZ and burn. The species most common in burn varied in life history from species

associated with understory shrub habitat (Dusky Flycatcher, Fox Sparrow) to a species

associated with large trees (Golden-crowned Kinglet), reflecting the diversity in habitats

created after fires, especially when combining sites that burned in different years and

different intensities. The species most common in DFPZ were generalists (Mountain

Chickadee and Oregon Junco) or mature forest associated species (Hermit Warbler and

Western Tanager).


20

When we compared indices of abundance and richness between paired transects, a

general pattern was observed of significantly higher community indices at the reference

sites than at the treated DFPZ sites. Because this result differs from the higher indices

observed across all five treatment types at DFPZ than reference sites, when not restricted

to the paired sites, this underscores the usefulness of conducting studies with paired sites

when possible. This also suggests there maybe some at least short-term loss in habitat

quality for the landbird community at sites that have been converted to shaded fuel

breaks. In the northern Sierra Nevada, many species are associated with foliage volume

in the middle and especially understory (Verner and Larson 1989). It is this component

(fuel ladders) of the habitat that is often removed during DFPZ treatments (as well as in

group selection, pre-commercial thinning, and mastication) and could result in short-term

declines of a number of species following fuel reduction treatments. However, in group

selections and mastication understory, foliage volume is likely to return whereas in

shaded fuel breaks (>40% canopy cover retained) it may be less likely to return. It is for

these reasons that we suggest a mosaic design of varying canopy covers in fuel treatments

be prescribed.

Consistent with previous results, our preliminary data from the LNF fuel

treatments suggest that sites treated with low to moderate intensity fire – including

prescribed fire – harbor some of the highest landbird diversity in the Northern Sierra

Nevada. The use of low to moderate intensity fire should be greatly increased in these

forests.

We focused in this report on summarizing 2009 efforts and results, but intend in

the coming years to conduct more comprehensive analyses, both spatially and temporally.

We remain conservative about generalizing patterns thus far, as a more in depth analysis

will take into account time since treatment, pre versus post treatments, and spatial

patterns unrelated to treatment.

Acknowledgements Funding for this project was provided by the Lassen National Forest and Herger

Feinstein Quincy Library Group Forest Recovery Act monitoring funds. We especially

would like to thank Coye Burnett, Tom Frolli, Karen Harville, Bobette Jones, Tom

Rickman, and Mark Williams of the Lassen National Forest and Colin Dillingham – the


21

USFS QLG monitoring coordinator - for their support and assistance with this project.

We also wish to thank Tim Guida, crew leader, and Nathan Fronk and Luke Owens, our

2009 field crew.

Literature Cited Anand, E.M. and F.R. Thompson III. 1997. Forest bird response to regeneration practices

in central hardwood forests. The Journal of Wildlife Management 61, 159-171. Arno, S.F., and C.E. Fiedler. 2005. Mimicking Nature’s Fire: Restoring Fire Prone

Forests in the West. Island Press, Washington D.C. Askins, R.A., B Zuckerberg, and L. Novak. 2007. Do the size and landscape context of

forest openings influence the abundance of breeding success of shrubland songbirds in southern New England? Forest Ecology and Management 250, 137-147.

Burnett, R.D., D.Humple, T.Gardali, and M.Rogner. 2004. Avian Monitoring in the

Lassen National Forest. A PRBO report to the USFS. Contribution # 1242. Burnett, R.D., N.Nur, and C.A.Howell. In prep. Implications of spotted owl management

for landbirds in the Sierra Nevada, CA, USA. Forest Ecology and Management. Burnett, R.D., D. Jongsomjit, and D. Stralberg. 2009. Avian monitoring in the Plumas

and Lassen National Forest: 2008 Annual Report. PRBO report to the U.S. Forest Service. Contribution # 1684.

Chambers, C.L., W.C. McComb, and J.C. Tappeiner II. 1999. Breeding bird responses to

three silvicultural treatments in the Oregon Coast Range. Ecological Applications 9: 171-185.

ESRI 2000. Arc View GIS 3.2a. Environmental Systems Research Institute. Redlands,

CA. Fink, A.D., F.R. Thompson III, and A.A. Tudor. 2006. Songbird use of regenerating

forest, glade, and edge habitat types. Journal of Wildlife Management 70, 180-188.

Garrison, B.A., M.L. Triggs, and R.L. Wachs. 2005. Short-term effects of group-selection

timber harvest on landbirds in montane hardwood-conifer habitat in the central Sierra Nevada. Journal of Field Ornithology 76: 72-82.

Hagar, J., S. Howlin, and L.Ganio. 2004. Short-term response of songbirds to

experimental thinning of young Douglas-fir forests in the Oregon Cascades. Forest Ecology and Management 199: 333-347.


22

Hansen, A.J., W.C. McComb, R. Vega, M.G. Raphael, and M. Hunter. 1995. Bird habitat relationships in natural and managed forests in the west cascades of Oregon. Ecological Applications 5: 555-569.

HFQLG (Herger-Feinstein Quincy Library Group Forest Recovery Act) 1999. Final

Environmental Impact Statement, U.S. Department of Agriculture, Forest Service, Pacific Southwest Region, Vallejo, CA. http://www.fs.fed.us/r5/hfqlg/publications/1999_feis/TOC.htm

King, D.I., R.M. Degraaf, and C.R. Griffin. 2001. Productivity of early successional

shrubland birds in clearcuts and groupcuts in an eastern deciduous forest. Journal of Wildlife Management 65: 345-350.

Krebs, C.J. 1989. Ecological Methodology. Harper and Row Publishers, New York, New

York: 654 pp. MacArthur, R.H. 1965. Patterns of species diversity. Biological Reviews 40:510-533. Martin, T.E. and G.R. Geupel. 1993. Nest monitoring plots: Methods for locating nests

and monitoring success. J. Field Ornith. 64:507-519. McKelvey, K.S. and J.D. Johnston. 1992. Historical perspectives on forests of the Sierra

Nevada and the Transever Ranges of Southern California: Forest conditions at the turn of the century. Pp. 225-246 In The California spotted owl: a technical assessment of its current status. Tech Coordination by J. Verner, K.S. McKelvey, B.R. Noon, R.J. Gutierrez, G.I. Gould Jr., and T.W. Beck. Pacific Southwest Research Station General Technical Report 133. Albany, CA.

Minnich, R.A., M.G. Barbour, J.H. Burk, and R.F. Fernau. 1995. Sixty years of change in

California coniferous forests of the San Bernardino mountains. Conservation Biology 9:902-914.

Parsons, D.J. and S.H. Benedetti. 1979. Impact of fire suppression on a mixed-conifer forest. Forest Ecology and Management 2: 21-33. Ralph, C.J., G.R. Geupel, P. Pyle, T.E. Martin, and D.F. DeSante 1993. Field Methods

for Monitoring Landbirds. U.S. Department of Agriculture, Forest Service, General Technical Report PSW-144.

Ralph, C.J., S. Droege, and J.R. Sauer. 1995. Managing and monitoring birds using point

counts: standards and applications. In C. J. Ralph, J. R. Sauer and S. Droege (eds.), Monitoring Bird Populations by Point Counts. USDA Forest Service Publication, Gen. Tech. Rep. PSW-GTR-149, Albany, CA .

Reynolds, R.T., J.M. Scott, and R.A. Nussbaum. 1980. A variable circular plot method

for estimating bird numbers. Condor 82:309:313.


23

Siegel, R.B. and D.F. DeSante. 2003. Bird communities in thinned versus unthinned sierran mixed conifer stands. Wilson Bulletin 115: 155-165.

Skinner, C.N. and C.Chang. 1996. Fire regimes, past and present. Sierra Nevada

Ecosystem Project: Final Report to Congress. Vol. 2, Assessments and scientific basis for management options, pp. 1041-1069. University of California Centers for Water and Wildland Resources, Davis, CA, USA.

SNFPA 2001. Sierra Nevada Forest Plan Amendment Final Environmental Impact

Statement, Record of Decision. United States Department of Agriculture, Forest Service, Pacific Southwest Region, Vallejo, CA. http://www.fs.fed.us/r5/snfpa/library/archives/rod/rod.pdf

SNFPA 2004. Sierra Nevada Forest Plan Amendment, Final Supplemental

Environmental Impact Statement, Record of Decision. United States Department of Agriculture, Forest Service, Pacific Southwest Region, Vallejo, CA. http://www.fs.fed.us/r5/snfpa/final-seis/rod/

Stata Corp. 2007. Intercooled Stata 10 for Windows. Stata Corp. LP College Station,

TX. Stephens, R.E. Martin, and N.E. Clinton. 2007. Prehistoric fire area and emissions from

California forests, woodlands, shrublands, and grasslands. Forest Ecology and Management 251: 205-216.

Taylor, A.H. 2000. Fire regimes and forest changes along a montane forest gradient, Lassen Volcanic National Park, southern Cascade Mountains, USA. Journal of Biogeography 27:87-104. Taylor, A.H. & C.N. Skinner. 2003. Spatial patterns and controls on historical fire

regimes and forest structure in the Klamath Mountains. Ecological Applications 13:704-719.

Vankat, J.L. and J. Majors 1978. Vegetation changes in Sequoia National Park,

California. Journal of Biogeography 5:377-402. Weatherspoon, C.P. 1996. Fire-silvicultural relationships in Sierra forests. In Sierra

Nevada Ecosystem Project Final Report to Congress, Vol. 2: Assessments and Scientific Basis for Management Options. Centers for Water and Wildland Resources, University of California, Davis, pp. 1167-1176.

24

Chapter 2. Resident and Neotropical Migratory Bird Response to Aspen Enhancement on the Lassen National Forest

Photo by Kevin Cole

Ryan D. Burnett & Alissa Fogg PRBO Conservation Science

Chapter 2. Aspen Enhancement PRBO Avian Monitoring in the Lassen National Forests - 2009

25

Background and Introduction

In the Sierra Nevada, with extensive livestock grazing and the absence of regular

fire, aspen are often out-competed by conifers (Mueggler 1985). As a result, the health of

aspen has deteriorated and its extent throughout western North America has been reduced

as much as 96% (Bartos and Campbell 2001). Aspen inventories and assessments on the

Lassen National Forest found the vast majority of aspen stands to be in poor health and in

need of management actions to avoid further degradation or complete stand loss. As a

result, the forest has implemented strategies to restore aspen habitat by removing

competing conifers and excluding livestock grazing (Jones et al. 2005).

Aspen habitat in western North America can support a disproportionately rich and

abundant avian community compared to the surrounding habitats (Flack 1976, Winternitz

1980, Mills et al. 2000, Griffis-Kyle and Beier 2003). Several bird species demonstrate a

strong affinity with aspen, including Northern Goshawk (Accipiter gentilis), Red-naped

and Red-breasted Sapsuckers (Sphyrapicus nuchalis/ruber), Dusky Flycatcher

(Empidonax oberholseri), Warbling Vireo (Vireo gilvus), Swainson’s Thrush (Catharus

ustulatus), and MacGillivray’s Warbler (Oporornis tolmiei) (Salt 1957, Flack 1976,

Finch and Reynolds 1988, Heath and Ballard 2003, Richardson and Heath 2004).

In 2004, PRBO began an adaptive management based project monitoring birds

across aspen habitat on the Eagle Lake and Almanor Ranger Districts of the Lassen

National Forest. The primary objective of this study is to guide and evaluate aspen

restoration treatments by monitoring the response of a suite of landbird species associated

with a broad range of aspen habitat characteristics. In this report we incorporate results

from 2009 into those from 2004 – 2008 and use the knowledge gained from this

additional information to help guide future restoration treatments and long-term

management of aspen habitat on the Lassen National Forest.

Project Area All avian survey work was conducted on the Lassen National Forest in the Eagle

Lake and Almanor Ranger Districts at the junction of the Sierra Nevada and Cascade

Mountains of California (Lat 400 N, Long 1200 W). Sites ranged in elevation from

approximately 1500 – 2000 meters (Figure 1).


26

Methods Aspen Sampling Design

For all aspen sites we used GIS layers containing polygons of known aspen stands

based upon aspen inventories conducted by Forest Service staff. In the Eagle Lake

Ranger District (ELRD) we selected sites non-randomly that represent the range of

conditions in which aspen are found throughout the District. We limited our selection to

areas that could be covered by one observer in a four-hour morning count window and

that contained enough acres of aspen habitat to fit a minimum of 4 point count stations

with at least 220 meter spacing between points. We attempted to maximize the number of

post-treatment sites, which were limited in number, as they could provide us with

information on bird response to aspen treatments that were already five to nine years old.

The transects with treated stands on the ELRD in 2009 included Harvey Valley, Pine

Creek, Martin Creek, Feather Lake, and Butte Creek.

In the Almanor Ranger District (ARD) we selected sites that were within

proposed aspen enhancement projects (e.g., Minnow – Coon Hollow, Creeks II – Ruffa,

Brown’s Ravine, Feather – West Dusty 1-3, Lott’s – Philbrook/Coon Hollow, and Mini –

Robber’s Creek) and established points with at least 220 meter spacing in delineated

aspen polygons. Two additional transects, Willow Creek and West Dusty 4 were once

part of proposed projects but were dropped for various reasons. A total of 6 points (four

points on the West Dusty 3 transect, one point on the West Dusty 1 transect, and one

point on the Willow Creek transect) were treated as of the 2009 breeding season on the

ARD.

On both districts we attempted to maximize the number of points within the

delineated aspen stands in the areas selected. In some areas where stands were not in high

densities, we limited transect size to allow for the extra time to walk between stands in

order to allow for completion within the limited morning hours allowed by the

standardized protocol. Generally, the first stand chosen was the one closest to the nearest

road. Once the first stand was chosen, the next closest stand that was at least 200 meters

from the previous was selected, and so on. All sites were selected without previous

knowledge of the local micro habitat attributes or condition.


27

Survey Protocol

Standardized five minute unlimited distance variable circular plot point count

censuses (Reynolds 1980, Ralph et al. 1993) were conducted at 181 stations along 18

transects in 2009 (Table 1, Figure 1, and Appendix 1). All birds detected at each station

were recorded along with the exact distance from the observer where it was first detected

(to the nearest meter). Birds flying above the station in transit but not observed landing

were recorded separately. The method of initial detection (song, visual or call) for each

individual was recorded. Counts began around local sunrise and were completed within

four hours. Each transect was surveyed twice between 15 May and 1 July in each year,

including 2009 (Table 1). An electronic range finder was used to assist with distance

estimation at each point count station and all observers had previous songbird field work

experience and went through intense three week training on bird identification and

distance estimation.

Table 1. Aspen point count transects, ranger district, number of stations, and dates surveyed in 2009 in Lassen National Forest.

Site Name # of Stations

Ranger District

Date, 1st Survey Date, 2nd Survey

Brown’s Ravine Aspen 4 Almanor 6/14/2009 6/26/2009 Coon Hollow Aspen 14 Almanor 6/14/2009 7/1/2009 Philbrook Aspen 10 Almanor 6/14/2009 7/1/2009 Robber’s Creek Aspen 16 Almanor 5/28/2009 6/23/2009 Ruffa Aspen 12 Almanor 6/14/2009 7/1/2009 West Dusty Aspen 1 10 Almanor 5/26/2009 6/21/2009 West Dusty Aspen 2 6 Almanor 5/28/2009 6/24/2009 West Dusty Aspen 3 8 Almanor 5/26/2009 6/24/2009 West Dusty Aspen 4 8 Almanor 5/26/2009 6/21/2009 Willow Creek Aspen 9 Almanor 5/28/2009 6/21/2009 Butte Creek Aspen 8 Eagle Lake 5/27/2009 6/30/2009 Crazy Harry Aspen 7 Eagle Lake 5/29/2009 6/30/2009 Feather Lake Aspen 5 Eagle Lake 5/29/2009 6/30/2009 Harvey Valley Aspen 15 Eagle Lake 5/28/2008 6/20/2008 Lower Pine Creek Aspen 12 Eagle Lake 5/27/2009 6/22/2009 Martin Creek Aspen 11 Eagle Lake 5/25/2009 6/29/2009 Pine Creek Aspen 14 Eagle Lake 5/27/2009 6/22/2009 Susan River Aspen 12 Eagle Lake 5/29/2009 6/29/2009


28

Analyses Avian community point count analysis was restricted to a subset of the species

encountered. We excluded species that do not breed in the study area as well as those that

are not adequately sampled using the point count method (e.g., waterfowl, kingfisher, and

raptors). We also excluded European Starling and Brown-headed Cowbird from analysis

of species richness and total bird abundance because they are invasive species regarded

as having a negative influence on the bird community. However, we did investigate the

abundance of these two species separately.

Species richness

We present species richness as the average number of species detected within 50

meters per point across visits within a year for the species adequately sampled using the

point count method.


The index of total bird abundance is the mean number of individuals detected per

station per visit. This number is obtained by dividing the total number of detections

within 50 meters by the number of stations and the number of visits.

Index of Species Abundance

An index of the abundance of species was calculated as the total detections of a

given species within 50m of an observer per point count visit. For sites with multiple

years (most) we summed the detections and then divided by total visits across years

versus averaging the means for each year.

Statistical Tests

We employed a suite of statistical tests in comparing treated aspen to untreated

aspen. Negative binomial regression was used to test for differences in indices of

abundance of individual species between treated and untreated aspen stands; while linear

regression was used to compare the community indices of species richness and total bird

abundance. The test statistic (F for linear & Likelihood Ratio for negative binomial) and


29

p-values are presented. For the analysis of trends, linear regression was used with year as

the independent variable and we included a quadratic term for year if the linear fit was

poor. F-tests were used to evaluate the addition of the quadratic term. For all tests

significance was assumed at an α = 0.05 level. Stata 10.0 statistical software was used to

conduct all statistical analyses (Stata Corp 2007).

Chapter 2. Aspen Enhancement PRBO Avian Monitoring in the Plumas & Lassen National Forests - 2008

30

Figure 1. Location of PRBO Aspen point count stations in the Lassen National Forest surveyed in 2009.


31

Results In 2009, total bird abundance in aspen stands monitored across the two ranger

districts ranged from a high of 7.83 at Ruffa Aspen to a low of 2.86 at Crazy Harry, and

species richness ranged from 10.67 at Ruffa Aspen to 4.29 at Crazy Harry (Table 2). The

mean total bird abundance by transect in 2009 was 5.29 while the mean species richness

was 7.23. In comparison, total bird abundance in upland unburned habitat in the Plumas-

Lassen study area in 2009 was 5.08 and species richness was 6.37.

We compared the total bird abundance and species richness at untreated aspen

sites in the ARD to untreated aspen sites in the ELRD in 2009. Species richness was 7.98

in the ARD and 6.60 in the ELRD. Total bird abundance in the ARD was 5.84 compared

to 4.90 in the ELRD (Figure 2); these differences were not statistically significant. When

sites in both ranger districts that have been treated were included, both species richness

and total bird abundance decreased slightly in both districts but these changes were not

statistically significant (Figure 2).

When data from all years were combined, total bird abundance and species

richness were higher at treated sites compared to untreated sites on the Eagle Lake

Ranger District between 2006 and 2009 (Figure 3). Across this four year period, total bird

abundance averaged 5.54 at treated sites and 4.53 at untreated sites (F = 4.25, p = 0.04).

Species richness at treated sites averaged 6.99 compared to 6.33 at untreated sites (F =

0.81; p<0.37).


32

Table 2. Mean per point total bird abundance (detections/point/visit) and species richness (within 50 m of observers) at aspen sites surveyed in the Lassen National Forest from 2004 – 2009. Sites not surveyed are represented by double dashes. Coon Hollow and Philbrook transects were surveyed only once in 2008 due to fire access restrictions, thus they were not included in 2008 figures.

Station Total Bird Abundance Species Richness 2004 2005 2006 2007 2008 2009 2004 2005 2006 2007 2008 2009 Ruffa Aspen 5.72 7.11 5.92 6.88 6.33 7.83 7.56 7.33 7.50 8.92 8.42 10.67Brown’s Ravine 2.38 3.25 4.13 3.75 2.75 5.63 2.75 5.25 6.25 5.00 4.25 7.75 Butte Creek 4.63 5.81 7.31 5.69 5.50 7.13 5.75 8.00 9.63 8.38 7.75 8.63 Coon Hollow -- -- -- 4.75 -- 6.86 -- -- -- 6.71 -- 8.43 Crazy Harry 4.50 4.00 5.43 3.64 3.57 2.86 6.43 5.43 8.00 5.85 5.71 4.29 Feather Lake 4.60 7.40 5.30 9.50 8.00 4.80 6.40 7.20 5.80 7.80 7.80 6.20 Harvey Valley 3.47 3.03 5.93 4.17 2.43 4.50 4.93 4.47 6.93 4.67 3.47 6.13 Lower Pine Creek 4.00 2.67 4.04 4.67 3.96 5.21 5.75 4.42 5.92 6.83 6.17 7.00 Martin Creek 3.78 4.18 3.91 6.32 5.86 3.73 5.09 5.45 5.27 8.00 8.36 5.27 Philbrook -- -- -- 3.65 -- 6.10 -- -- -- 5.30 -- 8.80 Pine Creek 4.60 4.57 5.90 5.04 4.71 4.36 5.93 6.43 7.21 7.00 6.86 6.29 Robber’s Creek -- -- 5.72 5.78 5.09 4.94 -- -- 7.63 7.31 7.63 7.12 Susan River 3.67 3.13 3.09 4.92 1.29 5.58 4.75 5.00 4.50 6.50 2.25 7.83 West Dusty 1 -- -- 3.75 4.30 3.00 3.80 -- -- 5.50 6.80 5.00 5.30 West Dusty 2 -- -- 3.33 3.67 4.08 3.83 -- -- 4.00 3.67 5.67 5.50 West Dusty 3 -- -- 3.63 3.81 3.19 4.63 -- -- 5.50 5.63 5.38 6.38 West Dusty 4 -- -- 4.75 5.25 4.56 6.56 -- -- 6.75 7.88 5.75 8.63 Willow Creek -- -- 4.28 5.44 4.61 6.00 -- -- 5.33 7.22 6.78 8.44 Total 4.16 4.67 5.36 5.32 4.42 5.29 5.53 5.90 6.68 6.79 6.08 7.23


33

Figure 2. Mean per point species richness (per year) and total bird abundance (per visit) based on detections within 50 meters of observers at treated and untreated aspen sites on Almanor and Eagle Lake ranger districts in 2009 with standard error.

Figure 3. Mean per point species richness and total bird abundance at treated and untreated aspen sites on the Eagle Lake Ranger District from 2006 – 2009 compared to coniferous forest in the Plumas-Lassen study area from 2003 – 2006 with standard error.

Almanor vs. Eagle Lake 2009

0

1

2

3

4

5

6

7

8

9

Species Richness Total Bird Abundance

Almanor Untreated

Almanor Total

Eagle Lake Untreated

Eagle Lake Total

Treated vs. untreated aspen

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

Species Richness Total Bird Abundance

Treated Aspen

Untreated Aspen

Conifer Forest


34

Species richness decreases substantially in 2009 at treated sites on ELRD to its

lowest value since the beginning of the study (Figure 4). Including a quadratic term for

year improved model fit (F = 8.2, p = 0.005). Species richness at untreated sites on ELRD

continued to show a significant increasing linear trend (F = 9.6, p < 0.002) between 2004

and 2009. Total bird abundance from 2004 through 2009 at treated sites also decreased

to its lowest value since the beginning of the study and including a quadratic term for

year improved model fit for this metric as well (F = 10.0, p = 0.002). Untreated sites

continued to show a significant increasing linear trend (F = 6.63, p = 0.01).

Figure 4. Mean per point species richness (with standard error) at treated and untreated aspen sites from 2004 -2009 in Eagle Lake Ranger District (Lassen National Forest) with standard error and fitted linear and quadratic trend lines.

Species Richness

0

1

2

3

4

5

6

7

8

9

2004 2005 2006 2007 2008 2009

# of

Spe

cies

/Poi

nt

Treated

Untreated


35

Figure 5. Total bird abundance per point count visit (with standard error) by year at treated and untreated aspen sites from 2004 - 2009 on the Eagle Lake Ranger District (Lassen National Forest) with standard error and fitted linear and quadratic trends.

We investigated an index of the abundance of ten of the twelve previously

identified aspen focal species (Burnett in press), at treated aspen, untreated aspen, and

conifer forest across the six-year study period in both ranger districts. We also included

Mountain Chickadee, another potential focal species. There were not adequate detections

of Swainson’s Thrush and Olive-sided Flycatcher – the remaining two focal species – to

include them in the analysis.

Six of the eleven species were significantly more abundant in treated aspen than

untreated aspen; each of these six species were also more abundant in aspen of any kind

compared to coniferous forest in the region (Table 3, Figure 6). Red-breasted Sapsucker,

Hairy Woodpecker, Mountain Bluebird, Tree Swallow, Mountain Chickadee and

Chipping Sparrow were all significantly more abundant in treated aspen than untreated

aspen. Additionally, total bird abundance was significantly greater in treated stands

compared to untreated stands while species richness was similar. Western Wood-Pewee

and Warbling Vireo showed a small non-significant difference between treated and

untreated aspen though these species were far more abundant in aspen stands than conifer


0

1

2

3

4

5

6

7

8

2004 2005 2006 2007 2008 2009

# of

Indi

vidu

als/

Poi

nt/ V

isit

Treated

Untreated


36

forest. Only two focal species, Dusky Flycatcher and MacGillivray’s Warbler, remained

more abundant in untreated than treated aspen, with a significant difference for

MacGillivray’s Warbler, and both were similarly abundant in conifer forest as in aspen.

Table 3. Species Richness, total bird abundance, and an index of the abundance of ten aspen focal species at treated and untreated sites across the Lassen National Forest, 2006-2009. P-value is from linear (species richness & total bird abundance) or negative binomial regression (all other metrics) comparing treated to untreated aspen. Means from conifer forest in the Plumas-Lassen Administrative Study from 2003-2006 are also presented for comparison.

Treated Aspen

Untreated Aspen P

Conifer Forest

Species Richness 6.94 6.63 0.23 5.47 Total Bird Abundance 5.48 4.76 <0.01 4.08 Red-breasted Sapsucker 0.22 0.15 0.03 0.03 Hairy Woodpecker 0.15 0.08 0.01 0.03 Western Wood-Pewee 0.17 0.16 0.66 0.02 Dusky Flycatcher 0.16 0.20 0.29 0.26 Warbling Vireo 0.52 0.50 0.75 0.09 Tree Swallow 0.42 0.03 <0.01 0.01 Mountain Chickadee 0.62 0.44 <0.01 0.28 Mountain Bluebird 0.11 0.00 <0.01 0.00 Oregon Junco 0.50 0.49 0.82 0.36 Chipping Sparrow 0.20 0.07 <0.01 0.01 MacGillivray's Warbler 0.07 0.14 0.01 0.11

We investigated the effect of time since treatment on total bird abundance and

species richness during 2004-2009 for all aspen sites on the Lassen National Forest while

controlling for year. When all treated and untreated sites are included (with those that

have not been treated coded as zero) there is a significant positive effect (F = 15.0,

p<0.01) of time since treatment on total bird abundance (Figure 7). When untreated sites

were not included there was no effect of time since treatment (F = 0.07, p = 0.79) on total

bird abundance. For species richness, the effect of time since treatment was positive and

significant when untreated sites were included (F = 4.96, p = 0.03; Figure 8), but was not

when they were excluded (F = 1.41, p = 0.24). This pattern is consistent with what we

have observed in previous years.


37

Figure 6. Abundance per point count visit ± standard error for the seven aspen focal species with a significant difference in abundance (p<0.05) between treated and untreated aspen stands in the Lassen National Forest from 2006-2009. Conifer habitat indices are shown for comparison using data from the Plumas-Lassen Administrative Study from 2003 – 2006.

The time since aspen stands had been treated had a significant effect on the

abundance of six of the ten focal species (Figure 9). For Red-breasted Sapsucker and

Chipping Sparrow the effect was positive and the best fit was linear. For each of the other

five species the effect was more complex. For Hairy Woodpecker, Tree Swallow,

Mountain Bluebird, and Dusky Flycatcher, the best fit model was one with a quadratic

effect of treatment. For all of these except Dusky Flycatcher there was an increasing

trend peaking in the four to five year post treatment period followed by a significant

decrease after that. Dusky Flycatcher was the only species to show a negative effect of

time since treatment; it decreased in the years immediately following treatment but

showed an increase in abundance in the longest time since treatment interval.

MacGillivray’s Warbler also showed a weakly significant (p = 0.06) negative linear trend

with time since treatment.

Treated Vs. Untreated Aspen

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

Red-breastedSapsucker

HairyWoodpecker

Tree Sw allow MountainChickadee

MountainBluebird

ChippingSparrow

MacGillivray'sWarbler

Det

ectio

ns p

er v

isit

Treated Aspen

Untreated Aspen

Conifer Forest


38

Figure 9. The mean abundance per point count visit with standard error and predicted values for the six focal species showing a significant effect of time since treatment from 2004 - 2009. Graphs show time since treatment in intervals for illustrative purposes but regression was conducted with all data. All aspen sites surveyed on the Lassen National Forest are included. All untreated sites were coded as zero years post treatment.

Red-breasted Sapsucker

0

0.1

0.2

0.3

0.4

0 1 to 2 3 to 4 5 to 6 >6

Years Post Treatment

Det

ectio

ns/P

oint

Cou

ntVi

sit

Hairy Woodpecker

0

0.1

0.2

0.3

0.4

0 1 to 2 3 to 4 5 to 6 >6


Det

ectio

ns/P

oint

Cou

ntVi

sit

Tree Swallow

00.20.40.60.8

1

0 1 to 2 3 to 4 5 to 6 >6


Det

ectio

ns/P

oint

Cou

ntVi

sit

Mountain Bluebird

00.050.1

0.150.2

0.250.3

0 1 to 2 3 to 4 5 to 6 >6


Det

ectio

ns/P

oint

Cou

ntVi

sit

Chipping Sparrow

0

0.1

0.2

0.3

0.4

0 1 to 2 3 to 4 5 to 6 >6


Det

ectio

ns/P

oint

Cou

ntVi

sit

Dusky Flycatcher

0

0.1

0.2

0.3

0.4

0 1 to 2 3 to 4 5 to 6 >6


Det

ectio

ns/P

oint

Cou

ntVi

sit


39

In Harvey Valley, species richness and total bird abundance increased following

treatment (Figure 10). Species richness increased at treated sites 19% over pre-treatment

levels while untreated sites increased 11%. Total bird abundance increased 14% at treated

sites following treatment while it decreased 11% at untreated sites. Due to relatively

small sample size (15 total points) none of these differences were statistically significant.

Figure 10. Species richness and total bird abundance at six reference and nine treated sites before (2004-2007) and after (2009) treatment with 95% confidence intervals for the Harvey Valley Aspen transect. All treatments were implemented in the winter of 2008 but not completed until after the breeding season, so 2008 was excluded from analysis.

Harvey Valley Species Richness

0123456789

Reference Reference Treated Treated

Before After Before After

Spec

ies/

Poin

t Per

Yea

r

Harvey Valley Total Bird Abundance

0

1

2

3

4

5

6

7



Det

ectio

ns/V

isit


40

Similar to Harvey Valley, treated stands in the Feather aspen project on the ARD

showed a modest increase in 2009 the first year after treatment was implemented (Figure

11). Species richness increased at treated sites 17% while it declined 4% at untreated

sites. Total bird abundance increased 24% at treated sites while it increased 11% at

untreated sites. Again, with small sample sizes none of these differences were statistically

significant.

Figure 11. Species richness and total bird abundance at nine treated aspen sites and five

untreated aspen sites in the Feather aspen restoration project with 95% confidence

intervals. All sites were treated in the fall of 2008.

Species Richness West Dusty 3

0123456789

10



Spec

ies/

Poin

t per

Yea

r

Total Bird Abundance West Dusty 3

0

1

2

3

4

5

6

7

8



Indi

vidu

als/

Poin

t Vis

it


41

At the Pine Creek aspen site, the trends in species richness and total bird

abundance have been decreasing in the last three years from highs recorded in 2006 and

in 2009 were at similar levels to those recorded in 2004 (Figure 12). The inclusion of a

quadratic term in the model did significantly improve the fit compared to a linear model.

Figure 12. Mean per point species richness and total bird abundance (<50m from observers) at the Pine Creek Aspen transect from 2004 – 2009 with 95% confidence intervals. The majority of treatment was implemented in the winter of 2003/2004, fall 2006, and winter 2007/2008.

Discussion

Aspen habitat on the Lassen National Forest harbors greater total bird abundance,

species richness, and abundance of almost all of the aspen focal species compared to

conifer-dominated forest in the region. On average, aspen habitat on the ARD harbored

greater species richness and total bird abundance compared to the ELRD, though there

continues to be considerable site to site and annual variation in these indices as well as in

the abundance of individual species.

Treated vs. Untreated

In the ELRD, the short term response of the avian community to aspen treatments

has been decidedly positive. From 2004 - 2009 species richness and total bird abundance

Pine Creek Aspen

0

1

2

3

4

5

6

7

8

9

10

2004 2005 2006 2007 2008 2009

Year

Spe

cies

Per

Poi

nt o

r In

divi

dual

s/V

isit

Species Richness



42

showed a significant increase at both treated and untreated aspen. However, in 2009 these

consistent increasing trends showed a downturn at treated sites while they continued to

increase at untreated sites. The fit of the trend at untreated site is not as good as that for

treated sites with considerable annual variation. The untreated sites used as reference

sites have almost all been released from livestock grazing pressure which has been shown

to result in an increase in bird species richness and the abundance of many of our aspen

focal species (Earnst et al. 2006). Thus they may be undergoing passive restoration

resulting in the observed increasing trends. As for the decline in richness and abundance

at treated sites in 2009, it appears as though the short-term benefits of aspen treatments

may be rather short-lived. However, due to potential bias in how treated sites were

selected and the lack of true controls (untreated sites have been switching into the treated

sample as more sites get treated) and the potential bias in how sites are selected for

treatment by the Forest Service (selecting poorer quality sites with unhealthier aspen), we

continue to advise some caution in interpreting these trends.

However, based on several recently treated sites, the pattern of an immediate

increase following treatment followed by a slow but steady declines remains consistent.

For example, Harvey Valley, treated in winter 2007-2008 showed an increase in richness

and abundance in 2009 compared to the mean from the four years prior to treatment as

did West Dusty 3 (part of the Feather project treated in 2008) on the Almanor Ranger

district. However, Pine Creek showed a substantial decrease in 2009 from previous years.

The decline at this site may be a result of the riparian areas being treated in 2007, further

reducing the habitat for conifer associated species; but we also observed a decline here in

many of the focal species in 2009. We also observed decreases in these metrics at Feather

Lake in 2009. We had originally hypothesized treatments would result in a decrease in

species richness and abundance in the lag between the loss of foliage volume and

structural diversity from conifer removal and the time it takes for aspen to regenerate. As

the Pine Creek and Feather Lake represent 45% of our treated sample and the majority of

our older sites, the decreases observed here in 2009 appear to be driving the overall

trends. Continued monitoring will help provide greater insight into these patterns in order

to more fully determine the response of the avian community to treatments over time.


43

While we documented declines of many focal species in treated stands in 2009,

the overall abundance of most of the focal species from 2006 – 2009 are still higher at

treated sites than at untreated. All of the seven focal species that were significantly more

abundant in treated aspen compared to untreated aspen were also significantly more

abundant in treated aspen than conifer forest. Chipping Sparrow, declining at a rate of

3.4% per year from 1968-2007 in the Sierra Nevada (Sauer et al. 2008) have been

increasing significantly in treated aspen stands and that patterned continued to hold in

2009. This species often nests in understory trees in areas with a substantial herbaceous

layer where it forages on insects and seeds (Middleton 1998). Thus, treated aspen stands

appear to be ideal habitat for this species, which is very rare in conifer-dominated forest

in the region. Likewise, Mountain Bluebird and Tree Swallow are all but absent from

conifer forest and untreated aspen, but are fairly common to abundant (respectively) in

treated aspen. Mountain Bluebird has been declining over the past 40 years in the Sierra

Nevada at a rate of 2.5% per year, though due most likely to their rarity this trend is not

significant (Sauer et al. 2008).

All of the aspen focal species are more abundant or as abundant in treated aspen

compared to untreated aspen with the exception of MacGillivray’s Warbler. Restoring

dense willow and alder cover in riparian habitat within aspen stands will be key to

improving habitat for MacGillivray’s Warbler – as they are rarely found in aspen stands

away from riparian areas. They are quite abundant at Martin Creek in the treated and

fenced stand with a dense understory. Removing conifers from riparian zones that can

support deciduous riparian vegetation and reducing the grazing in order to allow a dense

understory to return will benefit this species and likely a number of bird species that rely

on this unique but limited habitat.

Aspen habitat often supports a diverse and abundant guild of cavity nesting

species, with many studies showing cavity nesters disproportionately select aspen trees

for nesting (Li and Martin 1991, Dobkin et al. 1995, Martin and Eadie 1999, Martin et al.

2004). While aspen often contain relatively high numbers of natural cavities, secondary

cavity nesting species have been found to nest predominantly in woodpecker created

holes in both live aspen and aspen snags (Li and Martin 1991, Dobkin et al. 1995, Martin

and Eadie 1999). Both Red-breasted Sapsucker and Hairy Woodpecker continued to be


44

significantly more abundant in treated aspen than untreated aspen or conifer forest in the

region. At numerous treated aspen – including those at Feather Lake, Butte Creek, Pine

Creek, and Martin Creek – we confirmed active woodpecker nest cavities within treated

stands. In 2008 we documented seven species of woodpecker present during one visit to

the Pine Creek transect (Hairy, Downy, White-headed, Black-backed, Pileated, Northern

Flicker, and Red-breasted Sapsucker). Removing encroaching conifers from within and

surrounding aspen stands, resulting in the expansion of stands and increased density of

large diameter aspen stems over time, should increase habitat for woodpeckers. There is

little doubt that aspen supports far greater abundance of woodpeckers than coniferous

forest and that treating aspen results in even greater increases in these species of

management interest. In turn, woodpeckers are a critical component of the aspen

community as the source of cavities for an abundant and diverse group of secondary

cavity nesting birds, many of which use these aspen areas in relatively high numbers

(e.g., Mountain Bluebird, Tree Swallow, and Mountain Chickadee).

Time Since Treatment

The time since aspen stands had been treated continued to show a generally

positive but complex effect on many of the focal species once 2009 data, including five

treated sites on the ARD were added. The best fit models for four of the six species

showing a significant effect of time since treatment included a quadratic term. For three

of these species their abundance peaked in the three to four years post-treatment time

period and then declined in the following time intervals. This suggests the immediate

positive increase after aspen treatments may be relatively short-lived for at least some

species and mimics the general pattern observed with species richness and total bird

abundance. However, it is important to remember that that the post-treatment sample is

relatively small (42 sites in 2009) and any inherent biases in how sites were chosen for

treatment could easily be magnified in this analysis.

These patterns suggest that no one aspen condition or post-treatment time period

is ideal for all species. The conditions created immediately following aspen treatments

may be mimicking the structure found in natural post-disturbance habitat that often

supports greater numbers of some of these species (Raphael et al. 1987). Though Hairy


45

Woodpecker, Tree Swallow, and Mountain Bluebird showed marked declines at sites

over four years post-treatment, each was more abundant in these older sites than they

were in untreated aspen. These results continue to support the notion that management of

aspen habitat should consider the importance of disturbance and the early successional

habitat in which it results.

Conclusions

Our results from 2009 continue to suggest that aspen treatments employed on the

LNF are having a positive effect on the aspen breeding bird community. Key species

such as Red-breasted Sapsucker, Mountain Bluebird, and Chipping Sparrow all appear to

have had a short-term positive response to treatment. Based on these and previous results,

we believe that treatments that increase the size and health of aspen stands will be highly

beneficial to aspen focal bird species in the Lassen National Forest in the long-term and

should be a top priority of land managers here. We also recognize the value of continuing

the monitoring of landbird communities in treated aspen habitat in order to better

understand the complex patterns we have observed in recent years as treated stands

mature.

Acknowledgements

Funding for our Aspen project was provided by the Lassen National Forest and

Herger Feinstein Quincy Library Group Forest Recovery Act monitoring funds. We

especially would like to thank Coye Burnett, Tom Frolli, Bobette Jones, Tom Rickman,

and Mark Williams of the Lassen National Forest - for their support and assistance with

this project. We also wish to thank Tim Guida, crew leader, and Nathan Fronk and Luke

Owens, our 2009 field crew.


46

Literature Cited Bartos, D.L. and R.B. Campbell, Jr. 2001. Landscape dynamics of aspen and conifer

forest. In Sustaining aspen in Western Landscapes: Symposium Proceedings. Grand Junction, CO: Rocky Mountain Research Station. USDA Forest Service. RMRS -18:5-14.

Burnett, R.D. In press. Integrating Avian Monitoring into Forest Management: Pine-Oak

and Aspen Enhancement on the Lassen National Forest. USFWS Technical Report.

Dobkin, D. S., A. C. Rich, J. A. Pretare, and W. H. Pyle. 1995. Nest-site relationships

among cavity-nesting birds of riparian and snowpocket aspen woodlands in the northwestern Great Basin. Condor 97:694-707.

Earnst, S.L., J.A. Ballard, and D.S. Dobkin. 2005. Riparian songbird abundance a decade

after cattle removal on Hart Mountain and Sheldon National Wildlife Refuges. PSW-GTR 191:550-558.

Finch, D.M. and R.T. Reynolds. 1987. Bird response to understory variation and conifer

succession in aspen forests. Pages 87-96, In J. Emmerick et al. eds. Proceedings of issues and technology in the management of impacted wildlife. Thorne Ecological Institute, Colorado Springs, CO.

Flack, J.A. Douglas. 1976. Bird populations of aspen forests in western North America.

Ornithological Monographs No. 19. The American Ornithologist’s Union. Heath, S.K. and G. Ballard. 2003. Patterns of breeding songbird diversity and occurrence

in riparian habitats of the Eastern Sierra Nevada. In California Riparian Systems: Processes and Floodplain Management, Ecology, and Restoration. 2001 Riparian Habitats and Floodplains Conf. Proc. (P. M. Faber, ed.). Riparian Habitat Joint Venture, Sacramento, CA.

Jones, B.E., T.H. Rickman, A. Vasquez, Y. Sado, K.W. Tate. In press. Removal of

invasive conifers to regenerate degraded aspen stands in the Sierra Nevada. Restoration Ecology 13:373-379.

Li, P., and T. E. Martin. 1991. Nest-site selection and nesting success of cavity-nesting

birds in high elevation forest drainages. Auk 108:405-418. Martin, K., K. E. H. Aitken, and K. L. Wiebe. 2004. Nest-sites and nest webs for cavity-

nesting communities in interior British Columbia: nest characteristics and niche partitioning: Condor. 106 5–19.

Martin, K. and J.M. Eadie. 1999. Nest webs: A community wide approach to the


47

management and conservation of cavity nesting forest birds. Forest Ecology and Management 115:243-257.

Mueggler, W.F. 1985. Forage. In Aspen: Ecology and management in the Western United States. USDA Forest Service General Technical Report RM-119:129-134. Middleton, Alex L. 1998. Chipping Sparrow (Spizella passerina), The Birds of North

America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/334

Ralph, C. J., G. R. Geupel, P. Pyle, T. E. Martin, & D. F. DeSante. 1993. Field Methods

for Monitoring Landbirds. USDA Forest Service Publication, PSW-GTR 144, Albany, CA.

Raphael, M.G., Morrison, M.L., Yoder-Williams, M.P. 1987. Breeding bird populations

during twenty five years of post-fire succession in the Sierra Nevada. The Condor 89, 614-626.

Reynolds, R.T., J.M. Scott, and R.A. Nussbaum. 1980. A variable circular plot method

for estimating bird numbers. Condor 82:309:313.

Richardson, T.W. and S.K. Heath. 2005. Effects of conifers on aspen breeding bird communities in the Sierra Nevada. Transactions of the Western Section of the Wildlife Society 40: 68 – 81.

Sauer, J. R., J. E. Hines, and J. Fallon. 2008. The North American Breeding Bird Survey,

Results and Analysis 1966 - 2007. Version 10.13.2007. USGS Patuxent Wildlife Research Center, Laurel, MD.

Stata Corp. 2007. Intercooled Stata 10.0 for Windows. Stata Corp. LP College Station,

TX.

48

Chapter 3. Resident and Neotropical Migratory Bird Monitoring in Mountain Meadows: 2009 Report

Ryan D. Burnett

PRBO Conservation Science

Chapter 3. Mountain Meadows PRBO Avian Monitoring in the Lassen National Forests - 2009

49

Background and Introduction

Mountain meadows are among the most important habitats for birds in California

(Siegel and DeSante 1999, Burnett and Humple 2003, Burnett et al. 2005); they support

several rare and declining species and are utilized at some point during the year by almost

every bird species that breeds in or migrates through the Sierra Nevada. Meadows also

perform a vital role as watershed wetlands that store and purify drinking water for

millions of Californians. And yet, most of these meadows are in a degraded state and

their value for water storage and as critical habitat for birds and other wildlife has been

dramatically reduced.

In the Sierra Nevada, meadows have been heavily degraded or lost due to well

over a century of human activities including flooding, diversions, vegetation removal,

and overgrazing (SNEP 1996, Siegel and DeSante 1999). As far back as 1869, John Muir

lamented about the destruction of Sierra meadows by man, “….but as far as I have seen,

man alone, and the animals he tames, destroy these gardens.” Indeed few, if any,

meadows in the Sierra remain unaltered by human activities. The meadows that do

remain are in a compromised state and they are owned by a diverse set of interests

including private industry and utilities, state and federal agencies, and private ranches.

Though they have been altered, a number of meadows in the Feather River

watershed support populations of many declining and threatened riparian meadow bird

species, including Sandhill Crane, Swainson’s Thrush, Yellow Warbler, and Willow

Flycatcher. The area also supports breeding populations of 11 of the 16 California

Partners in Flight Riparian Focal Species (Humple and Burnett 2004, RHJV 2004). With

its high diversity and abundance of meadow bird species, including the largest population

of Willow Flycatcher in the Sierra Nevada region (Humple and Burnett 2004), the

Feather River watershed is a conservation hotspot for meadow birds.

Meadow conservation and management in the Feather River watershed and

throughout the Sierra Nevada will require a collaborative effort between different land

management agencies, county government, non-governmental organizations, and private

landowners. In order to manage for breeding bird populations, especially listed meadow-

dependent species such as Willow Flycatcher and Sandhill Crane, the Forest Service


50

needs to with the other meadow landowners in the area in order to ensure the long-term

viability of these and other bird species.

In this chapter we summarize results from point count surveys from meadows in

the Feather River watershed in 2009, including three new sites in the Last Chance Creek

watershed and one new site on the Eagle Lake Ranger District (ELRD). We use a suite of

meadow focal species to compare abundance and richness metrics between meadows and

provide recommendations for improving habitat for these and other species. We also

briefly report on our breeding and post-breeding mist-netting efforts at wet meadow sites

in the region.

Methods Site Selection Several considerations went into selecting meadow sites we sampled. Following

an inventory of 16 meadows in the Almanor Ranger District (ARD) of the Lassen

National Forest (LNF) between 2000 and 2001 we selected a subset of those sites to

continue long-term meadow monitoring within. We were interested in surveying sites that

supported or could support a riparian deciduous shrub (willows/alders) bird community

and especially those sites that had recently undergone management changes (e.g. active

restoration and/or removal of grazing). With these two considerations in mind we

attempted to choose sites that represented a range of elevations and habitat conditions.

With this strategy, we believe the sites selected are not totally representative of the range

of meadow conditions in the ARD area but represent some of the higher quality riparian

meadow bird habitat in the area. Sites within the Last Chance Watershed were added

within areas that have been restored or are slated to be restored in the next couple of

years. The Pine Creek Valley transect was established at the request of the ELRD in order

to investigate the difference in the avian community within and outside of a grazing

exclosure.

Point Count Censuses

Point count data allow us to measure secondary population parameters such as

relative abundance of individual bird species and species richness. This method is useful

for making comparisons of bird communities across time, locations, habitats, and land-


51

Figure 1. PRBO Northern Sierra meadow point count sites surveyed in 2009.


52

use treatments. Standardized five-minute multiple distance band point count censuses

(Reynolds et al. 1980, Ralph et al. 1995) were conducted at each of 94 stations along nine

transects in 2010 within the greater ARD area, 54 points in the Last Chance Creek

Watershed in eastern Plumas County, and 15 points in the Pine Creek Valley on the

ELRD for a total of 162 point count stations (Table 1). Point count stations were a

minimum of 50 meters from meadow edges where feasible; if the riparian corridor was

less than 100 meters wide, points were placed equidistant from each edge, and in most

cases points were located within 50 meters of stream channel (where they existed). At

each site points were spaced between 200 and 250 meters apart and were configured in a

manner that maximized spatial coverage of sites.

Table 1. PRBO Northern Sierra meadow point count transects with transect codes, year established, and dates surveyed in 2009.

All birds detected at each station during the five-minute survey were recorded.

Detections were placed within one of six categories based on the initial detection distance

from observer: less than 10 meters, 10-20 meters, 20-30 meters, 30-50 meters, 50-100

meters, and greater than 100 meters. Birds flying over the study area but not observed

using the habitat were recorded separately, and excluded from all analyses. The method

of initial detection (song, visual or call) for each individual was also recorded. Counts

began around local sunrise and were completed within four hours. Each transect was

visited twice each year between late May and the end of June. With the exception of

Transect Code # of

points Year

established2009

1st Visit 2009

2nd Visit Alkali Flat ALFL 18 2009 19-Jun 27-Jun Carter Meadow CAME 7 2004 16-Jun 30-Jun Clark’s Creek CKCR 18 2009 29-May 20-Jun Fanani Meadow FAME 8 2003 28-May 17-Jun Gurnsey Creek GUCR 10 1997 1-Jun 16-Jun Humbug Valley HUVA 17 2003 10-Jun 26-Jun Lower Last Chance Creek LLCH 18 2009 13-Jun 25-Jun Pine Creek Valley PCVA 15 2009 13-Jun 22-Jun Robber’s Creek ROCR 14 2004 12-Jun 29-Jun Soldier Meadow SOME 7 2001 28-May 17-Jun West Shore Lake Almanor WSLA 13 2004 2-Jun 18-Jun Yellow Creek Riparian YCRI 12 2001 5-Jun 19-Jun Yellow Creek PG&E YCPGE 6 2008 5-Jun 19-Jun Total 163


53

Lower Last Chance Creek, Alkali Flat, and Clark’s Creek, all surveys were conducted by

the author who has been conducting point counts in the Sierra Nevada for over a decade.

The three other sites were surveyed by two experts in Northern Sierra bird identification

that passed a double observer field test with the author prior to conducting counts. An

electronic range finder was used by all observers to assist with distance estimation at each

point count station.

Statistical Analysis

Point count analysis was restricted to a subset of the species encountered. We

excluded species that do not breed in the study area as well as those species that are not

adequately sampled using the point count method (e.g., shorebirds, waterfowl, raptors,

and swallows). For a number of the analyses we used a suite of meadow focal species

that represent a range of meadow bird habitat conditions and as a group are likely to

provide a better measure of the quality of meadow habitat than all species (Chase and

Geupel 2005; Table 2).

Table 2. Avian focal species (listed in taxonomic order) for meadow monitoring in the ARD and their conservation status. California Partners in Flight Riparian Focal species are noted in bold (RHJV 2004).

Species Conservation Status1 Sandhill Crane State Threatened Red-breasted Sapsucker Declining in the Sierra2; NTMB Willow Flycatcher State Endangered, USFS Sensitive, NTMB Warbling Vireo NTMB, Declining in the Western U.S. Swainson’s Thrush USFS Priority Land Bird Species, NTMB Black-headed Grosbeak NTMB Yellow Warbler State Species of Special Concern, NTMB

MacGillivray's Warbler NTMB Wilson's Warbler Significant Decline in Sierra2, NTMB Song Sparrow None Lincoln's Sparrow NTMB

1NTMB = Neotropical Migratory Bird 2 from Sauer et al. 2008.


54

Species richness

The species richness index used here was obtained by summing the species detected

within 50 meters of the observer across both visits to each point count station and then averaged

across all points in the transect. Similarly, focal species richness is the same calculation but

limited to the list of species in table 2. Presenting the mean species richness, as is done herein,

allows for comparisons between transects or habitats consisting of different numbers of point

count stations but does not provide a measure of the total number of species across an entire

transect.

Indices of Abundance

An index of total bird abundance, defined as the mean number of individuals detected per

station per visit, was calculated for each transect. This number is obtained by dividing the total

number of detections within 50 meters of the observer by the number of stations and the number

of visits. The same method was employed for creating focal species abundance (the total number

of individuals of all focal species combined) and for each individual focal species. Note that

Sandhill Crane was did not occur within 50m of observers but would not have been included in

these indices if it had as it is not adequately sampled using point counts (large territories and

shy).

Results Song Sparrow was the most abundant meadow bird focal species detected from 2003 –

2009 at the Almanor area meadows with and index of abundance of 1.17, followed by Yellow

Warbler at 1.04 (Figure 2). In the Last Chance Creek watershed these two species were also the

most abundant focal species with indices of abundance of 0.97 and 0.74 respectively (Figure 3).

Willow Flycatcher, a Forest Service sensitive and state threatened species, had an index of

abundance of 0.08 in the Almanor area while this species along with Wilson’s Warbler and

Lincoln’s Sparrow were not detected in the Last Chance watershed.


55

Figure 2. The mean abundance (+/- standard error) of nine meadow focal species per point count visit from 2003 – 2009 across all sites combined in wet riparian meadows in the Almanor Ranger District.

Figure 3. The mean abundance (+/- standard error) of nine meadow focal species per point count visit in 2009 across all sites combined in the Last Chance Creek watershed. Note Willow Flycatcher, Lincoln’s Sparrow, and Wilson’s Warble were not detected here in 2009.

Focal Species Abundance (Almanor Area)

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40

Song Sparrow

Yellow Warbler

MacGillivray's Warbler

Warbling Vireo

Wilson's Warbler

Lincoln's Sparrow

Willow Flycatcher


Black-headed Grosbeak

Detections/Point Count Visit

Focal Species Abundance (Last Chance Watershed)

0 0.2 0.4 0.6 0.8 1 1.2

Song Sparrow

Yellow Warbler

Black-headed Grosbeak


Warbling Vireo


Wilson's Warbler

Lincoln's Sparrow

Willow Flycatcher

Detections per Point Count Visit


56

Meadow Comparison

I compared species richness, total bird abundance, focal species richness, and focal

species total abundance across all sites in 2009. The mean species richness for all sites combined

was 6.09. Carter Meadow had the highest avian species richness with 8.86 species per point

(Figure 4). Carter Meadow was followed closely by Robber’s Creek and Yellow Creek at 8.79

and 8.75, respectively. All three of these sites had overall species richness significantly higher

than the average for all sites combined. The lowest species richness was for Yellow Creek PG&E

with 1.5 species per point. Other sites with significantly lower species richness than the average

for all sites combined were Pine Creek Valley, Lower Last Chance Creek, Soldier Meadow, and

Alkali Flat. The mean total bird abundance in 2009 for all sites combined was 6.02. Total bird

abundance was highest at Carter Meadow with 9.14 detections per point per visit (Figure 5). The

only other site with significantly higher total bird abundance than the mean for all sites combined

was West Shore Lake Almanor at 8.35. Sites with significantly lower total bird abundance than

the 2009 average were Yellow Creek PG&E at 1.5, Soldier meadow at 2.71, Pine Creek Valley

at 3.20, and Lower Last Chance Creek at 3.64.

Figure 4. Avian species richness (per point per year detections <50m) at 12 meadow sites in the Northern

Sierra Nevada in 2009 with 95% confidence intervals. The dashed line represents the mean for all sites

combined. Four letter site codes are defined in Table 1.

0123456789

101112

CAME FAME GUCR HUVA ROCR SOME WSLA YCRI YCPGE ALFL CKCR LLCH PCVA

Spe

cies

/Poi

nt/Y

ear

Species Richness


57

Figure 5. Total bird abundance (per point per visit detections <50m) at 12 meadow sites in the Northern

Sierra Nevada in 2009 with 95% confidence intervals. The dashed line represents the mean for all sites

combined. Four letter site codes are defined in Table 1.

The mean focal species richness for all sites combined in 2009 was 2.38. Focal species

richness was highest at Fanani Meadow with 4.38 species per point (Figure 6). The only other

sites with focal richness significantly higher than the 2009 average were Gurnsey Creek with 4.0

and Carter Meadow at 3.43. Lower Last Chance Creek (1.72), Alkali Flat (1.17), Yellow Creek

PG&E (0.0), and Pine Creek Valley (0.0) all had focal richness significantly lower than the

average.

The mean focal species abundance for all sites combined in 2009 was 2.81. Focal species

abundance was highest at Gurnsey Creek with 4.55 detections per point per visit followed by

West Shore Lake Almanor with 4.19 (Figure 7). These meadows were the only two with

significantly higher focal species abundance than the average from all sites combined. The

meadows with significantly lower focal species abundance than the 2009 average were Lower

Last Chance Creek (1.75), Alkali Flat (1.56), Soldier Meadow (0.93), Yellow Creek PG&E (0.0),

and Pine Creek Valley (0.0).

0

2

4

6

8

10

12

CAME FAME GUCR HUVA ROCRSOME WSLA YCRIYCPGEALFL CKCR LLCH PCVA

Indi

vidu

als/

Poi

nt/V

isit



58

Figure 6. Avian meadow focal species richness (per point per year detections <50m) at 12 meadow sites in the

Northern Sierra Nevada in 2009 with 95% confidence intervals. The dashed line represents the mean for all

sites combined. Four letter site codes are defined in Table 1.

Figure 7. Meadow focal species abundance (per point per visit detections <50m) at 12 meadow sites in the

Northern Sierra Nevada in 2009 with 95% confidence intervals. The dashed line represents the mean for all

sites combined. Four letter site codes are defined in Table 1.

0

1

2

3

4

5

6

7


Spe

cies

/Poi

nt/Y

ear

Focal Species Richness

0

1

2

3

4

5

6

7


Indi

vidu

als/

Poi

nt/V

isit

Focal Species Abundance


59

PG&E and its partners have been considering restoring a portion of Yellow Creek where

it enters the valley floor in Humbug Valley. We have been monitoring birds upstream of this area

on Yellow Creek since 2003. In 2008, an additional six point count stations were added at the

downstream end of the existing transect in order to sample the project area (YCPGE). Using data

from 2008 and 2009, I compared several avian metrics between the project area and the Forest

Service land immediately above the proposed project area (Figure 8). Species richness, total bird

abundance, focal richness, and the abundance of six focal species were all significantly lower in

the project area. In fact, we did not detect a single focal species in two years within the project

area. The primary species detected in the project were Horned Lark and Savannah Sparrow, two

species associated with drier grassland habitat.

Figure 8. Avian indices along Yellow Creek comparing the proposed Feather River CRM-PG&E restoration

reach with Forest Service land upstream in 2008 and 2009. Error bars are 95% confidence intervals. Note no

meadow bird focal species were detected in the proposed project area in either year.

Pine Creek Valley Grassland Grazing Exclosure

At the Pine Creek Valley site, species richness was slightly higher outside of the grazing

exclosure and total bird abundance was greater inside the exclosure, although neither of these

differences was statistically significant (Figure 10). Only the abundance of Willet and Brewer’s

Blackbird – more abundant outside the exclosure - and Savannah Sparrow – more abundant

inside the exclosure - were statistically significant. Wilson’s Phalarope were more than four

0123456789

10

Species Richness


Focal Richness

Yellow Warbler

Song Sparrow

Warbling Vireo


Wilson's Warbler


Project Area

Upstream


60

times more abundant inside of the exclosure than outside though due to the relatively limited

sample size (n=15) this difference was not quite statistically significant.

Figure 10. Species richness, total bird abundance, and an index of the abundance of five species per point count station in the Pine Creek Valley grassland within and outside of a grazing exclosure in 2009. Error bars represent the 95% confidence interval.

Last Chance Creek Restored vs. Unrestored

I compared species richness, focal species richness, total bird abundance, and focal

species abundance at restored and untreated sites in the Last Chance Creek watershed in 2009.

Along the Alkali Flat transect, eleven point count stations were within areas that have been

treated while five points fell within treated areas on the Clark’s Creek transect. Seven of the

restored sites at Alkali Flat were restored in 2003 with the remaining three restored in 2007. All

five of the restored points at Clark’s Creek were restored in 2001. All four metrics were higher at

untreated sites along the Alkali Flat transect, with species richness, focal species richness, and

focal abundance significantly so (Figure 9). For Clark’s Creek, species richness, focal species

richness, and focal species abundance were all higher at untreated sites while total bird

abundance was higher at treated sites. Only focal species richness and abundance were

significantly different between restored and un-restored points at Clark’s Creek in 2009. When

all sites in the watershed were combined - including the 18 untreated points along the Lower Last

Chance Creek transect - focal species richness and abundance were significantly higher at

untreated sites. Species richness was higher at untreated sites while total bird abundance was

higher at treated sites but these differences were not significant.

Pine Creek Valley

0

1

2

3

4

5

6

SpeciesRichness

Total BirdAbundance

Brewer'sBlackbird

Red-wingedBlackbird

SavannahSparrow

Willet Wilson'sPhalarope

No GrazingGrazing


61

Figure 9. Per point species richness, total bird abundance, meadow focal species richness and meadow focal species abundance at restored and un-restored point count stations at Alkali Flat, Clark’s Creek, and all sites combined in the Last Chance Creek watershed in 2009 with 95% confidence intervals.

Alkali Flat

0123456789

Species Richness Focal SpeciesRichness

Total BirdAbundance

Focal SpeciesAbundance

# pe

r Poi

nt

TreatedUntreated

Clark's Creek

0123456789

10

Species Richness Focal SpeciesRichness

Total BirdAbundance


# pe

r Poi

nt

TreatedUntreated

Last Chance Watershed Total

0

1

2

3

4

5

6

7

8

SpeciesRichness

Focal SpeciesRichness

Total BirdAbundance


# pe

r Poi

nt

TreatedUntreated


62

Post-breeding Meadow Use

During the 2009 breeding season, we continued bird banding at the Gurnsey Creek mist-

net station, the 13th consecutive year this site has been monitored (Appendix A). Single visit

post-breeding mist-netting also continued at four meadows in the ARD: Hay, Swain, Spenser,

and Carter. Capture rates at these meadows in 2009 were very high with between 3.21 – 5.97

captures per net hour compared to 1.15 captures per net hour, the breeding season average at

Gurnsey Creek suggesting a relatively good productivity year for a number of species in the area.

Discussion

Wet meadows with extensive riparian deciduous vegetation support rich and abundant

breeding bird populations and are used extensively following the breeding season by the majority

of upland breeding species in the Sierra. Since wet meadows represent less than 1% of National

Forest land in the Sierra Nevada, and have been heavily degraded over the past century, meadow

restoration and conservation should be among the highest priorities of land mangers in the Sierra

Nevada. As meadows are arguably the single most important habitat for birds in the Sierra

Nevada (Siegel and DeSante 1999), and birds are a cost-effective tool to help guide ecological

restoration, avian monitoring and the management recommendations generated from it should be

seen as a integral tool to achieving meadow restoration in the Sierra Nevada.

The ARD area meadows support higher bird abundance than any other habitat type in the

Lassen region we have surveyed. Only aspen habitat (see Chapter 2) has slightly higher species

richness. Meadows in the greater ARD area are among the most important for meadow birds in

the Sierra Nevada. Yellow Warbler, a California Bird Species of special concern, reaches its

greatest reported density in the state here (RHJV 2004, Heath 2008). The area also harbors more

Willow Flycatcher than any other similarly sized area of the Sierra Nevada as well as a breeding

population of the state threatened Greater Sandhill Crane. With a wealth of mountain meadows

and many in a degraded state, the Feather River watershed should be considered an ideal location

to focus restoration actions to benefit these and other meadow dependent bird species.

Though many of our meadows sites, especially in the ARD, support relatively diverse

and abundant bird populations, it appears that many meadow sites (including a number we

surveyed) could benefit from some additional restoration actions. For many of the sites

(Robber’s Creek, Gurnsey Creek, Soldier Meadow), removal of encroaching conifers and


63

planting of willows could ensure the long-term health of these sites. Both Humbug Valley and

Yellow Creek have sections of stream channel that have been isolated from their floodplains and

may benefit from more significant restoration actions that restore a wet meadow condition. An

increase in riparian deciduous vegetation (e.g. Salix, Populus, and Alnus spp.) at many of these

sites would greatly enhance their value to meadow birds (e.g. Soldier Meadow, Last Chance

Creek restored sites).

There is currently little habitat value for wet meadow bird species within the Yellow

Creek proposed project area. In fact, the site had the lowest avian indices of any meadow site we

surveyed in 2009. In contrast, the 2 kilometers of meadow upstream from the project area

support a diverse and abundant meadow bird community, including recent detections of

Swainson’s Thrush and Willow Flycatcher – the two rarest meadow birds in the Sierra Nevada.

Additionally, this area supports an abundant population of Yellow Warbler, a California Bird

Species of Special Concern (Shuford and Gardali 2008). On Humbug Creek, 1 kilometer across

the valley from the project area, there are approximately eight Willow Flycatcher territories as

well as a large number of Yellow Warbler territories. Restoring Yellow Creek within the

proposed project area to a wet meadow with a substantial willow component is likely to have

substantial benefits to all of these meadow species of conservation interest as well as a host of

other meadow dependent focal species.

Unlike Yellow Creek, unrestored areas within the Last Chance Creek watershed do

support populations of several meadow focal species, especially Song Sparrow and Yellow

Warbler. Interestingly, we found that most avian metrics were higher at unrestored sites than

restored sites in the watershed in 2009. The higher total bird abundance at restored sites is

primarily due to Red-winged Blackbird being 28 time more abundant at restored sites, the

species that has clearly benefited the most from restoration actions thus far. Since we do not have

pre-treatment data for the areas that have been restored, it is difficult to determine how

restoration has affected the rest of the avian community at these sites. However, with some of the

lowest avian indices of any meadow sites we surveyed in 2009 and the fact that restored sites

have lower indices than unrestored sites, it appears that additional restoration actions (e.g. willow

planting) should be considered at restored sites to improve habitat for wet meadow dependent

birds. Where appropriate conditions exist to support riparian deciduous shrubs and trees, creating

dense clumps of these plants should improve habitat for meadow birds. Existing willow clumps


64

within the watershed that support Yellow Warbler and Song Sparrow could be used as a template

for creating suitable habitat in restored meadow areas. Alkali Flat sites 1-4 and Clark’s Creek

sites 10 and 11 had the highest density of these two species on these two transects. Additional

considerations during the design phase of restoration projects may also help improve habitat for

meadow birds in the first 10 years after restoration.

The Pine Creek Valley grassland is a distinctly different meadow than most of the sites

we have surveyed. Indeed it is more of a wetland with ponded water in many years well into

June with an undefined stream channel. Thus, the habitat is more suitable for bird species such as

waterfowl, shorebirds, and Sandhill Crane. We documented relatively large numbers of both

Wilson’s Phalarope and Willet at this site, both of which we believe breed here based on timing

of their occupancy and behaviors. Additionally, a pair of Sandhill Crane was observed on both

visits within and outside of the grazing exclosure. A complete list of species and their breeding

status is presented in Appendix B. In 2009 the majority of the wetland area we surveyed in Pine

Creek was inundated with water and therefore not actively being grazed by cattle. Thus, the

differences in habitat inside and outside of the grazing exclosure did not appear great. However,

we did find that Wilson’s Phalarope, Savannah Sparrow, and Red-winged Blackbirds were all

substantially more abundant inside of the exclosure while Willet and Brewer’s Blackbird were

more abundant outside of the exclosure. The Willets were primarily associated with the small

hummocks that provided upland islands within the flooded wetland. This feature was unique to

the area outside of the exclosure and may explain why the majority of Willet were found outside

of the exclosure and species richness was higher here.

A priority for meadow bird conservation in the Feather River watershed should be

protecting and enhancing the largest wet meadows, especially for Sandhill Crane, Willow

Flycatcher, and Yellow Warbler. However, our results also show that species such as Lincoln’s

Sparrow, Wilson’s Warbler, and Warbling Vireo are much more abundant in smaller and higher

elevation meadows, such as Carter. Several other higher elevation meadow sites such as

Robber’s Creek, Hay Meadow, and Spenser Meadow (where we have conducted post-breeding

banding), also support breeding Lincoln’s Sparrow. Thus, we recommend managing the larger

meadow complexes at lower elevations (3500 – 5500 feet) for species such as Sandhill Crane,

Willow Flycatcher, and Yellow Warbler (Childs Meadow, Battle Creek Meadow, Deer Creek

Meadow, Humbug Valley, West Shore Lake Almanor) while also protecting and, where


65

necessary, enhancing higher elevation sites to support species such as Lincoln’s Sparrow and

Wilson’s Warbler as well as provide critical post-breeding habitat for the majority of migratory

birds that breed in the Sierra Nevada. Additionally, wetland habitats which generally support far

lower abundance and diversity of meadow birds are important as they provide unique habitat for

uncommon species such as Sandhill Crane, shorebirds, and waterfowl.

Conclusions With the loss and degradation of riparian meadow habitat and it disproportionate

importance to birds, restoration and prudent management of meadows in the Feather River

watershed should be among the highest priorities of land mangers here. Increasing the function

and resiliency of wet willow-filled meadows should result in improved meadow bird habitat;

however, active measures such as willow planting is likely necessary to ensure habitat is

provided sooner rather than later. Meadow restoration in the Feather River watershed requires

partnerships between the U.S. Forest Service, local government agencies (e.g. Feather River

Coordinated Resource Management Group.), and non-profit organizations (e.g. The Nature

Conservancy, Feather River Land Trust, PRBO Conservation Science). Working together these

groups have the potential to dramatically increase the value of meadow habitats for birds in this

region.

Acknowledgements Funding for our meadow bird project is provided through Lassen National Forest wildlife

monitoring funds and a grant from the Resources Legacy Family Foundation. I wish to thank

Colin Dillingham and David Arsenault for their many hours of volunteering to collect all of the

bird data for the three Last Chance Creek transects. Additionally I would like to thank Tom

Frolli, Bobette Jones, Tom Rickman, and Mark Williams from the Lassen National forest and

Leslie Mink, Kara Rockett, and Jim Wilcox of the Feather River Coordinated Resource

Management Group for their assistance and support of this project.


66

Literature Cited Burnett, R. D., and D. L. Humple. 2003. Songbird monitoring in the Lassen National Forest: Results from the 2002 field season with summaries of 6 years of data (1997-2002). PRBO report to the U.S. Forest Service. Burnett, R.D., D.L. Humple, T. Gardali, and M. Rogner. 2005. Avian Monitoring in the Lassen National Forest. 2004 Annual Report. PRBO report to the U.S. Forest Service. Chase, M.K. and G.R. Geupel. 2005. The use of avian focal species for conservation planning in California. In Proceedings of the 3rd International Partners in Flight Conference. USDA Forest Service Gen. Tech. Rep. PSW-GTR-191. Heath, S.K. 2008. Yellow Warbler (Dendroica petechia) In Shuford, W.D. & T. Gardali (eds.), California Bird Species of Special Concern. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, CA and California Department of Fish and Game, Sacramento. Humple, D.L. and R.D. Burnett 2004. Songbird monitoring in Meadow and Shrub habitats within the Lassen National Forest: Results from the 2003 Field Season. A PRBO progress report to the USDA Forest Service. PRBO Contribution # 1173. Muir, J. 1911. My first summer in the Sierra. The Riverside Press, Cambridge, MA. Ralph, C.J., Droege, S., Sauer, J.R., 1995. Managing and monitoring birds using point counts: standards and applications. In: C. J. Ralph, J. R. Sauer and S. Droege (Eds.), Monitoring bird populations by point counts. USDA Forest Service, General Technical Report PSW-GTR 149, 161-169. Reynolds, R.T., J.M. Scott, and R.A. Nussbaum. 1980. A variable circular plot method for estimating bird numbers. Condor 82:309:313. RHJV (Riparian Habitat Joint Venture). 2004. Version 2.0. The riparian bird conservation plan: a strategy for reversing the decline of riparian associated birds in California. California Partners in Flight. http://www.prbo.org/calpif/pdfs/riparian.v2.pdf. Shuford, W.D., Gardali, T. (Eds.), 2008. California Bird Species of Special Concern. Studies of Western Birds No. 1. Western Field Ornithologists, Camarillo, CA and California Department of Fish and Game, Sacramento. Siegel, R.B. and D.F. DeSante. 1999. Version 1.0 The draft avian conservation plan for the Sierra Nevada Bioregion: conservation priorities and strategies for safeguarding Sierra bird populations. SNEP (Sierra Nevada Ecosystem Project) 1996. Sierra Nevada Ecosystems. Volume 1, chapter 1. Regents of the University of California. http://ceres.ca.gov/snep/pubs/web/PDF/v1_ch01.pdf


67

APPENDIX A. Summary of 2009 meadow mist-netting in the Almanor Ranger District with dates, net hours, captures, and capture rates. Site Date Net

Hours Captures Captures/

net hour Gurnsey Creek 5/20/2009 45 50 1.11Gurnsey Creek 5/30/2009 40 49 1.23Gurnsey Creek 6/9/2009 45 37 0.82Gurnsey Creek 6/20/2009 43.92 52 1.18Gurnsey Creek 6/27/2009 44.5 63 1.42Gurnsey Creek 7/9/2009 43.5 78 1.79Gurnsey Creek 7/17/2009 45 62 1.38Gurnsey Creek 7/29/2009 45 33 0.73Gurnsey Creek 8/5/2009 45 58 1.29Gurnsey Creek 8/17/2009 45 21 0.47Gurnsey Creek Total (Summer)

441.92 503 1.14

Gurnsey Creek 8/24/2009 44.5 35 0.79Gurnsey Creek 9/1/2009 45 31 0.69Gurnsey Creek 9/8/2009 45 27 0.60Gurnsey Creek 9/15/2009 45 30 0.67Gurnsey Creek 9/22/2009 45 64 1.42Gurnsey Creek 9/28/2009 42 123 2.93Gurnsey Creek Total (Fall) 266.5 310 1.16Hay Meadow 7/30/2009 36 215 5.97Swain Meadow 7/31/2009 36 209 5.81Carter Meadow 8/3/2009 33 166 5.03Spenser Meadow 8/4/2009 34 109 3.21


68

APPENDIX B. Breeding status of all bird species detected during two visits to the Pine Creek Valley wetland in 2009. Breeding status codes: 1 = confirmed breeder, 2 = likely breeder, 3 = no suitable nesting habitat within the wetland for this species probably just foraging here. Common Name Scientific Name Breeding Status American Robin Turdus migratorius 3 Barn Swallow Hirundo rustica 1 Brewer's Blackbird Euphagus cyanocephalus 2 Brewer's Sparrow Spizella breweri 2 Cliff Swallow Petrochelidon pyrrhonota 1 Common Raven Corvus corax 3 Horned Lark Eremophila alpestris 2 Killdeer Charadrius vociferus 2 Mallard Anus mallardi 2 Mountain Bluebird Sialia currucoides 2 Mourning Dove Zenaida macroura 2 Northern Pintail Anas aculta 2 Northern Shoveler Anas clypeata 2 Red-winged Blackbird Agelaius phoeniceus 1 Sandhill Crane Grus canadensis 2 Savannah Sparrow Passerculus sandwichensis 2 Spotted Sandpiper Actitis macularia 2 Vesper Sparrow Pooecetes gramineus 2 Western Meadowlark Sturnella neglecta 2 Willet Catoptrophorus semipalmatus 2 Wilson's Phalarope Phalaropus tricolor 1 Yellow-headed Blackbird Xanthocephalus xanthocephalus 2

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