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4/12/2011
1
Florida ScrubAn Ancient Endangered Ecosystem
Following glacial stages, polar ice‐caps melted, waters rose, and a series of ridges stood as islands in a vast ocean that covered most of Florida. Isolated from their distant relatives, plants and animals existing on these ridges evolved unique characteristics.
Lake Worth Subsea 0.15‐0.07 Ma Petuch and Roberts 2007
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Time, isolation, and harsh conditions resulted in a large number of species endemic to Florida Scrubs
Xeric oak scrub has a characteristic structure
LOW AND OPEN
• Dominated by oak shrubs less than 2 m tall
• Few if any trees
• Bare sandy patches throughoutthroughout
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Lightning‐ignited fire is the natural processby which scrub is maintained as low and open
Florida is North America’s hot spot for lightning
Oak scrubs probably burned at intervals of 5‐25 yearsand many plants and animals adapted to that frequency of fire
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In the absence of fire, xeric oak scrub succeedsinto sand pine forest or xeric oak hammock
•• Structural characteristics changeStructural characteristics change
•• Behavioral adaptations of Behavioral adaptations of endemic endemic species species become less become less effectiveeffective
•• Survival and reproduction Survival and reproduction decreasedecreasedecreasedecrease
•• Populations begin to declinePopulations begin to decline
Chronological response of FSJ populations to fire
Relative
Qua
lity
Optimal
tat
ure
Dispersers
Jay
Dispe
rsal
RefugeesRefugees
X X
0 1 2 3 4 5 6 ………… 10 15 20 30 40
Hab
itStruct
Years Since Fire Fitzpatrick, Woolfenden and Bowman 1999
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5
es6
7
Chronological response of FSJ populations to fire
Scru
b-Ja
y Te
rrito
ri
2
3
4
5
16‐17 years
Year
1980 1985 1990 1995 2000 2005 2010
#
0
1FIRE FIRE
Ecological changes with urbanization?
• Natural habitat
•• Frequent fire regimeFrequent fire regime
• Suburban habitat
•• Fire interval lengthenedFire interval lengthenedFrequent fire regimeFrequent fire regime
•• Mosaic of natural habitatsMosaic of natural habitats
Fire interval lengthenedFire interval lengthened
•• Habitat fragmentation and Habitat fragmentation and perforationperforation
•• Increased edge with nonIncreased edge with non‐‐native native habitats, roadshabitats, roads
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Increasingly, humanIncreasingly, human‐‐induced changes to the induced changes to the landscapes that surround our protected lands are landscapes that surround our protected lands are affecting our ability to manage affecting our ability to manage them, and Jays to them, and Jays to survive in them.survive in them.
Malabar Scrub PreserveBrevard County
Florida is a State of fire, we (the public) need to be aware that this is natural and needed disturbance
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A good maintenance A good maintenance burn will not be 100%burn will not be 100%Allows for Allows for potential refugepotential refugeSome nest sites still Some nest sites still remainremain
Optimal burning strategy for FSJs in suitable habitat
Immigration
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E t h bit t i li tE t h bit t i li t
The Florida Scrub‐Jay’s Dilemma
• • Extreme habitat specialistExtreme habitat specialistEvergreen oak scrub on xeric soilsEvergreen oak scrub on xeric soilsPatches sharply definedPatches sharply defined
• • FireFire‐‐maintained habitat, much is degradedmaintained habitat, much is degraded• • Only fragments remain, small and isolatedOnly fragments remain, small and isolated
Limited dispersal abilityLimited dispersal abilityp yp y• • Scale of ecological processes impeded by Scale of ecological processes impeded by anthropogenic anthropogenic boundariesboundaries
Independent of habitat quality,Independent of habitat quality,Population persistence depends on size and isolationPopulation persistence depends on size and isolation
But if these populations occur within a network of connected reserves, these extinction risks
b t ti ll llare substantially smaller
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• Declines first observed early in the 20th century (Byrd
The plight of the Florida ScrubThe plight of the Florida Scrub‐‐Jay has been Jay has been recognized since the early 1930’srecognized since the early 1930’s
1927, Grimes 1940)
• Declining populations commented on continually throughout the last century (Grimes 1943; Early 1952; Longstreet 1954; Sprunt1946; Brigham 1973; Austin 1976, Woolfenden1978a; Cruickshank 1980; Cox 1987; Fitzpatrick et al 1991; Fitzpatrick et al 1994; Stith 1996).
• In 1992‐1993, the first and most comprehensive effort to survey the entire range of the Florida Scrub‐Jay was undertaken
Merritt Island
Ocala NF??
• As of 1992‐1993 ~ 4000 family groups
• ~25‐50% decline since 1980
• ~21 potentially viable t l ti (>10 )
Lake Wales Ridge
metapopulations (>10 groups)
• 3 largest mostly on public lands
• Extirpated from 10 of 39 counties of observed range
•• Overall, considerable Overall, considerable evidence suggested a 90evidence suggested a 90evidence suggested a 90evidence suggested a 90‐‐95% population decline 95% population decline since presince pre‐‐European European settlement numberssettlement numbers
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Despite increasing numbers of localized extirpations and declines, no comprehensive effort had been conducted to estimate impacts and managed lands acquisition success upon this Federally Threatened species, since 1992.
1. Collect and collate existing FSJ survey data
2. Conduct surveys where those data are not available
3. Quantify current numbers of FSJs on managed lands
4. Compare those numbers to the 1992‐1993 survey
5 Estimate population trends for all sites5. Estimate population trends for all sites
6. Estimate the habitat carrying capacity for FSJs
Acquisition alone is not enough to protect this
listed species
47 sites increase
95 sites decline
37 No change
Results
Between 1992‐1993 and 2009‐2010, FSJs declined at 54% of public lands where data were available (179 of 198 sites), largely because of a lack of effective management.
What was the distribution What was the distribution of these declines and of these declines and increases?increases?
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400
500
9‐2010
(%)
0
100
200
300
hange in Pop
ulation by
2009
‐100
1 10 100 1000
Ch
1992‐1993 Population Size (Breeding Pairs)
Many small populations went extinct
80
90
20
30
40
50
60
70
Freq
uency 1992‐93
2009‐10
0
10
0 1 5 10 20 40 50 100 More
Managed Population Size
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12
Size distribution of 1992‐1993 managed populations now extinct
30
35
10
15
20
25
Freq
uency
0
5
1 2 3 4 5 6 7 8 9 10 21
Population Size (Breeding Pairs)
Highlands County
L k W lLake Wales Ridge
CaseStudy
L a k eL a k eI s t o k p o g aI s t o k p o g a
StudyH i g h l a n d s C o u n t yH i g h l a n d s C o u n t yL a k e W a l e s R i d g eL a k e W a l e s R i d g e
D i g i t a l E l e v a t i o n M o d e lD i g i t a l E l e v a t i o n M o d e l~~
U N I T E D S T A T E S G E O L O G I C A L S U R V E YU N I T E D S T A T E S G E O L O G I C A L S U R V E YU S G S M a p p i n g A p p l i c a t i o n s C e n t e rU S G S M a p p i n g A p p l i c a t i o n s C e n t e rN a t i o n a l C a r t o g r a p h i c I n f o C e n t e rN a t i o n a l C a r t o g r a p h i c I n f o C e n t e r
5 0 7 N a t i o n a l C e n t e r5 0 7 N a t i o n a l C e n t e rR e s t o n V A 2 2 0 9 2R e s t o n V A 2 2 0 9 2
~~0 2 4 6 8 10
Kilometers
This map was created at the Archbold Biological StationGeographic Information System Laboratory
Prepared by: Roberta L. Pickert 19 March 2002¬
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Wildlandsnatural
ecological processes
Urban Perforated
Urban Matrix Extensive
development
Perforatedpotential for conservation
Agricultural previous
disturbance
0-75-50-25
0255075
100
0-75-50-25
0255075
100
-100-100
255075
100
255075
100
Natural/protectedNatural/protected Urban reclaimedUrban reclaimed1992 2009 %∆ 1992 2009 %∆
-100-75-50-25
0
-100-75-50-25
0
UrbanUrban AgriculturalAgricultural
1992 2009 %∆1992 2009 %∆
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• ~4000 pair total Florida Scrub‐Jay population 1992‐1993• ~1500 pair in managed lands 1992‐1993; 1161 pair in 2009‐
2010 (22% decline)
• ~2500 pair outside of managed lands 1992‐1993.
Declines possibly somewhere between 50‐75%
@ 50% Total Population Florida Scrub‐Jays
= 1161 + 2500x0.50
= 2411 groups! ~7000 birds
@75% Total Population Florida Scrub‐Jays
= 1161 +2500x0.75
= 1786 groups!! ~5400 birds
But what does the future hold for managers?
1. Collect and collate existing FSJ survey data
2. Conduct surveys where those data are not available
3. Quantify current numbers of FSJs on managed lands
4. Compare those numbers to the 1992‐1993 survey
5. Estimate population trends for all sites
6 E ti t th h bit t i it f FSJ6. Estimate the habitat carrying capacity for FSJs
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Scrub habitats compiled from a variety of sources;
• 1992‐1993 Habitat Mapping
Oak Hickory Scrub
Scrub
Scrubby Flatwoods
LWRWEALake Placid Scrub
• Florida Natural Areas Inventory – natural communities updates
• Soil SurveysArchbold Biological
Station
LWRWEAMcJunkin
Tract
• Aerial imagery – high resolution 2007‐2009
• Used to calculate carrying capacity
LWRWEA Gould Road
22 % overall decline since 1992‐1993 in managed landsCurrently at 37% of a moderate carrying capacity (70%)
3000
3500
rs)
1500
2000
2500
ion Size (B
reed
ing Pair
0
500
1000
70% Car 1992‐93 2009‐10
Popu
lati
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16
175
200
225
250
grou
ps)
50
75
100
125
150Cu
rren
t Pop
ulation (# g
0
25
0 25 50 75 100 125 150 175 200 225 250
70% Carrying Capacity (# groups)
35
40
45
50
grou
ps)
10
15
20
25
30
Curren
t Pop
ulation (# g
0
5
10
0 5 10 15 20 25 30 35 40 45 50
70% Carrying Capacity (# groups)
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Management Does Work
roup
s10
20
shiftsan
ge in
num
ber o
f bre
edin
g gr
-20
-10
0
1993 93 to 2009 10
32
7 810
23
6
7 92
8
4 63
35 9 6 0 8 17 45 1327 7
0 2 141 6 1
1 0 0 3
UnmanagedManaged
isolated
FSJ population trends on the LWR WEA
Cha
-40
-30 1993-93 to 2009-1032
megaparcels
Management will be most effective in intact landscapes
Florida ScrubFlorida Scrub‐‐jay jay ‐‐ Island BiogeographyIsland Biogeography
Need at least 10 Territories, within short distance dispersal, larger is better
Dispersal occurs along appropriate habitats. High urban, tall forest, large grasslands with no bushes are impermeable to FSJs
These patches need to be within at least 3.5 km? for reasonable colonization rates to occur
Stith 1996 Metapopulation Dynamics
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R i iRemaining ScrubsHighlandsCounty
C ti itConnectivity for FSJs 3.2km
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P l tiPopulation splinters increasing probability of extinction
Can we conserve the Florida Scrub‐Jay?
Ultimately survival of species in our now human‐dominated system depends on human attitudes and behaviors
As Conservationistss Co se at o sts
• Focus on regional meta‐populations and how your site fits into the overall picture
• Identify managed sites with greatest probability of self
t i i l ti dsustaining populations and immediately improve habitat.
• Work outwards from these successful core populations, adding to them, and linking them to satellite populations
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Funding and Support
NSF ‐ Research Coordination Network: Ecological ImmunologyNSF Research Coordination Network: Ecological ImmunologyNSF ‐ SGER for epizootic in 2008NSF ‐ Doctoral Dissertation Improvement Grant IBN‐0508418
Sigma Xi – Grants in Aid of Research
SICB – Grants in Aid of Research
U of M ‐ Faculty/Student Collaborative Research Travel Grant
U of M ‐ Student Government Association Travel Award
American Ornithologists Union
Marcia Brady Tucker Travel Award Archbold Biological StationField and Lab Support