Fork-tailed storm-petrel monitoring at East Amatuli Island ...AMNWR 2014/10 FORK-TAILED STORM-PETREL MONITORING AT EAST AMATULI ISLAND, ALASKA DURING 1997-2013 Arthur B. Kettle Key

AMNWR 2014/10

FORK-TAILED STORM-PETREL MONITORING AT

EAST AMATULI ISLAND, ALASKA DURING 1997-2013

Arthur B. Kettle

Key words: Alaska, nesting date, Barren Islands, East Amatuli Island, food habits, fork-tailed storm-petrel,

growth rate, Oceanodroma furcata, populations, productivity, reproductive success

U.S. Fish and Wildlife Service

Alaska Maritime National Wildlife Refuge

95 Sterling Highway, Suite 1

Homer, AK 99603

December 2014

Cite as: Kettle, A. B. 2014. Fork-tailed storm-petrel monitoring at East Amatuli Island, Alaska during 1997-

2013. U.S. Fish and Wildlife Service Report, AMNWR 2014/10. Homer, Alaska.

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TABLE OF CONTENTS Page

INTRODUCTION ........................................................................................................................................... 1 STUDY AREA ............................................................................................................................................... 1 METHODS .................................................................................................................................................... 2

Nesting date ............................................................................................................................................ 2 Reproductive performance ..................................................................................................................... 3 Chick growth rate .................................................................................................................................... 3 Population trend...................................................................................................................................... 4 Chick diet ................................................................................................................................................ 4 Comparison among petrel indices .......................................................................................................... 4 Comparison of annual petrel indices with monthly environmental indices ............................................. 4

RESULTS and DISCUSSION ....................................................................................................................... 5 Nesting date ............................................................................................................................................ 5 Reproductive performance ..................................................................................................................... 6 Chick growth rate .................................................................................................................................... 6 Population trend...................................................................................................................................... 6 Chick diet ................................................................................................................................................ 6 Comparison among petrel indices .......................................................................................................... 6 Comparison of annual petrel indices with monthly environmental indices ............................................. 7

ACKNOWLEDGMENTS .............................................................................................................................. 10 REFERENCES ............................................................................................................................................ 10 FIGURES AND TABLES ............................................................................................................................. 12

Island maps .......................................................................................................................................... 13 Nesting date .......................................................................................................................................... 17 Reproductive performance ................................................................................................................... 22 Chick growth ......................................................................................................................................... 41 Population trend.................................................................................................................................... 45 Chick diet .............................................................................................................................................. 47

APPENDICES ............................................................................................................................................. 49

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INTRODUCTION

The Alaska Maritime National Wildlife Refuge (AMNWR) conducts annual ecological monitoring at nine

sites throughout Alaska (Figure 1). The objective of this long-term monitoring program is to collect

baseline status and trend information for a suite of seabird species representing piscivorous and

planktivorous trophic guilds, including key species that serve as indicators of ecosystem health. Members

of these guilds include surface-feeders and divers, feeding in both nearshore and offshore waters. By

comparing the data with environmental conditions and information from other sites, ecosystem processes

may be better understood. Data also provide a basis for directing management and research actions, and

in assessing effects of management.

East Amatuli Island, in the Barren Islands group, has been a refuge-funded annual monitoring site since

2000 (except in 2012, when due to a Refuge budget reduction, monitoring at East Amatuli did not occur;

Kettle 2013, 2014).

One key monitoring species for the East Amatuli monitoring site is the fork-tailed storm-petrel

(Oceanodroma furcata). This species was included in the first biological reconnaissance of the Barren

Islands, conducted by Edgar Bailey of the U. S. Fish and Wildlife Service during 1974-1975 (Bailey 1976).

The species was studied at East Amatuli by University of Washington personnel for various seasonal

periods during 1976-1994 (Boersma and Wheelwright 1979(a), Boersma and Wheelwright 1979(b),

Boersma et al. 1980, Manuwal 1980, Simons 1981, Boersma 1982, Boersma 1986, Boersma and Parrish

1996, Boersma and Parrish 1998). The refuge monitored storm-petrels at East Amatuli during 1-2-week

trips made once or twice each summer to monitor mainly burrow-nesting species during 1985-1989

(Nishimoto et al. 1986, Nishimoto et al. 1987, Nishimoto and Beringer 1988, Nishimoto and O’Reilly 1989,

Nishimoto 1990). Storm-petrels were included in Refuge work during 1993-1999, when selected seabird

species at East Amatuli were monitored annually for oil spill damage assessment and recovery by the

refuge with funding from the Exxon Valdez Oil Spill Trustee Council (Roseneau et al. 1995, 2000).

Plots and methods established by refuge personnel in 1997 and 1998 for monitoring fork-tailed storm-

petrel productivity, chick growth rate, and population trend were used each year during 1997-2013

(except 2012, when no data were collected). This report describes methods and presents results of

storm-petrel monitoring during these years. These results were not directly and quantitatively comparable

with published and reported results of pre-1997 work. Results from previous work will be incorporated into

future reports and publications, where possible.

STUDY AREA

East Amatuli Island (5855' N, 15210' W) is one of the seven Barren Islands, located between the Kodiak

archipelago and the Kenai Peninsula (Figures 2, 3, and 4). The Barren Islands range in size from 10 to

2800 ha, totaling about 4000 ha. Geologically the islands are a continuation of the Kenai Peninsula and

are of mixed origin (from map by Wilson et al. 2009). They are generally steep and tall, ranging to an

elevation of 650 m. Among the eighteen species of seabirds that breed on the islands are about 75,000

pairs of fork-tailed storm-petrels (Oceanodroma furcata), 25,000 pairs of black-legged kittiwakes (Rissa

tridactyla), 3,400 pairs of glaucous-winged gulls (Larus glaucescens), 60,000 pairs of common murres

(Uria aalge), and 70,000 pairs of tufted puffins (Fratercula cirrhata; Manuwal 1980, Roseneau et al.

2000).

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Of the Barren Islands group East Amatuli contains the highest seabird abundance. The island provides

ledges physically suitable for cliff-nesting birds and contains substrate for burrow-nesters. While the North

American river otter (Lontra canadensis) is common across the island group, the group’s other

mammalian seabird predators, northern red-backed vole (Clethrionmys rutilus, present on West Amatuli

and Ushagat) and arctic ground squirrel (Spermophilus parryii, present on Ushagat) are absent from East

Amatuli.

Most of East Amatuli Island is comprised of steep slopes, with a spine ranging up to 470 m. Lower

elevations are dominated by grasses and sedges; higher elevations by crowberry (Empetrum nigrum) and

other maritime tundra plants.

High marine productivity around the Barren Islands contributes to the seabird breeding habitat. Steep

local bathymetry, the location at the entrance to Cook Inlet with its large tides and currents, the

surrounding Alaska Coastal Current, and the strong winds of the area are factors that make the Barren

Islands prolific for large numbers of breeding seabirds and marine mammals.

METHODS

We obtained information for fork-tailed storm-petrel nesting date, reproductive performance, chick growth,

and population trend from 11 rectangular plots established in the camp valley by AMNWR personnel

during 1997 and 1998. Ten of the plots are 20 x 10 m in size and one is 10 x 10 m. To help us search for

burrows we used a grid made from knotted Redden Marine #72 Gagnion Twine. This grid was stretched

between the four corner stakes of each plot to form 5 m x 5 m quadrats. We searched for burrows by

quadrat and using standardized codes recorded burrow contents. The first survey of all 11 plots occurred

in 1998. Parameters in this report that use all 11 plots exclude the year 1997.

Nesting date: In most years we did not continuously monitor eggs to determine their hatch dates. To

obtain an index for nesting date we instead calculated one from chick growth data (Figure 5; see “Chick

growth rate” below for field and analysis methods of that parameter).

For calculating the index we used wing growth rate rather than mass growth because wing growth better

fit a linear model. First we identified each chick’s first wing chord measurement between and including

Julian dates 230 and 240 (in a non-leap-year these dates are 18 and 28 August). We chose these dates

because they were about midway through the nestling period and included data from the greatest number

of monitoring years (see line charts of the data in Appendix 1).

Using that wing chord measurement, its date, and the linear slope of the chick’s wing growth rate, we

back-calculated the date when the chick would have had (by the linear model) a wing length of 20 mm.

We called this the “20-mm Date”. At this size a fork-tailed storm-petrel chick is just a few days old (from

Manuwal 1980). We back-calculated only to this length and not to the hatch date because 20 mm is

considered to be the start of the “linear phase” of growth—measurements shorter than 20 mm would be in

the early nonlinear phase. Growth during that nonlinear phase would be difficult to model; it is also

physically difficult in the field to measure such small wings accurately.

Our annual index of nesting date therefore was the among-chick mean 20-mm Date. For a measure of

dispersion we calculated one standard deviation among the chicks’ 20-mm Dates. We tested for

significant differences among years with ANOVA and the Tukey post-hoc test.

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Reproductive performance: We used five indices to measure fork-tailed storm-petrel productivity in the 11

plots each year:

1) The number of chicks found in all of the plots. Because in 2001 one plot was inadvertently missed, we

list both the sum for all 11 plots (except in 2001), and for just 10 plots (for all years). As a method for

comparing as much data as possible across years, we also list each year’s sum as a percent of the

among-year maximum sum for the year’s plot-set--for 2001 this number is the percent of the among-year

maximum of the 10 plots counted that year; for the other years it is the percent maximum of all 11 plots.

This “percent of maximum” is the common measure we used for charting the results.

2) The sum of chicks in all of the plots divided by the sum of burrows. We calculated this for each plot and

for all plots combined.

3) The sum of “large” chicks in all of the plots—those that had reached or exceeded a mass of 50 g by the

end of each field season--and this sum’s percentage of the maximum among years for that season’s plot-

set.

4) The sum of “large” chicks in all of the plots divided by the sum of burrows, for each plot and for all plots

combined.

5) As a proxy for fledging success we used the sum of “large” chicks at the end of the field season divided

by the sum of all chicks found during the season. In some of the plots the size of the divisor (the sample

of chicks) was insufficient for a meaningful ratio. For this reason, we grouped three sparse-chick plots

with adjacent plots before calculating by-plot (or by-group) “fledging success” ratios. We also calculated a

ratio for the sum among all the plots—this was our annual index for fledging success. For a measure of

dispersion for the index we used ratio estimation to calculate standard deviation. The ratio estimator used

variation among the plot values to obtain a standard deviation value for the overall ratio.

Not all chicks had fledged when we departed the island each year, but survival rate was high for chicks

that reached our “large” category lower limit of 50 g. Because survival rate is lower for small chicks, we

omitted from the “fledging success” calculations chicks with a mass of less than 50 g when we departed;

they were put into the “fate not known” category. Also in this category were chicks not measured because

we could not retrieve them from constricted rocky burrows.

Chick growth rate: Each year except 2000 (and 2012), we measured (to 1 mm with a wing ruler) the chord

length of the relaxed (not straightened) folded right wing of a sample of storm-petrel chicks every 5-7

days. The wing-ruler stop was placed against the outside of the carpal-metacarpal joint and we measured

to the wing-tip--whether it was bone, shaft, or primary feather (down feathers were excluded). We also

measured mass (to 1 g with a Pesola® 100- or 300-g spring scale).

Because increase in wing length was more linear than was increase in mass, mean daily change in wing

chord was our index for chick growth. We calculated a wing growth rate (to 0.1 mm d-1

) for each chick

with a linear model using data between 20 to 140 mm, inclusive (the “linear” range in AMNWR protocol).

We used only growth slopes with regression R-squared values ≥ 0.80 for the index. Our annual index was

the mean (reported to 0.01 mm d-1

) among rates.

We also report the linear mass gain (to 0.01 g d-1

), for masses between 0 to 80 g, inclusive (also a “linear”

range defined by AMNWR protocol). We used an R-squared limit of 0.80.

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For both wing growth and mass gain we limited our analysis to chicks with three or more measurements

within the “linear” range. We calculated standard deviation among growth slopes as an annual measure

of dispersion. As a gauge of the potential indices’ utility we used ANOVA and the Tukey post-hoc test to

analyze among-year differences in wing growth and mass gain.

To aid protocol evaluation we charted growth slopes calculated both with a minimum R-squared limit of

0.80 and without.

Population trend: We used as our annual index for population trend the total number of burrows found in

the 11 plots (10 in year 2001), expressed as a percentage of the among-year maximum number of

burrows counted in the year’s plot set (in 2001 it was the among-year maximum counted in the 10 plots

surveyed that year).

Chick diet: Adult fork-tailed storm-petrels sometimes regurgitate when handled. We utilized this defense

mechanism to collect diet samples in 2011 and 2013. On several nights during each of these seasons we

collected regurgitations from adults captured in a mistnet. We retained all samples that contained food

other than well-digested orange oil. These retained samples were likely to be loads destined for chicks.

We collected each regurgitation sample in a 4-oz plastic jar. The total number of collected samples in

2011 was 31; 15 of these were of sufficient size (>5 g, by protocol) for diet analysis. In 2013 we collected

46 samples; 22 were large enough for analysis.

Samples from 2011 were analyzed by Kathy Turco, Fairbanks, Alaska. Data were summarized by her as

the percentage of samples containing each prey type. Samples from 2013 have not yet been analyzed.

Comparison among petrel indices: To test which fork-tailed storm-petrel parameters were associated with

each other, Pearson correlation coefficients and P-values were calculated for each parameter pair.

Comparison of annual petrel indices with monthly environmental indices: Among-year fork-tailed storm-

petrel indices were compared with among-year monthly values of some environmental variables. A

Pearson correlation coefficient and P-value were calculated for each comparison. While in many cases

successive within-year monthly environmental values were autocorrelated, the approach here was

exploratory—to see whether environmental drivers were more influential during particular times of the

year than others--and was not meant to provide independent samples.

While food web processes affecting availability of prey for fork-tailed storm-petrels are little known (and

very little also is known about their foraging locations, especially in the winter), this exploratory approach

was used to try to discern patterns of association between the petrel monitoring data and environmental

conditions that may affect the prey availability and, in turn, breeding productivity.

Many prey species are sensitive to sea surface temperature (SST), and this is an environmental condition

with data readily available. For this report, both a local source of SST data and a broad-scale SST index

were used. SST is driven to some extent by atmospheric conditions such as trends in atmospheric

pressure; for this reason another index--one of pressure over the North Pacific--was used.

Also used for comparison were precipitation records, not as an indicator of food web processes but rather

of conditions at the burrow. It’s possible that spring snow depth affects timing of nesting, or that burrow

moisture levels through the summer affect the survival of eggs and/or chicks.

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For each environmental parameter, comparison with seabird data was first done with matched years.

Next, comparisons were made by lagging environmental data one year (by matching the petrel data with

the previous year’s environmental data); then for two years; and finally they were advanced one year (by

matching the petrel data with the next year’s environmental data). Data were lagged to see whether

environmental effects on breeding were delayed through food web, adult breeding condition, or other

processes. The advanced-year calculations were made with the idea that there shouldn’t be any

correlations in that direction, as a check on the role of chance in the procedure and results. The general

procedure of checking for lag effects was inspired by Zador et al. 2013.

The environmental indices used for comparison were:

1. Local sea surface temperature: Sea temperature anomaly was calculated from NOAA COOPS data

from the tide station at Seldovia, Alaska (55 km north of East Amatuli), for each month in the years 1996-

2013. Anomalies were also calculated for an adjacent sensor in Seldovia operated by the Kachemak Bay

Research Reserve (KBRR), as a component of the National Estuarine Research Reserve System’s

System-Wide Monitoring Program. This allowed replacement of seven months of apparently inaccurate

data and six months of missing data from the NOAA sensor. The NOAA sensor was used as the primary

data source because the KBRR sensor did not cover all of the years needed. Monthly SST anomaly at

Seldovia was highly correlated with other sea temperature records in the Gulf of Alaska (A. Kettle,

unpublished analysis).

2. Pacific Decadal Oscillation monthly index (this definition copied from http://jisao.washington.edu/pdo/):

“The Pacific Decadal Oscillation (PDO) Index is defined as the leading principal component of North

Pacific monthly sea surface temperature variability (poleward of 20N for the 1900-93 period).” Monthly

values were obtained from <http://jisao.washington.edu/pdo/PDO.latest>.

3. North Pacific Index (Trenberth and Hurrell 1994; Hurrell et al. 2014; this definition copied from

<https://climatedataguide.ucar.edu/climate-data/north-pacific-np-index-trenberth-and-hurrell-monthly-and-

winter>): “The North Pacific Index (NP index or NPI) is the area-weighted sea level pressure over the

region 30°N-65°N, 160°E-140°W. The NP index is defined to measure interannual to decadal variations in

the atmospheric circulation. The dominant atmosphere-ocean relation in the North Pacific is one where

atmospheric changes lead changes in sea surface temperatures by one to two months.” Monthly values

were obtained from:

<https://climatedataguide.ucar.edu/sites/default/files/climate_index_files/npindex_monthly_1.txt>

4. Precipitation. Precipitation anomaly was calculated from National Climate Data center data from the

airport at Kitoi Bay, Afognak Island, AK (80 km south of East Amatuli) for each month for the years 1996-

2013.

As a check of the likelihood of spurious results in this exploratory approach, analysis of the petrel

parameters and Seldovia SST was repeated, but with one change. This time the order of the year-groups

of petrel parameters were randomized (while the suite of petrel parameters remained grouped within each

year).

RESULTS and DISCUSSION

Nesting date: The calculated index “20-mm Date” varied significantly between years (Figure 6; Tables 1

and 2; ANOVA:F[14,258]=6.29,p<0.001; Tukey post-hoc results are in Appendix 2). Exhibiting the

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greatest number of significant differences with other years were the year with the latest date, 1998 (an El

Nino year when water warmed in the Northern Gulf of Alaska in late winter) and the years with the earliest

dates, 2002 and 2004.

Exploratory comparison with other AMNWR monitoring sites showed that results from the late and early

years, and the overall temporal pattern of 20-mm Date anomaly values through the study period, were

similar to results from Aiktak Island, AK (Pearson correlation r = 0.79, p<0.001, Figure in Appendix 3;

Howie et al. 2014).

Reproductive performance: The number of chicks and large chicks found in the plots generally increased

from 2000 to 2007 and then was lower during 2008-2013 (Figures 7 and 8; Tables 3-7). The indices

“Chicks-per-burrow” and “Large-chicks-per-burrow” followed the same pattern (Figures 9 and 10; Table

3)—which would be expected since the number of burrows found through the years was generally stable

(Figure17; Table 3). The years 1998 (an El Nino year) and 2000 had the lowest chick production.

Chick survival to “large” (>= 50 g) size was lowest in 2000 and 2001 (Figure 11; Table 3). In most years

the large-chicks to chicks ratio was above 0.70.

Chick growth rate: Mass growth and wing growth each varied significantly between years (Figures 12-15;

Table 8; ANOVA:mass:F[14,168]=6.29,p<0.001, wing:F[14,321]=12.11,p<0.001; Tukey post-hoc results

are in Appendices 4 and 5).

Mass growth did not fit a linear model as well as wing growth did (see Appendix 1). The sample of chicks

for mass growth was greatly reduced when a minimum R-squared filter of 0.8 was applied. Also, the

growth slope was generally higher with the filter (Figures 12 and 13).

Wing growth fit the linear model well. Slopes for most chicks had an R-squared value of 0.8 or higher

(Figures 14 and 15).

The Tukey post-hoc test showed between-year-pair significant differences more frequently and at lower

probability values for wing growth than for mass gain (Appendices 4 and 5).

Annual indices for wing growth and mass growth were not significantly correlated with each other (Figure

16; Appendix 6). That is, in a year when a year’s wing growth index was low, the mass gain index didn’t

tend to be either high or low.

Population trend: In the plots the number of burrows was relatively stable over the 1998-2013 period

(Figure 17; Table 9).

Chick diet: Amphipods, euphausiids (krill), and fish were the types of prey found most commonly in the

chick diet samples from 2011 (Table 10). Of the total number of prey items, euphausiids were the most

numerous, followed by amphipods and fish (Table 11).

Comparison among petrel indices: Correlation analysis among the petrel monitoring indices showed (see

Appendix 6) that:

1. Years of earlier 20-mm Dates were significantly correlated with years of higher numbers of large

chicks.

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2. Years with more chicks were significantly correlated with years of more large chicks and of higher

fledging success.

3. Years with more large chicks were significantly correlated with years of earlier 20-mm Dates, of more

chicks, of higher fledging success, and of faster wing growth.

4. Years with higher fledging success were significantly correlated with years of more chicks, of more

large chicks, and of faster wing growth.

Comparison of annual petrel indices with monthly environmental indices:

Comparison of the petrel parameters with current and lagged local SST, NP index, PDO index,

precipitation, and other environmental variables is preliminary in this report and will continue by the author

after this report is issued.

Caveats:

The procedure and presentation method here was exploratory.

There is monthly autocorrelation in some of the environmental variables presented here. For example,

warm SST one month tended to carry over to the next month, or for several months. Therefore, when a

petrel annual index value shows correlation with successive months’ SST values, the successive results

should not be considered independent.

Similarly, the variables themselves should not be considered independent. As shown above, several of

the petrel parameters are related to each other, as are the environmental variables: local SST, ocean-

scale SST, atmospheric pressure, and precipitation.

Given the large number of correlations done in this analysis, some results that show significant correlation

between seabird parameters and environmental anomalies may be spurious.

Matched-years correlation tables:

One fairly consistent result in the matched-year tables is that three March environmental variables were

significantly correlated with petrel parameters:

1. Higher March local SST was correlated with lower counts of chicks, lower counts of large chicks, and

lower fledging success (Appendix 7; these three petrel parameters are related to each other, of course.)

2. Higher March NP index was correlated with earlier 20-mm Dates and higher counts of chicks and large

chicks (Appendix 9). Since higher NP index is associated with colder coastal Alaska SST (Appendix 13);

this result agrees with result (1).

3. Higher March precipitation at Kitoi Bay was correlated with lower counts of chicks and large chicks,

lower fledging success, and lower wing growth rate (Appendix 10). (However, a separate test showed that

the precipitation and SST variables were themselves significantly correlated for March).

Lagged- (and advanced-) years correlation tables:

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1. For local SST there were more significant lagged-year than matched-year results (Appendix 7).

2. When the petrel data were lagged one year, higher local SST was positively correlated every month

during January-October with earlier nesting (four months significantly), higher chick count (one month

significantly), and higher large-chick count (six months significantly; Appendix 7).

3. When the petrel data were lagged two years, local SST was negatively correlated with the number of

burrows every month during January-August--seven months significantly (Appendix 7). PDO was

negatively correlated with burrow counts when petrel data were lagged one year (January-October; May,

July, and August significantly) and two years (every month; January-May and July significantly; Appendix

8).

4. When the petrel data were advanced one year (for example, 2012 petrel data were paired with the next

year’s [2013’s] environmental correlates), both local SST and PDO were positively correlated with earlier

nesting during every month--six months significantly for local SST and seven months for PDO

(Appendices 7 and 8).

5. Some results for the PDO and NP indices followed their association with coastal SST; others did not

(Appendices 7-9).

Discussion:

Without more information about storm-petrel winter and spring foraging areas, foraging behavior, and

diet, there is abundant opportunity for conjecture about causes of significant correlations between

environmental conditions and the lagged (and advanced) petrel breeding season data.

One possibility is that the prey base is lagged in time from sea temperature changes. For example, if

petrel prey takes a year to develop/grow, then a change in sea temperature that affects survival/growth of

the prey during the first year may be reflected in the breeding season prey base not until the following

year.

Another possibility is that foraging conditions during the year previous to nesting is more important than

conditions while nesting. That is, birds may need to build energy reserves a year in advance of breeding.

If so, a year of good foraging conditions may be reflected by higher reproductive success not until the

following year.

For example, for the lagged-2-years petrel parameters, higher Seldovia SST in December was correlated

with earlier 20-mm Dates, higher counts of chicks and large chicks, higher fledging success, and faster

wing growth. This is for the December 1.5 yr before the monitoring season when the petrel parameters

were measured. Same-sign significant results for 20-mm Date and large chicks (and fairly high

correlation values all of the same sign for chicks) continued into subsequent months (on the lag-1-year

table).

Perhaps the birds begin to gain condition for a breeding season 1.5 yr in advance. Perhaps they

sometimes--or always--don’t breed every season.

As for why for in this previous, pre-breeding year the correlation between local SST and chick counts (the

following year) is positive, while the matched-year local SST-chick count association is negative (that is,

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in matched-years, higher local SST is associated with lower chick counts), it could be that in the year

previous to the breeding year, the birds are foraging away from the coast, in the area that has cooler SST

when the coastal SST (in this case, the measured Seldovia SST) is warmer. For the Gulf of Alaska,

coastal temperature anomalies are often opposite central North Pacific anomalies (Appendices 12 and

13).

A possible explanation for unexpected significant advanced-year SST results is that a moving water mass

in one location (further south in the Pacific, for example, if birds were feeding there) affected the pre-

breeding condition of the birds for the matched years, but did not show up (move north) to be measured

in the Seldovia SST or the PDO until a year later. (However, for these variables there is significant

advance-year correlation for only the 20-mm Date parameter and not the others.)

It is interesting that for the two-year-lagged results, burrow count had the highest number of significant

results. Perhaps burrow count increases only after a successful breeding season. That is, if the pre-

breeding conditions (petrel parameters lagged one year) result in successful breeding, perhaps at the end

of that breeding season (after our burrow counts for that year had already been made), birds improved

burrows and prospected for more burrows. Then perhaps we would count more burrows the following

year (the second lagged year)?

Results from randomized-year correlations:

When the years for the petrel data were randomized and then compared with local SST (Appendix 11),

there were 2-4 significant correlations for each table, which is what we’d expect by chance for the 84

correlations. There were fewer consecutive-month (vertical in the tables) and linked-parameter (horizontal

in the tables) correlations than in any of the non-randomized tables. This experiment was repeated for

several randomized orders, with similar results each time.

The randomized year-order correlation lists show fewer associations among related parameters and

successive months than the correct-order lists show. By comparison it appears that the correct-order

current-, lagged-, and advanced-year lists do show many non-spurious relationships between the

environmental variables and the seabird parameters.

But relationships between petrel breeding parameters and environmental variables used in this report are

not likely to be simple. Probably the environmental variables have an indirect influence on the seabird

parameters. Apparently it’s not just that (for example) higher chick counts are always associated with

cool (or warm) SST because that SST indicates upwelling and mixed water (or stratified water), which

produces more prey for the parents. Probably (as we’d guess) the paths for both the environmental

drivers and the food web are more complicated. In addition, only a few environmental variables have

been tested here--there may be others that are more important. It’s possible that the environmental

variables tested here are only associated with more-important, more-direct variables.

The results in this report (including lag effects) will be explored further for their relationship with

environmental and food web variables. Statistical procedures and results will be refined.

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ACKNOWLEDGMENTS

Thanks to the many Biological Science Technicians and volunteers who helped with East Amatuli Island

fork-tailed storm-petrel monitoring through the years (listed in Appendix 14). Thanks to Don Dragoo and

Heather Renner for their helpful reviews of the report.

REFERENCES

Bailey, E. P. 1976. Breeding bird distribution and abundance in the Barren Islands, Alaska. The Murrelet

57(1):2-12.

Boersma, P. D. and J. K. Parrish 1998. Flexible growth rates in fork-tailed storm-petrels: A response to

environmental variability. The Auk 115(1):67-75.

Boersma, P. D. and J. K. Parrish 1996. Annual variation in seabird attendance and productivity on East

Amatuli Island, Barren Islands, Alaska: natural and human-induced effects. Minerals Management

Service report, MMS 96-0005, Anchorage, Alaska.

Boersma, P.D. 1986. Body temperature, torpor, and growth in chicks of fork-tailed storm-petrels

(Oceanodroma furcata). Physiological Zoology 59(1):10-19.

Boersma, P. D. 1982. Why some birds take so long to hatch. The American Naturalist 120(6):733-750.

Boersma, P.D., N. T. Wheelwright, M. K. Nerini, and E. S. Wheelwright 1980. The breeding biology of the

fork-tailed storm-petrel (Oceanodroma furcata). The Auk 97(2):268-282.

Boersma, P. D. and N. T. Wheelwright 1979(a). Egg Neglect in the Procellariiformes: Reproductive

Adaptations in the Fork-Tailed Storm-Petrel. The Condor 81(2):157-165.

Boersma, P. D. and N. T. Wheelwright 1979(b). Egg Chilling and the Thermal Environment of the Fork-

Tailed Storm Petrel (Oceanodroma furcata) Nest. Physiological Zoology 52(2):231-239.

Howie, M.G., I.T. Nimz and B.A. Drummond 2014. Biological monitoring at Aiktak Island, Alaska in 2013.

U.S. Fish and Wildlife Service Report, AMNWR 2014/01. Homer, Alaska.

Hurrell, J. & National Center for Atmospheric Research Staff (Eds). Last modified 27 May 2014. "The

Climate Data Guide: North Pacific (NP) Index by Trenberth and Hurrell; monthly and winter."

Retrieved from https://climatedataguide.ucar.edu/climate-data/north-pacific-np-index-trenberth-and-

hurrell-monthly-and-winter.

Kettle, A. B. 2013. Biological monitoring at East Amatuli Island, Alaska in 2011. U.S. Fish and Wildlife

Service Report, AMNWR 2013/03. Homer, Alaska.

Kettle, A. B. 2014. Biological monitoring at East Amatuli Island, Alaska in 2013. U.S. Fish and Wildlife

Service Report, AMNWR 2014/05. Homer, Alaska.

Manuwal, D. A. 1980. Breeding biology of seabirds on the Barren Islands, Alaska. U.S. Fish and Wildlife

Service report, Office of Biological Services, Anchorage, Alaska.

https://climatedataguide.ucar.edu/climate-data/north-pacific-np-index-trenberth-and-hurrell-monthly-and-winter

https://climatedataguide.ucar.edu/climate-data/north-pacific-np-index-trenberth-and-hurrell-monthly-and-winter

11

Nishimoto, M. 1990. Status of fork-tailed storm-petrels at East Amatuli Island during the summer of 1989.

U.S. Fish and Wildlife Service report, Alaska Maritime National Wildlife Refuge, Homer, Alaska.

Nishimoto, M. and K. O’Reilly 1989. Status of fork-tailed storm-petrels at East Amatuli Island during the

summer of 1988. U.S. Fish and Wildlife Service report, Alaska Maritime National Wildlife Refuge,

Homer, Alaska.

Nishimoto, M. and E. Beringer 1988. Status of fork-tailed storm-petrels at East Amatuli Island during the

summer of 1987. U.S. Fish and Wildlife Service report, Alaska Maritime National Wildlife Refuge,

Homer, Alaska.

Nishimoto, M., K Thounhurst, and S. Kirkhorn 1987. The status of fork-tailed storm-petrels and other

seabirds at East Amatuli Island during 1986. U.S. Fish and Wildlife Service report, Alaska Maritime

National Wildlife Refuge, Homer, Alaska.

Nishimoto, M. E. Bailey, and L. Climo 1986. Status of fork-tailed storm-petrels at East Amatuli Island

during the summer of 1985. U.S. Fish and Wildlife Service report, Alaska Maritime National Wildlife

Refuge, Homer, Alaska.

Roseneau, D. G., A. B. Kettle, and G. V. Byrd 2000. Common murre population monitoring at the Barren

Islands, Alaska, 1999. Exxon Valdez Oil Spill Restoration Project Final Report (Restoration Project

99144), U.S. Fish and Wildlife Service, Alaska Maritime National Wildlife Refuge, Homer, Alaska.

Simons. T. R. 1981. Behavior and attendance patterns of the fork-tailed storm-petrel. The Auk 98:145-

158.

Trenberth, K. E and J. W. Hurrell 1994. Decadal atmosphere-ocean variations in the Pacific. Climate

Dynamics (1994) 9:303-319.

Wilson, F. H., C. P. Hults, H. R. Schmoll, P. J. Haeussler, J. M. Schmidt, L. A. Yehle, and K. A. Labay

(compilers). 2009. Preliminary Geologic map of the Cook Inlet region, Alaska, including parts of the

Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia,

Mount Katmai, and Afognak 1:250,000-scale quadrangles. Open-File Report 2009-1108. U.S.

Department of the Interior, U.S. Geological Survey.

Zador, S., G.L. Hunt Jr, T. TenBrink, and K. Aydin 2013. Combined seabird indices show lagged

relationships between environmental conditions and breeding activity. Marine Ecology Progress

Series 485:245-258

12

FIGURES AND TABLES

13

Figure 1. Location of East Amatuli Island and other annual monitoring sites across the Alaska Maritime

National Wildlife Refuge.

Island maps

ISLAND MAPS

14

Figure 2. Location of the Barren Islands, Alaska

15

Figure 3. Map of the Barren Islands group.

16

Figure 4. East Amatuli Island, showing locations of common murre (COMU), black-legged kittiwake

(BLKI), tufted puffin (TUPU), and fork-tailed storm-petrel (FTSP) monitoring areas.

17

Figure 5. Line charts of wing chord measurements of fork-tailed storm-petrel chicks at East Amatuli

Island, Alaska in differing years 2002 (top) and 2011 (bottom), illustrating the potential for using this

information to calculate an annual index for timing of breeding.

Nesting date

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

10-J

un

13-J

un

16-J

un

19-J

un

22-J

un

25-J

un

28-J

un

1-J

ul

4-J

ul

7-J

ul

10-J

ul

13-J

ul

16-J

ul

19-J

ul

22-J

ul

25-J

ul

28-J

ul

31-J

ul

3-A

ug

6-A

ug

9-A

ug

12-A

ug

15-A

ug

18-A

ug

21-A

ug

24-A

ug

27-A

ug

30-A

ug

2-S

ep

5-S

ep

8-S

ep

11-S

ep

14-S

ep

17-S

ep

20-S

ep

23-S

ep

26-S

ep

29-S

ep

Win

g c

hord

(m

m)

Date

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

10-J

un

13-J

un

16-J

un

19-J

un

22-J

un

25-J

un

28-J

un

1-J

ul

4-J

ul

7-J

ul

10-J

ul

13-J

ul

16-J

ul

19-J

ul

22-J

ul

25-J

ul

28-J

ul

31-J

ul

3-A

ug

6-A

ug

9-A

ug

12-A

ug

15-A

ug

18-A

ug

21-A

ug

24-A

ug

27-A

ug

30-A

ug

2-S

ep

5-S

ep

8-S

ep

11-S

ep

14-S

ep

17-S

ep

20-S

ep

23-S

ep

26-S

ep

29-S

ep

Win

g c

hord

(m

m)

Date

2002

2011

18

Figure 6. Index of nesting date for fork-tailed storm-petrels at East Amatuli Island, Alaska. Yearly

deviation from the among-year mean (11 August) of the within-year mean date on which each chick was

calculated to have had a wing chord of 20 mm. This date was back-calculated for each chick using its

wing growth rate and the first measurement made between Julian dates 230 and 240. Positive values

indicate later-than-mean indices. Error bars show one standard deviation around each year’s mean “20-

mm Date”.

-30

-25

-20

-15

-10

-5

0

5

10

15

20

Anom

aly

(d)

Year

no

data

no

data

19

Table 1. Frequency distribution of 20mm Dates for fork-tailed storm-petrels at East Amatuli Island, Alaska.

Date Number of 20mm Dates

1997 1998 1999 2000 2001 2002 2003 2004 2005

11-Jul - - - no data - - - - -

12-Jul - - - - - - - - -

13-Jul - - - - - 1 - - -

14-Jul - - - - - - - - -

15-Jul - - - - - 1 - - -

16-Jul - - - - - 1 1 - -

17-Jul - - - - - 1 - - -

18-Jul - - - - - 2 - 2 -

19-Jul - - - - - - - - -

20-Jul - - - - - - - - -

21-Jul - - - - - 1 - 2 -

22-Jul - - - - - - - - -

23-Jul - - - - - - - - -

24-Jul - - - - - 1 - 2 -

25-Jul - - - - - - - 1 -

26-Jul - - - - - - - - -

27-Jul 1 - - - - - - - 1

28-Jul - - - - - - - - -

29-Jul 1 - - - - 1 - 3 -

30-Jul - - - - - - - - -

31-Jul - - - - - - - 1 -

1-Aug - - 1 - 1 1 - 1 1

2-Aug 1 - - - - 1 - - -

3-Aug - - - - 1 - - - 2

4-Aug 1 - - - 2 1 - 1 1

5-Aug 1 - - - - - - 1 1

6-Aug 1 - 3 - - - 1 - 1

7-Aug - - - - - - - - -

8-Aug - - - - - - - 1 -

9-Aug 1 - - - 1 - 1 - 2

10-Aug 1 - 1 - 3 - - - -

11-Aug 1 - 1 - - 1 - - -

12-Aug - - 1 - 2 - - - 1

13-Aug - - 2 - 1 1 1 - -

14-Aug - - 1 - 1 1 - - 2

15-Aug - - 3 - - 1 - - 2

16-Aug 1 1 1 - 2 - 1 - -

17-Aug 3 1 3 - 2 - 2 - 1

18-Aug 2 - 1 - - - - - 2

19-Aug - 2 - - 1 - - - 1

20-Aug - - - - - 1 - 1 -

21-Aug - 2 - - 1 - - 1 -

22-Aug - - - - - - 2 - -

23-Aug - 2 - - - - - - -

24-Aug - 1 - - - - 1 - 1

25-Aug - 1 - - - - - - -

26-Aug - 1 1 - - - - - -

27-Aug - - - - - - - - -

28-Aug - - - - - - - - -

29-Aug - - - - - - - - -

30-Aug - - - - - - - - -

31-Aug - - - - - - - - -

n 15 11 18 0 18 16 8 17 19

20

Table 1 (continued). Frequency distribution of 20mm Dates for fork-tailed storm-petrels at East Amatuli Island, Alaska.

Date Number of 20mm Dates

2006 2007 2008 2009 2010 2011 2012 2013

11-Jul - - - - - - no data -

12-Jul - - - 1 - - - -

13-Jul - - - - - - - -

14-Jul - - - - - - - -

15-Jul - - - - - - - 1

16-Jul - - - - - - - -

17-Jul - - - - - - - -

18-Jul - - - - - - - -

19-Jul - - - - - - - 1

20-Jul - - - - - - - -

21-Jul 1 - - - - - - -

22-Jul - - - - - - - -

23-Jul - - - - - - - -

24-Jul - - 1 - - - - 1

25-Jul - - - - - - - 1

26-Jul - - - - - - - 1

27-Jul 1 - - - - - - -

28-Jul 1 - - - - - - -

29-Jul - - - 1 - - - 1

30-Jul 2 - - - - - - -

31-Jul 1 - - - - - - -

1-Aug - - - - - - - -

2-Aug 2 1 1 - - - - -

3-Aug 1 - 1 1 1 - - -

4-Aug - 3 - - - - - 2

5-Aug 3 - 1 2 - - - 1

6-Aug 2 1 - 1 - 1 - -

7-Aug 1 3 - 2 - 1 - 1

8-Aug 1 1 1 1 - - - 2

9-Aug 1 - - 3 - - - 3

10-Aug - 1 - - - 1 - 1

11-Aug - - 2 - 1 - - -

12-Aug - 2 1 1 - 1 - 1

13-Aug 1 - - 1 1 - - -

14-Aug 1 4 - 1 - - - 1

15-Aug - - 2 3 1 1 - -

16-Aug 2 2 3 1 2 - - 2

17-Aug - 1 3 1 1 1 - 2

18-Aug 1 1 2 1 - 1 - 1

19-Aug 2 - 1 - 3 1 - -

20-Aug - 4 1 - 2 3 - 1

21-Aug - 1 1 1 - - - 1

22-Aug - 3 - - - - - -

23-Aug - - 1 1 - 2 - 1

24-Aug - - - - - - - -

25-Aug - - 2 - - - - -

26-Aug - - - - - - - -

27-Aug - - - 1 - - - -

28-Aug - - 1 - - - - -

29-Aug - - - - - - - 1

30-Aug - - - - - - - -

31-Aug - - - - - - - -

n 24 28 24 23 12 13 0 27

21

Table 2. “20-mm Date” index of nesting date for fork-tailed storm-petrels at East Amatuli Island, Alaska. Yearly anomaly from the among-year

mean of the within-year mean date when chicks were calculated to have had a wing chord of 20 mm. This date was back-calculated for each chick

using its wing growth rate and the first measurement made between Julian dates 230 and 240. Positive values indicate later-than-mean indices.

Only chicks with a growth rate with linear correlation coefficient of determination (R-squared) of ≥ 0.80 were included.

Parameter 1997 1998 1999 2000 2001 2002 2003 2004 2005

n 15 11 19 no data 18 17 10 17 19

Back-calculated 20mm Date (Julian) 221.67 233.31 224.93 - 223.64 211.32 229.6 211.42 222.64

Date of above 10 Aug 21 Aug 13 Aug - 12 Aug 30 Jul 18 Aug 30 Jul 10 Aug

SD 7.51 3.16 5.72 - 5.86 12.52 5.04 10.10 7.33

Anomaly from among-year mean (11

August) -1.78 9.87 1.49 - 0.19 -12.12 6.15 -11.92 0.70

Table 2 (continued).

Parameter 2006 2007 2008 2009 2010 2011 2012 2013

n 24 28 24 23 12 13 no data 27

Back-calculated 20mm Date (Julian) 218.4 225.24 227.73 223.79 227.64 228.18 - 220.49

Date of above 6 Aug 13 Aug 16 Aug 12 Aug 16 Aug 16 Aug - 8 Aug

SD 7.9 6.43 6.68 6.79 4.81 5.69 - 10.84

Anomaly from among-year mean (11

August) -5.05 1.79 4.29 0.34 4.2 4.73 - -2.95

22

Figure 7. Number of fork-tailed storm-petrel chicks found in population plots at East Amatuli Island,

Alaska. Expressed as the proportion of the among-year maximum count in Plots 1-4 and 6-11 in 2001

and Plots 1-11 in all other years.

Figure 8. Number of large (mass >= 50 g) fork-tailed storm-petrel chicks found in population plots at East

Amatuli Island, Alaska. Expressed as the proportion of the among-year maximum count in Plots 1-4 and

6-11 in 2001 and Plots 1-11 in all other years.

Reproductive performance

0.00

0.20

0.40

0.60

0.80

1.00

1.20P

ropotion o

f m

axim

um

Year

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Pro

potion o

f m

axim

um

Year

23

Figure 9. Proportion of burrows that contained chicks at East Amatuli Island, Alaska.

Figure 10. Proportion of burrows that contained “Large” (mass >= 50 g) chicks at East Amatuli Island,

Alaska.

0.00

0.05

0.10

0.15

0.20

0.25

0.30C

hic

ks / n

ests

Year

0.00

0.05

0.10

0.15

0.20

0.25

Chic

ks / n

ests

Year

24

Figure 11. Proportion of fork-tailed storm-petrel chicks that reached “Large” size (mass >= 50 g) in

productivity plots at East Amatuli Island, Alaska.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Larg

e c

hic

ks / c

hic

ks

25

Table 3. Indices for reproductive success (proportion of burrows that contain chicks and proportion of chicks that survive to “Large” size) at East

Amatuli Island, Alaska. Index for “fledging success” (bottom row) from Table 7.

Parameter 1998 1999 2000 2001a 2002 2003 2004 2005

Burrows 488 573 531 558 613 584 633 469

Burrows with a chick 26 108 40 82 94 96 124 107

Burrows that produced a “large” (mass > 50 g) chick 16 88 22 37 83 66 107 84

Proportion of burrows with a chick 0.053 0.188 0.075 0.147 0.153 0.164 0.196 0.228

Proportion of burrows with a “large” chick 0.033 0.154 0.041 0.066 0.135 0.113 0.169 0.179

Proportion of chicks that survived to “large” sizeb 0.474 0.804 0.350 0.378 0.927 0.723 0.944 0.920

a One plot was inadvertently omitted from field work in 2001; data are for 10 plots rather than all eleven.

b Each year there was a small proportion of chicks that either could not be measured or were alive but had not yet reached 50 g when we departed from the

island. Table 7 calculates fledging success by omitting those nests. It is that calculation given here.

Table 3 (continued). Indices for reproductive success (proportion of burrows that contain chicks and proportion of chicks that survive to “Large”

size) at East Amatuli Island, Alaska. Index for “fledging success” (bottom row) from Table 7.

Parameter 2006 2007 2008 2009 2010 2011 2012 2013

Burrows 453 572 582 640 705 668 no data 618

Burrows with a chick 128 138 81 89 87 83 - 73

Burrows that produced a “large” (mass > 50 g) chick 105 102 49 77 63 69 - 60

Proportion of burrows with a chick 0.260 0.241 0.139 0.139 0.123 0.124 - 0.118

Proportion of burrows with a “large” chick 0.213 0.178 0.084 0.120 0.089 0.103 - 0.097

Proportion of chicks that survived to “large” sizeb 0.879 0.894 0.533 0.947 0.953 0.941 - 0.950

a One plot was inadvertently omitted from field work in 2001; data are for 10 plots rather than all eleven.

b Each year there was a small proportion of chicks that either could not be measured or were alive but had not yet reached 50 g when we departed from the

island. Table 7 calculates fledging success by omitting those nests. It is that calculation given here.

26

Table 4. Number of chicks found in fork-tailed storm-petrel plots at East Amatuli Island, Alaska.

Year

Plota

Sum of

11 plots

Prop.

of

max.d

Sum

w/o

Plot 5

Prop.

of

max.e

Prop. of

max of all

plots

surveyedf

1 2 3 4 5 6 7 8 9 10 11

1998 1 0 1 0 3 7 2 2 1 7 2 26 0.19 23 0.18 0.19

1999 11 4 13 4 12 18 12 9 11 9 5 108 0.78 96 0.73 0.78

2000 7 2 9 1 1 8 1 2 2 6 1 40 0.29 39 0.30 0.29

2001 11 5 13 4 no

datab

9 8 14 8 7 3 - - 82 0.63 0.63

2002 7 7 16 2 4 13 10 11 9 12 3 94 0.68 90 0.69 0.68

2003 4 6 14 3 6 11 17 16 6 8 5 96 0.70 90 0.69 0.70

2004 11 9 17 4 8 19 17 18 11 6 4 124 0.90 116 0.89 0.90

2005 17 8 14 6 5 15 6 16 7 10 3 107 0.78 102 0.78 0.78

2006 16 13 17 2 11 19 11 14 14 8 3 128 0.93 117 0.89 0.93

2007 10 14 24 2 7 18 13 20 15 11 4 138 1.00 131 1.00 1.00

2008 7 8 16 2 4 8 10 10 4 9 3 81 0.59 77 0.59 0.59

2009 6 11 10 1 5 2 13 20 10 7 4 89 0.64 84 0.64 0.64

2010 6 5 6 4 3 13 14 17 7 8 4 87 0.63 84 0.64 0.63

2011 6 5 7 2 3 11 16 15 6 8 4 83 0.60 80 0.61 0.60

2012 no

data - - - - - - - - - - - - - - -

2013 9 3 4 2 7 7 11 9 6 10 5 73 0.53 66 0.56 0.53

Max.c 138 131

a For this table plots have for this table been numbered east-to-west:1=plot “AW”; 2=“AE”; 3=“B”; 4=“EWL”; 5=“EWU”; 6=“EEL”; 7=“EEU”; 8=“DL”; 9=“DM”;

10=“DU”; 11=“F”. b

In 2001 plot 5 was accidentally omitted from the field surveys. c Among-years maximum of sum of Plots 1-11

d (Sum from Plots 1-11) / (among-year maximum).

e (Sum from plots 1-4 and 6-11) / (among-year maximum).

f Proportion of among-year maximum for either plots 1-4 and 6-11 (2001) or plots 1-11 (all other years).

27

Table 5. Number of large (>=50 g by end of field season) chicks found in fork-tailed storm-petrel plots at East Amatuli Island, Alaska.

Year

Plota

Sum of

11 plots

Prop.

of

max.d

Sum

w/o

Plot 5

Prop.

of

max.e

Prop. of

max. of all

plots

surveyedf

1 2 3 4 5 6 7 8 9 10 11

1998 0 0 1 0 2 3 1 2 0 5 2 16 0.15 14 0.14 0.15

1999 8 3 13 2 8 17 8 6 9 9 5 88 0.82 80 0.79 0.82

2000 4 1 4 1 1 4 0 1 2 3 1 22 0.21 21 0.21 0.21

2001 7 4 7 2 no

datab

4 3 5 2 2 1 - - 37 0.37 0.37

2002 5 7 14 1 4 12 9 10 9 9 3 83 0.78 79 0.78 0.78

2003 3 4 7 2 4 8 8 12 6 7 5 66 0.62 62 0.61 0.62

2004 10 8 16 3 6 15 16 16 9 4 4 107 1.00 101 1.00 1.00

2005 16 7 12 3 4 12 5 11 6 6 2 84 0.79 80 0.79 0.79

2006 8 9 14 1 10 18 11 14 12 5 3 105 0.98 95 0.94 0.98

2007 6 10 17 2 5 15 8 16 12 8 3 102 0.95 97 0.96 0.95

2008 5 6 8 1 2 4 7 5 3 6 2 49 0.46 47 0.47 0.46

2009 6 9 9 1 4 2 13 16 8 7 2 77 0.72 73 0.72 0.72

2010 5 4 3 3 2 10 12 10 5 6 3 63 0.59 61 0.60 0.59

2011 5 4 6 2 2 10 13 13 5 5 4 69 0.64 67 0.66 0.64

2012 no

data - - - - - - - - - - - - - - -

2013 7 3 4 2 6 6 9 8 3 8 4 60 0.56 54 0.59 0.56

Max.c 107 101

a Plots have for this table been numbered east-to-west:1=Plot “AW”; 2=“AE”; 3=“B”; 4=“EWL”; 5=“EWU”; 6=“EEL”; 7=“EEU”; 8=“DL”; 9=“DM”; 10=“DU”; 11=“F”.

b In 2001 plot 5 was accidentally omitted from the field surveys.

c Among-years maximum of sum of Plots 1-11




28

Table 6. By-plot reproductive performance of fork-tailed storm-petrels at East Amatuli Island, Alaska.

2013 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 50 60 35 28 69 86 101 81 28 61 19 618

Chicks (b) 9 3 4 2 7 7 11 9 6 10 5 73

Chicks weighed (c) 7 3 4 2 6 6 10 8 4 8 5 63

Chicks that reached 50 g (d) 7 3 4 2 6 6 9 8 3 8 4 60

Chicks alive but <50 g when we departed (e) 0 0 1 0 0 0 0 0 0 0 2 3

Chicks/Burrows (b/a) 0.18 0.05 0.11 0.07 0.10 0.08 0.11 0.11 0.21 0.16 0.26 0.12

Chicks that reached 50 g /Burrows (d/a) 0.14 0.05 0.11 0.07 0.09 0.07 0.09 0.10 0.11 0.13 0.21 0.10

2011 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 57 50 37 29 74 87 113 91 35 79 16 668

Chicks (b) 6 5 7 2 3 11 16 15 6 8 4 83

Chicks weighed (c) 6 4 7 2 2 11 13 13 5 6 4 73





29

Table 6 (continued). By-plot reproductive performance of fork-tailed storm-petrels at East Amatuli Island, Alaska.

2010 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 58 64 44 41 70 93 123 92 37 71 12 705

Chicks (b) 6 5 6 4 3 13 14 17 7 8 4 87

Chicks weighed (c) 5 4 4 3 2 12 12 10 5 6 3 66





2009 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 53 53 35 38 56 74 108 107 36 64 16 640

Chicks (b) 6 11 10 1 5 2 13 20 10 7 4 89

Chicks weighed (c) 6 9 9 1 4 2 13 17 9 7 4 81





30


2008 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 45 40 45 37 55 77 87 93 30 61 12 582

Chicks (b) 7 8 16 2 4 8 10 10 4 9 3 81

Chicks weighed (c) 6 6 13 1 4 7 10 7 4 9 3 70





2007 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 47 55 48 23 57 69 85 86 31 58 13 572

Chicks (b) 10 14 24 2 7 18 13 20 15 11 4 138

Chicks weighed (c) 8 11 19 2 7 17 9 16 13 8 3 113





31


2006 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 49 43 37 22 49 66 90 55 32 38 12 493

Chicks (b) 16 13 17 2 11 19 11 14 14 8 3 128

Chicks weighed (c) 15 12 16 1 10 18 11 14 13 5 3 118





2005 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 48 45 37 19 53 63 76 52 26 44 6 469

Chicks (b) 17 8 14 6 5 15 6 16 7 10 3 107

Chicks weighed (c) 17 7 14 4 4 13 5 12 7 6 2 91





32


2004 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 63 57 43 35 69 73 93 88 32 67 13 633

Chicks (b) 11 9 17 4 8 19 17 18 11 6 4 124

Chicks weighed (c) 11 9 17 3 7 15 16 17 9 5 4 113





2003 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 51 44 35 20 64 77 72 86 38 81 16 584

Chicks (b) 4 6 14 3 6 11 17 16 6 8 5 96

Chicks weighed (c) 4 4 12 3 4 9 15 15 6 7 5 84





33


2002 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 52 49 44 24 55 80 105 80 38 71 15 613

Chicks (b) 7 7 16 2 4 13 10 11 9 12 3 94

Chicks weighed (c) 6 7 17 1 4 13 9 11 9 9 3 89





2001 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 53 51 52 25 no

data 80 98 86 36 64 13 558

Chicks (b) 11 5 13 4 - 9 8 14 8 7 3 82

Chicks weighed (c) 8 4 10 4 - 8 6 10 4 4 2 60

Chicks that reached 50 g (d) 7 4 7 2 - 4 3 5 2 2 1 37

Chicks alive but <50 g when we departed (e) 1 0 3 2 - 4 3 5 2 2 1 23

Chicks/Burrows (b/a) 0.21 0.10 0.25 0.16 - 0.11 0.08 0.16 0.22 0.11 0.23 0.15

Chicks that reached 50 g /Burrows (d/a) 0.13 0.08 0.13 0.08 - 0.05 0.03 0.06 0.06 0.03 0.08 0.07

34


2000 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 44 43 51 24 54 79 82 58 27 54 15 531

Chicks (b) 7 2 9 1 1 8 1 2 2 6 1 40

Chicks weighed (c) 7 1 7 1 1 8 0 2 2 5 1 35





1999 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 53 49 48 25 64 79 92 69 25 55 14 573

Chicks (b) 11 4 13 4 12 18 12 9 11 9 5 108

Chicks weighed (c) 10 4 15 3 10 19 12 9 10 9 5 106





35


1998 Plot

Total

1 2 3 4 5 6 7 8 9 10 11

Burrows (a) 50 45 47 16 58 72 79 18 61 24 18 488

Chicks (b) 1 0 1 0 3 7 2 2 1 7 2 26

Chicks weighed (c) 1 0 3 0 4 6 2 2 0 6 2 26





36

Table 7. Grouped-plot reproductive performance of fork-tailed storm-petrels at East Amatuli Island, Alaska. Plots were grouped to increase chick

sample size for calculation of mean and standard deviation among plots.

2013 Plot

Totala SD

b

1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 9 7 9 7 11 14 6 10 73 -

Chicks weighed (c) 7 7 8 6 10 13 4 8 63 -

Chicks that reached 50 g (d) 7 7 8 6 9 12 3 8 60 -

Chicks alive but <50 g when we departed (e) 0 1 0 0 0 2 0 0 3 -

Large chicks/chicks ((d-e)/(c-e)) 1.00 1.00 1.00 1.00 0.90 0.91 0.75 1.00 0.95 0.02

a The sample unit for the fledging success index point calculation is the nest-site (not plots).

b Standard deviation was calculated with ratio estimation, using plots as the sample unit.

2011 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 6 12 5 11 16 19 6 8 83 -

Chicks weighed (c) 6 11 4 11 13 17 5 6 73 -




2010 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 6 11 7 13 14 21 7 8 87 -

Chicks weighed (c) 5 8 5 12 12 13 5 6 66 -




37

Table 7 (continued). Grouped-plot reproductive performance of fork-tailed storm-petrels at East Amatuli Island, Alaska. Plots were grouped to

increase chick sample size for calculation of mean and standard deviation among plots.

2009 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 6 21 6 2 13 24 10 7 89 -

Chicks weighed (c) 6 18 5 2 13 21 9 7 81 -




2008 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 7 24 6 8 10 13 4 9 81 -

Chicks weighed (c) 6 19 5 7 10 10 4 9 70 -




2007 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 10 38 9 18 13 24 15 11 138 -

Chicks weighed (c) 8 30 9 17 9 19 13 8 113 -




38


increase chick sample size for calculation of mean and standard deviation among plots.

2006 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 16 30 13 19 11 17 14 8 128 -

Chicks weighed (c) 15 28 11 18 11 17 13 5 118 -




2005 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 19 23 11 15 6 19 7 10 110 -

Chicks weighed (c) 19 22 8 13 5 14 7 6 94 -




2004 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 11 26 12 19 17 22 11 6 124 -

Chicks weighed (c) 11 26 10 15 16 21 9 5 113 -




39


increase chick sample size for calculation of mean and standard deviation among plots. “nd” indicates sample insufficient for fledging success

calculation.

2003 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 4 20 9 11 17 21 6 8 96 -

Chicks weighed (c) 4 16 7 9 15 20 6 7 84 -




2002 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 7 23 6 13 10 14 9 12 94 -

Chicks weighed (c) 6 24 5 13 9 14 9 9 89 -




2001 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 11 18 no data 9 8 17 8 7 82 -

Chicks weighed (c) 8 14 - 8 6 12 4 4 60 -

Chicks that reached 50 g (d) 7 11 - 4 3 6 2 2 37 -

Chicks alive but <50 g when we departed (e) 1 3 - 4 3 6 2 2 23 -

Large chicks/chicks ((d-e)/(c-e)) 0.86 0.73 - nd nd nd nd nd 0.38 nd

40


increase chick sample size for calculation of mean and standard deviation among plots. “nd” indicates sample insufficient for fledging success

calculation.

2000 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 7 11 2 8 1 3 2 7 40 -

Chicks weighed (c) 7 8 2 8 0 3 2 6 35 -



Large chicks/chicks ((d-e)/(c-e)) nd nd nd nd nd nd nd nd 0.35 nd

1999 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 11 17 16 18 12 14 11 9 108 -

Chicks weighed (c) 10 19 13 19 12 14 10 9 106 -




1998 Plot

Total SD 1 2+3 4+5 6 7 8+11 9 10

Chicks (b) 1 1 3 7 2 4 1 7 26 -

Chicks weighed (c) 1 3 4 6 2 4 0 6 26 -



Large chicks/chicks ((d-e)/(c-e)) nd nd nd nd nd nd nd nd 0.47 nd

41

Figure 12. Mean mass gain of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. The minimum

R-squared values for slope inclusion was = 0.8.

Figure 13. Mean mass gain of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. No minimum

R-squared-value limit.

Chick growth

0.00

0.50

1.00

1.50

2.00

2.50

3.00G

ram

s p

er

day

Years

0.00

0.50

1.00

1.50

2.00

2.50

3.00

Gra

ms p

er

day

Years

no

data

no

data

42

Figure 14. Mean wing growth rate of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. The

minimum R-squared value for slope inclusion was = 0.8.

Figure 15. Mean wing growth of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska (except no

measurements in 2012). No minimum R-squared-value limit.

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

Mili

mete

rs p

er

day

Years

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

Mili

mete

rs p

er

day

Years

no

data

no

data

no

data

no

data

43

Figure 16. Scatterplot of mean annual mass growth rate and wing growth rate for fork-tailed storm-petrel

chicks at East Amatuli Island, Alaska during 1997-2013 (except no measurements in 2012). The minimum

R-squared value for inclusion of individual chicks’ growth slope was = 0.8.

1.50

1.70

1.90

2.10

2.30

2.50

2.70

2.90

3.10

3.30

3.50

0.00 0.50 1.00 1.50 2.00 2.50

Win

g g

row

th r

ate

(m

m/d

)

Mass growth rate (g/d)

44

Table 8. Mean growth rates of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. Minimum R-squared filter = 0.8.

Year Mass Wing chord

Mean SD n Mean SD n

1997 1.35 0.38 5 2.13 0.50 15

1998 2.18 0.45 7 2.08 0.62 11

1999 1.43 0.45 6 2.63 0.67 18

2000 no data - - no data - -

2001 0.96 0.33 9

1.87 0.61 21

2002 1.74 0.22 7

2.72 0.49 16

2003 1.61 0.52 29

2.38 0.62 23

2004 0.93 1.41 7

3.02 0.68 17

2005 1.25 0.61 12

2.69 0.50 19

2006 1.13 0.32 6

2.80 0.40 24

2007 1.24 0.41 15

2.84 0.57 29

2008 1.19 0.27 16

1.83 0.80 32

2009 1.87 0.50 15

2.94 0.52 23

2010 1.97 0.83 14

3.22 0.52 27

2011 0.84 0.61 25

2.41 0.65 34

2012

2013 0.62 0.99 10 2.94 0.59 27

45

Figure 17. Number of fork-tailed storm-petrel burrows counted in population plots at East Amatuli Island,

Alaska. Expressed as proportion of the among-year maximum count in Plots 1-4 and 6-11 (2001) and

Plots 1-11 (all other years).

Population trend

0.000

0.200

0.400

0.600

0.800

1.000

1.200

Pro

port

ion o

f m

axim

um

Year

46

Table 9. Number of burrows in fork-tailed storm-petrel plots at East Amatuli Island, Alaska.

Year

Plota

Sum of

11 plots

Prop.

of

max.d

Sum

w/o

Plot 5

Prop.

of

max.e

Prop.

of max.

combinedf

1 2 3 4 5 6 7 8 9 10 11

1998 50 45 47 16 58 72 79 18 61 24 18 488 0.69 430 0.68 0.69

1999 53 49 48 25 64 79 92 69 25 55 14 573 0.81 509 0.80 0.81

2000 44 43 51 24 54 79 82 58 27 54 15 531 0.75 477 0.75 0.75

2001 53 51 52 25 no

datab

80 98 86 36 64 13 - - 558 0.88 0.88

2002 52 49 44 24 55 80 105 80 38 71 15 613 0.87 558 0.88 0.87

2003 51 44 35 20 64 77 72 86 38 81 16 584 0.83 520 0.82 0.83

2004 63 57 43 35 69 73 93 88 32 67 13 633 0.90 564 0.89 0.90

2005 48 45 37 19 53 63 76 52 26 44 6 469 0.67 416 0.66 0.67

2006 49 43 37 22 49 66 90 55 32 38 12 493 0.70 444 0.70 0.70

2007 47 55 48 23 57 69 85 86 31 58 13 572 0.81 515 0.81 0.81

2008 45 40 45 37 55 77 87 93 30 61 12 582 0.83 527 0.83 0.83

2009 53 53 35 38 56 74 108 107 36 64 16 640 0.91 584 0.92 0.91

2010 58 64 44 41 70 93 123 92 37 71 12 705 1.00 635 1.00 1.00

2011 57 50 37 29 74 87 113 91 35 79 16 668 0.95 594 0.94 0.95

2012 no data - - - - - - - - - - - - - -

2013 50 60 35 28 69 86 101 81 28 61 19 617 0.88 548 0.86 0.88

Max.c 705 635

a Plots have for this table been numbered east-to-west:1=Plot “AW”; 2=“AE”; 3=“B”; 4=“EWL”; 5=“EWU”; 6=“EEL”; 7=“EEU”; 8=“DL”; 9=“DM”; 10=“DU”; 11=“F”.

b In 2001 plot 5 was accidentally omitted from the field surveys.

c Among-years maximum of sum of Plots 1-11




47

Table 10. Frequency of occurrence of prey types (percentage of samples containing each prey type) in

regurgitation samples from mistnetted fork-tailed storm-petrels at East Amatuli Island, Alaska.

Prey 2011 2012 2013

No. samples 15 No samples collected 22

Invertebrates 80.0 - not yet analyzed

Amphipoda 40.0 - -

Gammaridea 40.0 - -

Unid. lysianassid 40.0 - -

Euphausiaceae 53.3 - -

Thysanoessa intermis 20.0 - -

Thysanoessa spinifera 6.7 - -

Unid. thysanoessid 20.0 - -

Unid. euphausiid 6.7 - -

Decapoda 6.7 - -

Unid. shrimp 6.7 - -

Fish 60.0 - -

Myctophidae 40.0 - -

Unid. myctophid 40.0 - -

Osmeridae 6.7 - -

Mallotus villosus 6.7 - -

Unid. fish 13.3 - -

Unid. non-larval fish 6.7 - -

Unid. larval fish 6.7 - -

Other 6.7 - -

Unid. offal 6.7 - -

Chick diet

48

Table 11. Prey composition (for each prey type, percentage of the total number of items of all prey types)

in regurgitation samples from mistnetted fork-tailed storm-petrels at East Amatuli Island, Alaska.

Prey 2011 2012 2013

No. samples 15 No samples collected 22

Invertebrates 80.4 - not yet analyzed

Amphipoda 14.5 - -

Gammaridea 14.5 - -

Unid. lysianassid 14.5 - -

Euphausiaceae 65.2 - -

Thysanoessa intermis 7.2 - -

Thysanoessa spinifera 4.4 - -

Unid. thysanoessid 42.8 - -

Unid. euphausiid 10.9 - -

Decapoda 0.7 - -

Unid. shrimp 0.7 - -

Fish 14.5 - -

Myctophidae 4.4 - -

Unid. myctophid 4.4 - -

Osmeridae 5.8 - -

Mallotus villosus 5.8 - -

Unid. fish 13.3 - -

Unid. non-larval fish 6.5 - -

Unid. larval fish 2.2 - -

Other 0.7 - -

Unid. offal 0.7 - -

49

APPENDICES

APPENDICES

50

Wing Mass

Appendix 1. Line charts of chick growth data at East Amatuli Island, Alaska. Wing chord is shown on the

left; mass growth on the right. Each line shows one chick’s growth. This illustrates the degree of linearity

of wing growth, the lack of linearity in the mass growth, and the degree of among-chick synchrony in

each.

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51

Wing Mass

Appendix 1 (continued). Line charts of chick growth data at East Amatuli Island, Alaska. Wing chord is

shown on the left; mass growth on the right. Each line shows one chick’s growth. This illustrates the

degree of linearity of wing growth, the lack of linearity in the mass growth, and the degree of among-chick

synchrony in each.

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52

Wing Mass



degree of linearity of wing growth, the lack of linearity in the mass growth, and the degree of among-chick

synchrony in each.

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53

Wing Mass



degree of linearity of wing growth, the lack of linearity in the mass growth, and the degree of asynchrony

in both. Vertical lines on the 2013 wing chart indicate Julian Dates 230 and 240; wing lengths for back-

calculation of “20-mm Dates” were sampled from this date range for all years.

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54

Appendix 2. Tukey post-hoc test p-values ≤0.05 for timing-of-nesting index (“20-mm Date”) for fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. Greater-than symbols (>)

indicate p-values >0.05. Sign in parentheses shows direction of the column-year value’s difference from the row-year value: plus-signs indicate significantly later 20-mm Dates in the

column-year; minus-signs indicate significantly earlier 20-mm Dates in the column-year.

Year 1998 1999 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2013

1997 0.015(+) > > 0.019(-) > 0.018(-) > > > > > > > >

1998 - > > <0.001(-) > <0.001(-) 0.025(-) <0.001(-) > > > > > 0.001(-)

1999 - - > <0.001(-) > <0.001(-) > > > > > > > >

2001 - - - 0.001(-) > <0.001(-) > > > > > > > >

2002 - - - - <0.001(+) > 0.002(+) > <0.001(+) <0.001(+) <0.001(+) <0.001(+) <0.001(+) 0.017(+)

2003 - - - - - <0.001(-) > 0.034(-) > > > > > >

2004 - - - - - - 0.002(+) > <0.001(+) <0.001(+) <0.001(+) <0.001(+) <0.001(+) 0.015(+)

2005 - - - - - - - > > > > > > >

2006 - - - - - - - - > 0.004(+) > > 0.023(+) >

2007 - - - - - - - - - > > > > >

2008 - - - - - - - - - - > > > >

2009 - - - - - - - - - - - > > >

2010 - - - - - - - - - - - - > >

2011 - - - - - - - - - - - - - >

55

Appendix 3. Deviation from the among-year mean for “20-mm Date” (estimated hatch date back-calculated from first wing measurement and

growth slope of each chick) at East Amatuli, Alaska and for hatch date at Aiktak Island, Alaska. “nd” = “No Data”. Aiktak data from Howie, et al.

2014.

-15

-10

-5

0

5

10

15

20

19

96

19

97

19

98

19

99

20

00

20

01

20

02

20

03

20

04

20

05

20

06

20

07

20

08

20

09

20

10

20

11

20

12

20

13

EastAmatuli

Aiktaknd nd nd nd

56

Appendix 4. Tukey post-hoc test p-values ≤0.05 for mass growth of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. The minimum R-squared value for mass gain slope

inclusion was 0.8. Greater-than symbols (>) indicate p-values >0.05. Sign in parentheses shows direction of the column-year value’s difference from the row-year value: plus-signs

indicate faster growth in the column-year; minus-signs indicate slower growth in the column-year.

Year 1998 1999 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2013

1997 > > > > > > > > > > > > > >

1998 - > 0.009(-) > > 0.014(-) > > > 0.034(-) > > <0.001(-) <0.001(-)

1999 - - > > > > > > > > > > > >

2001 - - - > > > > > > > 0.039(+) 0.013(+) > >

2002 - - - - > > > > > > > > 0.047(-) 0.020(-)

2003 - - - - - > > > > > > > 0.001(-) 0.002(-)

2004 - - - - - - > > > > > 0.023(+) > >

2005 - - - - - - - > > > > > > >

2006 - - - - - - - - > > > > > >

2007 - - - - - - - - - > > > > >

2008 - - - - - - - - - - > 0.045(+) > >

2009 - - - - - - - - - - - > <0.001(-) <0.001(-)

2010 - - - - - - - - - - - - <0.001(-) <0.001(-)

2011 - - - - - - - - - - - - - -

57

Appendix 5. Tukey post-hoc test p-values ≤0.05 for wing chord growth of fork-tailed storm-petrel chicks at East Amatuli Island, Alaska. The minimum R-squared value for growth slope

inclusion was 0.8. Greater-than symbols (>) indicate p-values >0.05. Sign in parentheses shows direction of the column-year value’s difference from the row-year value: plus-signs

indicate faster growth in the column-year; minus-signs indicate slower growth in the column-year.

Year 1998 1999 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2013

1997 > > > > > 0.003(+) > > 0.018(+) > 0.005(+) <0.001(+) > 0.003(+)

1998 - > > > > 0.005(+) > > 0.029(+) > 0.009(+) <0.001(+) > 0.006(+)

1999 - - 0.008(-) > > > > > > 0.001(-) > 0.085(+) > >

2001 - - - 0.002(+) > <0.001(+) 0.002(+) <0.001(+) <0.001(+) > <0.001(+) <0.001(+) > <0.001(+)

2002 - - - - > > > > > <0.001(-) > > > >

2003 - - - - - > > > > > > <0.001(+) > >

2004 - - - - - - > > > <0.001(-) > > 0.044(-) >

2005 - - - - - - - > > <0.001(-) > > > >

2006 - - - - - - - - > <0.001(-) > > > >

2007 - - - - - - - - - <0.001(-) > > > >

2008 - - - - - - - - - - <0.001(+) <0.001(+) 0.011(-) <0.001(+)

2009 - - - - - - - - - - - > > >

2010 - - - - - - - - - - - - <0.001(-) >

2011 - - - - - - - - - - - - - 0.041(+)

58

Appendix 6. Pearson correlation coefficients for annual parameter values of fork-tailed storm-petrel at East Amatuli Island, Alaska for the years

1998-2013. Greater-than symbols (>) indicate p-values >0.05; p-values ≤ 0.05 are in parentheses. In the analysis earlier 20-mm Dates were

numerically smaller than later dates.

Parameter 20-mm Date Chicks

Large Chicks

Fledging Success

Wing Growth

Mass Gain

r (p) r (p) r (p) r (p) r (p) r (p)

Chicks -0.519 > - - - - - - - - - -

Large Chicks -0.634 (0.015) 0.936 (<0.001) - - - - - - - -

Fledging Success -0.461 > 0.613 (0.015) 0.795 (<0.001) - - - - - -

Wing Growth -0.417 > 0.462 > 0.664 (0.010) 0.896 (<0.001) - - - -

Mass Gain 0.338 > -0.374 > -0.288 > -0.120 > 0.046 > - -

Burrows -0.098 > 0.093 > 0.099 > 0.345 > 0.281 > -0.084 >

59

Appendix 7. Pearson correlation coefficients (and p-values ≤0.05 in parentheses) for correlation of fork-tailed storm-petrel parameters and monthly

sea surface temperature anomaly at Seldovia, Alaska for the years 1997-2013. In the first table each month’s temperature anomaly is matched

year-for-year with the fork-tailed storm-petrel parameter index. The next two tables lag the fork-tailed storm-petrel indices by one and two years.

The final table advances the indices 1 year—the temperature anomalies are matched with the previous year’s fork-tailed storm-petrel indices.

Matched years 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan 0.154 -0.007 -0.101 0.000 -0.155 -0.044 0.161

Feb 0.254 -0.335 -0.408 -0.271 -0.215 0.224 0.017

Mar 0.235 -0.595 (0.019) -0.63 (0.012) -0.515 (0.049) -0.441 0.112 -0.209

Apr 0.425 -0.428 -0.513 -0.459 -0.376 0.242 -0.250

May 0.286 -0.301 -0.357 -0.301 -0.130 0.262 -0.251

Jun 0.106 -0.151 -0.184 -0.138 -0.073 0.162 -0.256

Jul -0.042 0.079 0.082 0.029 0.156 0.261 -0.379

Aug -0.112 0.331 0.264 0.069 -0.058 0.196 -0.454

Sep 0.095 0.496 0.378 0.154 -0.385 -0.038 -0.383

Oct 0.108 0.081 0.198 0.451 0.330 0.280 -0.069

Nov -0.162 -0.365 -0.285 -0.012 0.118 0.219 0.118

Dec -0.122 0.088 0.123 -0.061 -0.023 0.490 -0.158

Lag 1 year 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan -0.517 (0.048) 0.449 0.564 (0.029) 0.357 0.315 -0.011 0.079

Feb -0.378 0.404 0.482 0.321 0.051 -0.192 0.063

Mar -0.506 0.424 0.515 (0.049) 0.304 0.210 -0.065 -0.079

Apr -0.565 (0.028) 0.445 0.534 (0.040) 0.296 0.148 -0.342 -0.003

May -0.598 (0.019) 0.485 0.54 (0.038) 0.299 0.152 -0.449 -0.063

Jun -0.551 (0.033) 0.460 0.528 (0.043) 0.272 0.217 -0.278 -0.245

Jul -0.358 0.398 0.399 0.047 0.069 -0.331 -0.380

Aug -0.190 0.251 0.342 0.080 0.054 0.015 -0.668 (0.007)

Sep -0.132 0.185 0.295 0.090 0.204 0.382 -0.396

Oct -0.120 0.638 (0.010) 0.636 (0.011) 0.406 0.497 -0.093 0.120

Nov 0.343 -0.182 -0.249 -0.353 -0.517 (0.048) 0.214 -0.035

Dec 0.357 0.219 -0.002 -0.270 -0.253 0.106 -0.141

60

Appendix 7 (continued).

Lag 2 years 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan 0.126 0.112 -0.034 -0.127 -0.164 -0.331 -0.330

Feb -0.175 0.090 0.170 0.081 0.250 -0.035 -0.583 (0.022)

Mar -0.046 -0.023 -0.062 -0.194 0.158 0.016 -0.532 (0.041)

Apr 0.014 -0.133 -0.171 -0.277 -0.034 0.002 -0.617 (0.014)

May -0.019 0.078 0.057 -0.112 0.011 -0.003 -0.739 (0.002)

Jun -0.028 0.299 0.226 -0.057 -0.013 -0.192 -0.688 (0.005)

Jul -0.065 0.341 0.218 -0.206 -0.231 -0.168 -0.722 (0.002)

Aug 0.146 0.508 0.362 -0.092 0.007 -0.035 -0.515 (0.049)

Sep 0.494 0.213 0.021 -0.168 -0.153 -0.191 -0.042

Oct -0.244 0.436 0.376 0.266 0.060 -0.711 (0.003) -0.031

Nov -0.538 (0.038) 0.161 0.326 0.145 0.363 0.069 -0.121

Dec -0.817 (<0.001) 0.556 (0.031) 0.71 (0.003) 0.596 (0.019) 0.568 (0.027) -0.365 0.200

Advance 1 year 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan -0.406 -0.321 -0.267 -0.142 0.271 0.456 0.125

Feb -0.579 (0.030) 0.067 0.150 0.200 0.228 0.116 0.294

Mar -0.340 -0.077 -0.014 0.044 0.164 0.172 0.395

Apr -0.475 -0.114 0.068 0.263 0.308 0.190 0.345

May -0.572 (0.033) -0.017 0.176 0.288 0.284 0.130 0.377

Jun -0.59 (0.026) -0.102 0.053 0.123 0.213 0.108 0.334

Jul -0.569 (0.034) -0.085 0.078 0.096 0.076 0.151 0.041

Aug -0.644 (0.013) 0.100 0.204 0.077 0.147 -0.108 -0.065

Sep -0.500 -0.029 -0.007 -0.092 0.166 -0.081 -0.336

Oct -0.573 (0.032) 0.071 0.099 0.156 0.085 0.116 0.238

Nov -0.267 0.002 -0.117 -0.404 -0.400 -0.107 -0.004

Dec -0.279 0.372 0.193 -0.11 -0.126 -0.165 0.146

61

Appendix 8. Pearson correlation coefficients (and P-values in parentheses) for correlation of fork-tailed storm-petrel parameters and the monthly

Pacific Decadal Oscillation (PDO) index for the years 1997-2013. In the first table each month’s PDO index value is matched year-for-year with

the fork-tailed storm-petrel parameter index. The next two tables lag the fork-tailed storm-petrel indices by one and two years. The final table

advances the indices 1 year—the PDO indices are matched with the previous year’s fork-tailed storm-petrel indices.


Jan 0.098 0.313 0.232 0.150 -0.068 0.234 -0.085

Feb 0.288 0.040 -0.047 -0.105 -0.140 0.266 -0.318

Mar 0.250 -0.230 -0.292 -0.343 -0.260 0.279 -0.484

Apr 0.109 -0.051 -0.049 -0.036 0.045 0.197 -0.372

May -0.009 0.115 0.138 0.176 0.072 0.058 -0.353

Jun -0.103 0.235 0.244 0.170 -0.049 0.135 -0.536 (0.039)

Jul -0.150 0.452 0.466 0.204 0.009 0.207 -0.481

Aug -0.285 0.419 0.457 0.276 -0.047 0.207 -0.151

Sep -0.406 0.401 0.519 (0.047) 0.432 0.031 0.094 0.122

Oct -0.356 0.224 0.325 0.348 0.064 0.170 0.181

Nov -0.229 -0.021 0.066 0.068 -0.122 0.370 0.095

Dec -0.445 0.024 0.122 0.035 -0.030 0.298 -0.222


Jan -0.291 0.425 0.546 (0.035) 0.297 0.085 -0.088 -0.263

Feb -0.345 0.465 0.562 (0.029) 0.248 -0.031 -0.268 -0.302

Mar -0.337 0.356 0.405 0.014 -0.183 -0.181 -0.430

Apr -0.115 0.217 0.210 -0.122 -0.406 -0.378 -0.498

May -0.025 0.198 0.214 -0.060 -0.326 -0.038 -0.59 (0.021)

Jun 0.202 0.064 0.073 -0.083 -0.276 0.219 -0.483

Jul 0.221 -0.021 -0.062 -0.298 -0.356 0.190 -0.594 (0.019)

Aug 0.269 -0.129 -0.120 -0.218 -0.246 0.442 -0.517 (0.048)

Sep 0.367 -0.153 -0.168 -0.156 -0.213 0.545 (0.036) -0.405

Oct 0.243 0.001 0.022 0.137 0.065 0.306 -0.092

Nov 0.356 0.000 -0.035 0.002 -0.191 0.248 -0.003

Dec 0.272 0.222 0.077 -0.067 -0.176 0.194 -0.138

62



Jan 0.263 0.034 -0.054 -0.302 -0.148 -0.069 -0.699 (0.004)

Feb 0.243 -0.094 -0.146 -0.371 -0.177 0.207 -0.800 (<0.001)

Mar 0.052 -0.058 -0.102 -0.389 -0.137 0.304 -0.780 (0.001)

Apr -0.019 -0.101 -0.083 -0.351 -0.219 0.228 -0.806 (<0.001)

May 0.195 -0.048 -0.025 -0.236 -0.247 0.188 -0.739 (0.002)

Jun 0.214 0.059 0.102 -0.125 -0.236 0.151 -0.493

Jul 0.060 0.157 0.199 -0.077 -0.224 0.117 -0.539 (0.038)

Aug -0.064 0.373 0.451 0.166 0.087 -0.103 -0.414

Sep -0.075 0.274 0.424 0.299 0.027 -0.158 -0.308

Oct -0.079 0.232 0.364 0.252 -0.068 -0.226 -0.355

Nov -0.307 0.052 0.252 0.220 0.152 -0.157 -0.230

Dec -0.518 (0.048) 0.357 0.535 (0.040) 0.391 0.259 -0.165 -0.101

Advance 1 yr 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan -0.555 (0.039) -0.063 0.014 0.091 0.196 0.252 -0.077

Feb -0.646 (0.012) 0.140 0.308 0.367 0.315 0.174 -0.025

Mar -0.608 (0.021) 0.110 0.270 0.220 0.204 0.147 -0.002

Apr -0.563 (0.036) 0.146 0.341 0.429 0.312 0.147 0.115

May -0.621 (0.018) 0.240 0.374 0.370 0.397 0.145 0.105

Jun -0.751 (0.002) 0.379 0.449 0.319 0.180 -0.273 -0.103

Jul -0.646 (0.013) 0.313 0.351 0.158 -0.011 -0.107 -0.294

Aug -0.474 0.129 0.039 -0.210 -0.248 -0.104 -0.123

Sep -0.198 0.167 -0.018 -0.230 -0.252 -0.069 0.056

Oct -0.237 0.087 -0.027 -0.031 -0.252 -0.180 0.243

Nov -0.184 0.133 -0.042 -0.064 -0.238 -0.208 0.365

Dec -0.331 0.300 0.100 -0.149 -0.278 -0.511 0.222

63

Appendix 9. Pearson correlation coefficients (and P-values in parentheses) for correlation of fork-tailed storm-petrel parameters and the monthly

North Pacific (NP) index for the years 1997-2013. In the first table each month’s NP index value is matched year-for-year with the fork-tailed

storm-petrel parameter index. The next two tables lag the fork-tailed storm-petrel indices by one and two years. The final table advances the

indices 1 year—the NP indices are matched with the previous year’s fork-tailed storm-petrel indices.


Jan -0.405 0.065 0.130 -0.076 0.222 -0.218 -0.200

Feb -0.118 0.405 0.432 0.498 0.188 -0.301 0.242

Mar -0.581 (0.023) 0.534 (0.040) 0.585 (0.022) 0.513 0.275 -0.111 0.355

Apr 0.040 -0.405 -0.359 -0.220 -0.199 0.153 0.083

May 0.170 -0.166 -0.160 -0.156 0.297 0.149 0.258

Jun 0.168 -0.175 -0.290 -0.404 -0.257 -0.163 -0.218

Jul 0.428 -0.474 -0.468 -0.193 -0.068 0.206 0.079

Aug 0.357 -0.399 -0.428 -0.399 -0.070 0.673 (0.006) -0.259

Sep -0.445 0.373 0.430 0.138 0.169 -0.068 -0.55 (0.034)

Oct 0.308 -0.008 -0.164 -0.479 -0.552 (0.033) -0.334 -0.453

Nov 0.285 0.119 0.170 0.366 0.276 -0.173 0.037

Dec 0.365 -0.103 -0.144 -0.040 -0.131 -0.032 0.405


Jan 0.268 -0.117 -0.363 -0.369 -0.214 0.031 0.155

Feb -0.039 0.240 0.226 0.300 0.392 0.235 0.321

Mar 0.375 -0.241 -0.159 0.246 0.343 0.451 0.071

Apr -0.087 0.101 0.134 0.198 0.52 (0.047) 0.114 0.456

May -0.134 0.103 0.015 0.082 0.053 -0.416 0.567 (0.028)

Jun -0.022 0.224 0.246 0.146 -0.245 -0.014 -0.138

Jul -0.389 -0.109 -0.003 0.004 0.127 -0.463 0.267

Aug 0.097 0.214 0.120 0.056 -0.256 -0.300 0.464

Sep -0.242 0.462 0.435 0.284 0.287 -0.297 -0.474

Oct -0.154 -0.132 -0.077 -0.194 -0.117 0.139 -0.288

Nov -0.330 0.335 0.417 0.391 0.476 -0.412 0.112

Dec 0.263 -0.427 -0.278 0.008 -0.134 0.060 0.123

64



Jan -0.181 -0.085 -0.018 0.138 0.008 0.265 0.556 (0.031)

Feb 0.335 -0.044 -0.056 0.181 -0.188 -0.487 0.333

Mar 0.283 0.175 0.164 0.124 -0.147 -0.231 0.275

Apr -0.250 0.165 0.036 0.039 0.079 -0.411 0.525 (0.045)

May 0.035 -0.538 (0.039) -0.498 -0.341 -0.393 0.050 -0.124

Jun 0.343 -0.452 -0.441 -0.394 0.017 0.681 (0.005) -0.185

Jul 0.077 -0.364 -0.512 -0.538 (0.038) -0.391 -0.027 -0.256

Aug 0.085 -0.605 (0.017) -0.492 -0.418 -0.435 0.389 -0.239

Sep 0.069 0.232 0.109 -0.204 0.145 0.003 -0.260

Oct 0.526 (0.044) -0.438 -0.595 (0.019) -0.537 (0.039) -0.273 0.571 (0.026) 0.043

Nov 0.322 -0.056 -0.136 -0.022 -0.258 -0.220 -0.380

Dec 0.305 -0.528 (0.043) -0.527 (0.044) -0.303 0.177 0.301 0.148


Jan 0.405 0.228 0.090 -0.157 -0.276 -0.354 -0.368

Feb 0.007 -0.133 -0.219 -0.110 0.087 -0.039 0.012

Mar 0.357 -0.121 -0.294 -0.328 -0.471 -0.277 -0.242

Apr 0.292 -0.331 -0.447 -0.402 -0.321 0.037 0.095

May 0.387 -0.352 -0.267 -0.045 -0.270 0.300 -0.280

Jun 0.010 0.335 0.349 0.260 0.290 -0.032 -0.353

Jul 0.066 -0.524 -0.331 0.014 0.019 0.409 0.290

Aug -0.196 0.078 0.161 0.190 -0.063 -0.185 -0.058

Sep -0.045 0.156 0.113 -0.010 -0.212 -0.512 -0.083

Oct 0.156 0.058 0.149 0.165 0.291 0.101 -0.502

Nov -0.285 0.131 0.336 0.66 (0.01) 0.487 0.366 0.264

Dec 0.470 -0.039 -0.019 0.173 0.125 0.367 -0.042

65

Appendix 10. Pearson correlation coefficients (and P-values in parentheses) for correlation of fork-tailed storm-petrel parameters and monthly

precipitation anomaly at Kitoi Bay, Afognak Island, Alaska for the years 1997-2013. In the first table each month’s precipitation anomaly is

matched year-for-year with the fork-tailed storm-petrel parameter index. The next two tables lag the fork-tailed storm-petrel indices by one and

two years. The final table advances the indices 1 year—the precipitation anomalies are matched with the previous year’s fork-tailed storm-petrel

indices.


Jan -0.064 -0.085 -0.189 -0.310 -0.594 (0.032) 0.173 -0.037

Feb -0.386 0.226 0.175 -0.112 -0.316 0.183 -0.272

Mar 0.227 -0.528 (0.043) -0.575 (0.025) -0.705 (0.003) -0.593 (0.02) 0.168 -0.513

Apr 0.154 0.132 -0.015 -0.438 -0.335 -0.227 -0.538

May 0.265 0.073 0.042 -0.150 -0.334 -0.090 -0.419

Jun 0.099 -0.144 -0.007 -0.162 -0.174 0.108 -0.567 (0.034)

Jul 0.006 -0.034 0.017 -0.079 -0.011 0.160 -0.315

Aug 0.195 -0.034 -0.037 0.113 0.064 -0.255 0.246

Sep 0.250 -0.027 0.012 0.092 -0.414 -0.389 0.067

Oct -0.099 -0.198 -0.095 0.079 0.361 0.821 (0.001) 0.112

Nov -0.406 0.051 0.163 0.106 0.229 0.149 0.161

Dec -0.293 0.190 0.109 -0.226 -0.147 -0.571 (0.033) -0.614 (0.02)


Jan -0.078 -0.187 -0.006 0.003 0.110 0.661 (0.014) -0.324

Feb 0.035 0.143 0.242 0.168 0.160 0.354 -0.563 (0.036)

Mar -0.420 0.370 0.383 0.207 0.495 0.254 0.194

Apr -0.147 0.069 -0.059 -0.369 -0.483 0.046 -0.367

May -0.078 0.188 0.168 -0.012 0.048 0.039 -0.329

Jun -0.140 0.459 0.311 -0.150 0.003 -0.163 -0.246

Jul 0.166 0.173 0.092 0.202 0.302 0.302 0.259

Aug -0.449 0.220 0.250 0.124 0.404 0.002 0.336

Sep 0.227 -0.416 -0.303 -0.124 0.175 0.609 (0.016) -0.056

Oct 0.016 0.190 0.057 -0.115 0.034 0.128 0.377

Nov 0.523 -0.490 -0.65 (0.012) -0.651 (0.012) -0.474 0.159 -0.078

Dec -0.284 0.311 0.187 -0.197 -0.162 0.092 -0.508

66



Jan 0.098 0.277 0.168 -0.138 -0.058 -0.218 -0.113

Feb -0.221 0.736 (0.003) 0.702 (0.005) 0.318 0.354 -0.031 -0.254

Mar 0.052 -0.062 -0.164 -0.143 0.096 0.066 0.147

Apr 0.246 -0.327 -0.235 -0.126 -0.022 0.788 (0.001) -0.247

May 0.130 -0.159 -0.171 -0.090 0.277 -0.091 0.163

Jun -0.210 -0.470 -0.470 -0.429 -0.213 -0.072 -0.388

Jul 0.315 -0.304 -0.209 0.001 -0.110 0.118 0.336

Aug 0.143 -0.168 -0.277 -0.192 -0.454 -0.473 -0.101

Sep 0.461 -0.450 -0.482 -0.204 -0.171 -0.151 0.293

Oct -0.439 0.353 0.428 0.366 0.033 -0.359 0.135

Nov -0.518 0.182 0.216 0.107 0.255 -0.164 0.549 (0.042)

Dec -0.007 0.442 0.396 0.226 0.022 0.409 -0.216


Jan -0.037 -0.59 (0.043) -0.728 (0.007) -0.828 (0.001) -0.668 (0.018) -0.057 -0.213

Feb -0.362 0.323 0.199 -0.059 -0.088 -0.308 0.097

Mar -0.107 -0.011 -0.089 -0.308 -0.302 -0.203 -0.179

Apr -0.244 0.357 0.410 0.137 0.216 -0.093 -0.542

May -0.054 0.234 0.220 0.159 0.126 -0.224 -0.143

Jun -0.095 0.189 0.122 0.141 -0.104 0.141 -0.123

Jul 0.100 0.267 0.140 -0.103 -0.426 -0.59 (0.026) -0.273

Aug -0.017 -0.547 (0.043) -0.461 -0.198 0.006 0.606 (0.022) -0.179

Sep 0.340 -0.125 -0.164 0.065 0.076 0.169 -0.054

Oct -0.309 -0.139 -0.229 -0.493 -0.492 -0.018 -0.101

Nov 0.477 -0.231 -0.389 -0.556 (0.049) -0.528 0.010 -0.214

Dec -0.406 0.392 0.409 0.090 0.269 -0.201 -0.319

67

Appendix 11. In this table the annual groups of fork-tailed storm-petrel parameters were first placed in random order relative to the years, as a test of the

exploratory correlation method. Pearson correlation coefficients (and P-values in parentheses) for correlation of fork-tailed storm-petrel parameters and monthly

sea surface temperature anomaly at Seldovia, Alaska for the years 1997-2013. In the first table each month’s temperature anomaly is matched year-for-year with

the fork-tailed storm-petrel parameter index. The next two tables lag the fork-tailed storm-petrel indices by one and two years. The final table advances the

indices 1 year—the temperature anomalies are matched with the previous year’s fork-tailed storm-petrel indices.


Jan -0.335 -0.162 -0.118 0.044 0.254 -0.045 0.038

Feb -0.517 (0.048) 0.142 0.207 0.333 0.161 -0.189 0.225

Mar -0.496 -0.022 0.161 0.421 0.324 -0.124 0.265

Apr -0.535 (0.040) 0.090 0.234 0.372 0.177 -0.188 0.060

May -0.407 -0.062 0.106 0.325 0.021 -0.056 -0.112

Jun -0.264 -0.221 -0.065 0.192 -0.055 -0.023 -0.145

Jul -0.186 -0.250 -0.163 -0.026 -0.142 0.041 -0.229

Aug 0.069 -0.418 -0.314 -0.086 -0.339 0.047 -0.270

Sep 0.033 -0.230 -0.168 -0.066 -0.043 0.116 -0.249

Oct -0.356 0.234 0.274 0.203 0.171 0.236 -0.306

Nov -0.210 0.060 -0.027 -0.065 0.066 -0.036 0.377

Dec -0.106 0.037 0.001 -0.158 -0.506 -0.246 -0.405


Jan -0.032 0.115 0.069 -0.027 -0.106 -0.174 0.047

Feb -0.034 -0.218 -0.154 -0.042 0.103 -0.175 0.226

Mar 0.115 -0.266 -0.379 -0.527 (0.044) -0.440 -0.536 (0.040) -0.051

Apr 0.325 -0.303 -0.434 -0.541 (0.037) -0.397 -0.442 0.284

May 0.381 -0.228 -0.309 -0.316 -0.244 -0.401 0.256

Jun 0.292 -0.114 -0.219 -0.304 -0.270 -0.335 0.205

Jul 0.230 -0.059 -0.067 -0.032 -0.096 -0.206 0.241

Aug 0.032 0.185 0.153 -0.012 0.034 -0.040 0.094

Sep -0.048 0.376 0.220 -0.192 -0.201 -0.048 0.014

Oct 0.174 0.077 0.043 -0.015 -0.121 -0.078 -0.079

Nov -0.639 (0.010) -0.185 0.018 0.229 0.246 -0.116 0.175

Dec -0.370 -0.019 0.162 0.382 0.156 -0.064 -0.167

68



Jan -0.003 -0.308 -0.184 0.041 -0.439 0.095 -0.156

Feb 0.157 -0.370 -0.373 -0.401 -0.658 (0.008) 0.246 -0.388

Mar 0.161 -0.376 -0.436 -0.346 -0.264 0.433 0.229

Apr 0.186 -0.492 -0.513 -0.362 -0.332 0.620 (0.014) 0.197

May 0.283 -0.404 -0.493 -0.487 -0.438 0.509 0.099

Jun 0.346 -0.428 -0.481 -0.402 -0.363 0.521 (0.047) 0.152

Jul 0.372 -0.468 -0.497 -0.398 -0.399 0.288 0.082

Aug 0.239 -0.273 -0.265 -0.242 -0.168 0.253 -0.187

Sep -0.012 -0.211 0.010 0.337 0.376 0.464 -0.119

Oct 0.808 (<0.001) -0.446 -0.431 -0.143 -0.338 0.606 (0.017) 0.039

Nov 0.145 -0.274 -0.314 -0.396 -0.54 (0.038) -0.358 -0.159

Dec 0.618 (0.014) -0.058 -0.225 -0.336 -0.385 -0.126 0.117

Advance 1 year 20-mm Date Chicks Large chicks Lg chicks/chks Wing growth Mass gain Burrows

Jan 0.286 0.092 0.090 0.124 0.219 -0.059 0.316

Feb 0.077 0.193 0.298 0.514 0.548 (0.042) -0.043 0.233

Mar 0.112 -0.111 -0.007 0.281 0.310 0.014 0.418

Apr -0.091 0.105 0.213 0.435 0.558 (0.038) -0.170 0.399

May -0.009 0.084 0.151 0.323 0.482 0.070 0.419

Jun 0.095 0.065 0.115 0.273 0.350 0.102 0.430

Jul 0.025 0.116 0.094 0.106 0.313 0.163 0.244

Aug 0.269 0.069 0.083 0.187 0.272 0.194 0.167

Sep 0.202 0.200 0.192 0.137 0.028 -0.328 -0.156

Oct 0.030 0.436 0.416 0.359 0.251 0.028 0.125

Nov 0.211 -0.442 -0.347 0.015 -0.020 0.260 -0.040

Dec 0.081 -0.201 -0.101 0.132 -0.125 0.707 (0.005) -0.218

69

Appendix 12. Correlation plot of sea surface temperature and the Pacific Decadal Oscillation monthly index. Plot created with this website: Earth Systems Research Laboratory, Physical Sciences Division, < http://www.esrl.noaa.gov/psd/data/correlation/>.

Jan to Dec: 1948 to 2011 Surface SST Seasonal Correlation w/ Jan to Dec PDO

NCEP/NCAR Reanalysis

NOM/ESRL Physical Sciences Division

70

Appendix 13. Correlation plot of sea surface temperature and the North Pacific monthly index. Plot created with this website: Earth Systems Research Laboratory, Physical Sciences Division, < http://www.esrl.noaa.gov/psd/data/correlation/>.

Jan to Dec: 1948 to 2011 Surface SST Seasonal Correlation w/ Jan to Dec NP

NCEP/NCAR Reanalysis

NOM/ESRL Physical Sciences Division

-0.1

-0.3

-0.5

-0.7

0.7

0.5

0.3

0.1

71

Appendix 14. Field crew members (Biological Science Technicians and volunteers) at East Amatuli Island, Alaska during fork-tailed storm-petrel

monitoring years 1997-2013. ABK was present as the field team leader each year.

Year Field crew

1997 Stephanie Zuniga Lena Wilensky John Hoover Margi Blanding

1998 Stephanie Zuniga Gavin Brady Tammy Steeves Margi Blanding

1999 Erica Sommer Jessica Bussler Chris Wrobel Margi Blanding

2000 Courtney Redmond Kyra Riley Darren Moe Julie Snorek

2001 Jessica Bussler Mari Ortwerth Michelle Wada

2002 Rachael Orben Greg Thomson Amie Baton

2003 Kelly Wallis Michelle Schuiteman Jeremy Mizel

2004 Wendy Fair Valerie Steen Marcy Okada

2005 Joshua Boadway Kelly Boadway Laura Kennedy

2006 Kathryn Peiman Emily Weiser Megan McClellan

2007 Trevor Watts Meaghan Conway Leah Yandow

2008 Emily McKeever Gina Peters Kathryn Frens

2009 Amy Kearns Kristina Raum Frank Mayer

2010 Sarah Bastarache Abram Fleishman Sarah Youngren

2011 Sarah Youngren Margaret Lambert Dan Rapp

2013 Sonia Kumar Serina Brady Charles Ylijoki

Documents

Fork-tailed storm-petrel monitoring at East Amatuli Island ...AMNWR 2014/10 FORK-TAILED STORM-PETREL MONITORING AT EAST AMATULI ISLAND, ALASKA DURING 1997-2013 Arthur B. Kettle Key