BIOLOGICAL MONITORING AT CHOWIET ISLAND, ALASKA IN 2007: SUMMARY APPENDICES

Transcription

1 BIOLOGICAL MONITORING AT CHOWIET ISLAND, ALASKA IN 27: SUMMARY APPENDICES AMNWR 7/9 Joel A. Helm Tyra A. Zeman Key Words: Aethia psittacula, black-legged kittiwake, Cerorhinca monocerata, Chowiet Island, common murre, food habits, Fratercula cirrhata, Fratercula corniculata, Fulmarus glacialis, glaucous-winged gull, growth rates, horned puffin, Larus glaucescens, northern fulmar, population size, parakeet auklet, productivity, rhinoceros auklet, Rissa tridactyla, Semidi Islands, thick-billed murre, tufted puffin, Uria aalge, Uria lomvia. U.S. Fish and Wildlife Service Alaska Maritime National Wildlife Refuge 95 Sterling Hwy., Suite 1 Homer, Alaska 9963 October 27 Cite as: Helm, Joel A. and Tyra A. Zeman. 27. Biological monitoring at Chowiet Island, Alaska in 27: summary appendices. U.S. Fish and Wildl. Serv. Rep. AMNWR 7/9. Homer, AK. 84 pp.

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3 TABLE OF CONTENTS INTRODUCTION...1 STUDY AREA...1 METHODS...2 INTERESTING OBSERVATIONS...2 ACKNOWLEDGMENTS...2 REFRENCES...3 MAPS...6 FIGURES AND TABLES...8 Northern fulmars...9 Populations...9 Glaucous-winged gulls...12 Breeding chronology...12 Reproductive performance...14 Populations...16 Food habits...17 Black-legged kittiwakes...19 Breeding chronology...19 Reproductive performance...21 Populations...24 Thick-billed murres...28 Breeding chronology...28 Reproductive performance...3 Populations...33 Food habits...44 Common murres...36 Breeding chronology...36 Reproductive performance...38 Populations...41 Food habits...44 Parakeet auklets...45 Breeding chronology...45 Reproductive performance...47 Populations...49 Rhinoceros auklets...52 Breeding chronology...52 Reproductive performance...54 Populations...56 Food habits...57 Horned puffins...6 Breeding chronology...6 Reproductive performance...62 Populations...64 Tufted puffins...67 Breeding chronology...67 Reproductive performance...69 Miscellaneous...72 Off-road point count...71 Beach passerine transects...74 Sea surface temperatures...76 Annotated list...79

4 INTRODUCTION In 22, the Alaska Maritime National Wildlife Refuge (AMNWR) established an annual ecological monitoring site at the Semidi Islands, where various seabird projects have taken place since Seabird species selected for annual monitoring were chosen based on their ability, across the refuge, to serve as indicators of fluctuations in the marine food web. Major projects include monitoring population trends and the breeding success of piscivores and planktivores - both diving and surface feeders. Goals in 27 were to estimate population and/or reproductive parameters for 9 species as indicators of the 4 major feeding guilds: surface fish-feeders (black-legged kittiwakes, Rissa tridactyla), diving fish-feeders (common and thick-billed murres, Uria aalge and U. lomvia, respectively; tufted and horned puffins, Fratercula cirrhata and F. corniculata, respectively; and rhinoceros auklets, Cerorhinca monocerata), surface plankton-feeders (northern fulmars, Fulmarus glacialis), and diving plankton-feeders (parakeet auklets, Aethia psittacula). Diets of glaucous-winged gulls (regurgitated pellets) and rhinoceros auklets (chick meals) were sampled as well. Detailed results from 27 are summarized and contained in these appendices and archived at the Refuge headquarters in Homer, Alaska. For comparisons among years, we present selected historic data sets from 1976 to 1991 (Baggot et al. 1989, Dragoo et al. 1991a and 1991b, Hatch and Hatch 198, 1981, 1983 and Leschner and Burrell 1977), unpublished data from 1993 and 1994 (Hatch unpubl. data) and data from 1995, 1998 (Nevins and Adams 1999), 21 (Hatch unpubl. data), 22 (Wang 22), 24 (Larned 24), 25 (Larned and Sapora 25) and 26 (Fairchild et al. 27). This report supersedes previous reports; in some cases data have been reanalyzed to fix inconsistencies. The following historical data appearing in this report have been amended: Rhinoceros auklet hatching and fledging chronology 22 Glaucous-winged gull food habits Murre hatching chronology 22, 26 Tufted puffin productivity 26 STUDY AREA The Semidi Islands group (N W ) consists of nine islands located on the continental shelf approximately 8 km south of the Alaska Peninsula and 16 km southwest of Kodiak Island. Local oceanography is influenced by the Alaskan Coastal Current and the Alaska Stream (Hatch and Hatch 1983a, Hatch and Hatch 1989). Approximately 2.4 million seabirds consisting of twenty species, an estimated 25% of the total seabird biomass in the Gulf of Alaska, breed in the Semidis (Hatch and Hatch 1983a). A small population of Cackling geese (Branta hutchinsii) breeds on Kaliktagik and Anowik Islands (Hatch and Hatch 1983b). The seabird population supports many avian predator species which also breed in the Semidis, including the bald eagle, (Haliaeetus leucocephalus), peregrine falcon (Falco peregrinus), glaucous-winged gull (Larus glaucescens), and common raven (Corvus corax). Dominant vegetation includes umbelliferous roots, beach rye-grasses, ferns, herbs and is classified as Alaskan maritime (Hatch 1985). Shorelines are generally precipitous; the highest elevation is approximately 3 m with sheer cliffs rising more than 2 m in many areas of the islands (Hatch and Hatch 1983b). All islands are treeless except for Chowiet Island, which has a small number (<1) of Sitka spruce (Picea sitchensis), most likely introduced by fox ranchers in the early 19s. Fox ranching occurred on Chowiet and Aghiyuk Islands from 1885 to about 1914 (Bower and Aller 1917), after which the natural die off of the introduced artic and red foxes (Alopex lagopus and Vulpes fulva, respectively) took place (Hatch and Hatch 1983b). The only land mammals that presently exist on the islands are arctic ground squirrels (Spermophilus parryii) and they occur on all of the Semidi Islands except for South, Suklik and Aghik (Hatch and Hatch 1983b). 1

5 METHODS Personnel : Joel Helm and Tyra Zeman were present on Chowiet Island from 2 May through 3 September, 27. Data collection and analysis: Data collection methods are outlined in the 25 protocols (Larned and Sapora 25), which are taken from 22 Summary Appendices (Wang 22), and originally modified from Williams et al. (2). Exceptions and additions to those protocols follow: Rhinoceros auklet productivity was not measured this year due to significant erosion in the South Bay colony. Common murre prey items were not identified due to time constraints and observer inexperience. Rhinoceros auklet food collection was completed during three nights of mist netting, yielding 12 food loads consisting of Pacific sandlance and Hexagrammids. INTERESTING OBSERVATIONS Two red-faced cormorants were monitored on black-legged kittiwake plots A2B1 and A2B2. Another breeding group (53 nests) was discovered 2 miles from camp on the southeastern portion of the island. Birds nested in small coves north of Puffin Point. Three pelagic cormorant nests were found in close proximity to the congregation of red-faced cormorants and those nests were followed to determine nest fate. The first red-faced cormorant chick was sighted on 27 June. The majority of chicks had fledged prior to field personnel leaving the island. A breakdown of nesting information is as follows: Nests with chicks Total chicks Red-faced cormorant Pelagic cormorant 3 9 These nests were found late in the season and should not be used for time-series productivity estimates. ACKNOWLEDGEMENTS The crew of the M/V Tiĝlaˆx provided safe transport to Chowiet in 27 for crew and supplies. Special thanks are extended to the refuge staff in Homer and Adak who assisted field staff in the compilation of this report and the collection of field data throughout the season. Heather Renner s advice regarding data collection and analysis were greatly appreciated throughout this season and summary process. 2

6 REFERENCES Baggot, C.M., B.K. Bain and D.R. Nysewander Changes in colony size, and reproductive success of seabirds at the Semidi Islands, Alaska, U.S. Fish and Wildl. Serv. Rep., Homer, AK. Bower, W.T. and H.D. Aller Alaska fisheries and fur industries in Dept. of Commerce, Bureau of Commercial Fisheries, U.S. Gov t. Printing Office. Dragoo, D.E., B.K. Bain and A. Perillo. 1991a. Changes in colony size and reproductive success of seabirds at the Semidi Islands, Alaska, U.S. Fish and Wildl. Serv. Rep., Homer, AK. Dragoo, D.E., B.K. Bain, M.J. Melendez and C.M. Minch. 1991b. Changes in colony size and reproductive success of seabirds at the Semidi Islands, Alaska, U.S. Fish and Wildl. Serv. Rep., Homer, AK. Evans, D.H., J.B. Claiborne and G.A. Kormanik, Osmoregulation, acid-base regulation, and nitrogen excretion. p In M.H. Horn, K.L.M. Martin and M.A. Chotkowski (eds.). Intertidal fishes live in two worlds. Academic Press, San Diego, CA. Fairchild, L., Mischler, C. and H.M. Renner. 27. Biological monitoring on Chowiet Island in 26: summary appendices. U.S. Fish and Wildl. Serv. Rep. AMNWR 7/2. Homer, AK. Hatch, M.A Vegetation and flora of the Semidi Islands, Alaska. Unpubl. M.S. thesis, Univ. of Alaska, Fairbanks, AK. Hatch, S.A Adult survival and productivity of northern fulmars in Alaska. Condor 89: Hatch, S.A. and M.A. Hatch Breeding and population ecology of seabirds at Semidi Islands, Alaska. U.S. Fish and Wildl. Serv. Rep., Anchorage, AK. Hatch, S.A and M.A. Hatch Breeding and population ecology of seabirds at Semidi Islands, Alaska. U.S. Fish and Wildl. Serv. Rep., Anchorage, AK. Hatch, S.A and M.A. Hatch Populations and habitat use of marine birds in the Semidi Islands, Alaska. Murrelet 64: Larned, A. L. 24. Results of seabird monitoring at Chowiet Island in 24: Summary Appendices. U.S. Fish and Wildl. Serv. Rep. AMNWR 4/1. Homer, AK. Larned, A. L. and S. F. Sapora 25. Results of seabird monitoring at Chowiet Island in 25: summary appendices. U.S. Fish and Wildl. Serv. Rep. AMNWR 5/15. Homer, AK. Leschner, L.L. and G. Burrell Populations and ecology of marine birds on the Semidi Islands. U.S. Fish and Wildl. Serv. Rep., Anchorage, AK. Martin, K.L.M. and C.R. Bridges, Respiration in water and air. p In M.H. Horn, K.L., M. Martin and M.A. Chotkowski (eds.) Intertidal fishes. Life in two worlds. Academic Press. 399 p. Nevins, H.M. and J. Adams Seabird monitoring in the Semidi Islands, Gulf of Alaska, 1995 and U.S. Fish and Wildl. Serv. Rep. AMNWR 98/17. Homer, AK. 3

7 Wang, S.W. 22. Results of seabird monitoring at Chowiet Island, Alaska in 22: Summary Appendices. U.S. Fish and Wildl. Serv. Rep., AMNWR 2/7. Homer, AK. Williams, J.C., L. Scharf, and G.V. Byrd. 2. Ecological monitoring methods of the Aleutian Islands Unit, Alaska Maritime National Wildlife Refuge. U.S. Fish and Wildl. Serv. Rep., AMNWR /1. Adak, AK. 4

8 Figure 1. Location of the Semidi Islands in the Western Gulf of Alaska. 6

9 Figure 2. Map of Chowiet Island, Alaska. 7

10 DATA SUMMARIES 8

11 Adults Chicks Figure 3. Mean number of northern fulmar adults and maximum number of chicks counted at Chowiet Island, Alaska. 9

12 Table 1. Northern fulmar population index counts and breeding chronology at Chowiet Island, Alaska. bc Mean no. Max. no. First lay Last lay First hatch Years of adults SD n of chicks n date date mean SD n date mean SD n May 23 Jun 6 Jun Jul Jun 22 Jun 11 Jun Jul May 2 Jun 7 Jun Jul Jun 24 Jun 11 Jun 4 29 Jul May 2 Jul 8 Jun Jul May 25 Jun 1 Jun Jul Jun 5 Jul 15 Jun Jul 3 Jul May 19 Jun 6 Jun Jul 24 Jul Jun 15 Jun 91 1 Aug Jun - 15 Jun Jul 31 Jul Jun Jul Jun a Jul May Jul Jun Jun a a Formal productivity surveys were not conducted so lay/hatch dates are only incidental observations. b Data were not collected in , 1992, 1994, , , and 23. c (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 1

13 Table 2. Counts of northern fulmar adults on index plots at Chowiet Island, Alaska, in 27. Dates Statistics Plot 17 Jun 19 Jun 24 Jun 26 Jun 3 Jun 2 Jul 4 Jul 5 Jul 9 Jul 1 Jul Mean SD Max A3N A4N A7N A1N A1N A12N A12N Totals Table 3. Counts of northern fulmar chicks on index plots at Chowiet Island, Alaska, in 27. Dates Statistics Plot 28 Aug 29 Aug 31 Aug 2 Sep Mean SD Max A3N A4N A7N A1N A1N2 A12N A12N Totals

14 Table 4. Breeding chronology of glaucous-winged gulls at Chowiet Island, Alaska. cd Mean Median Total First Last Year hatch SD n a hatch nests b hatch hatch e Jun Jun 3 22 Jun 3 Jul 25 5 Jul Jul Jun 15 Jul 26 e Jul Jul 3 1 July 11July a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in 1977, , , and d (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. e Productivity data was collected using boom-bust methodology and chronology data was not collected. 12

15 Table 5. Frequency distribution of hatch dates for glaucous-winged gulls at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ac Date n = a Data were not collected in 1977, , , and b Nests were visited on a 1 day interval. c (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 13

16 Table 6. Reproductive performance of glaucous-winged gulls at Chowiet Island, Alaska. Measures of success are based on nests as the sample unit. bc Parameter No. nests (A) a No. nests 1 egg (B) No. eggs (C) No. nests 1 chick (D) No. chicks (E) Laying success (B/A) Clutch size (C/B) Nesting success (D/B) Hatching success (E/C) a Represents maximum number of nests counted during the season. b Data were not collected in 1977, , , and 23. c (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 14

17 Table 7. Reproductive performance of glaucous-winged gulls at Chowiet Island, Alaska, in 27. Measures of success are based on nests as the sample unit. Sub-colony Parameter A B C TOTAL No. nests (A) a No. nests 1 egg (B) No. eggs (C) No. nests 1 chick (D) No. chicks (E) Laying success (B/A) Clutch size (C/B) Nesting success (D/B) Hatching success (E/C) a Represents maximum number of nests counted during the season. 15

18 25 2 Max. no. of nests Figure 4. Maximum number of glaucous-winged gull nests counted on sub-colonies A, B, and C at Chowiet Island, Alaska. 16

19 Table 8. Occurrence of food items (%) in regurgitated pellets of glaucous-winged gulls at Chowiet Island, Alaska. a Food item Sample size Invertebrates Sea urchin Blue mussel Snail Limpet Chiton Crab Clam Unid. Shellfish Bryozoans Fish Unid. fish Birds Parakeet auklet Unid. Murre Horned puffin Rhinocerus auklet Northern fulmar Unid. bird Passerine Glaucous-winged gull egg Northern fulmar egg Murre egg Unid. egg Mammals Arctic ground squirrel Miscellaneous Terrestrial vegetation Unid. Kelp Rocks Unknown insect a Data were not collected in

20 Table 9. Percent volume of food in regurgitated pellets of glaucous-winged gulls at Chowiet Island, Alaska, a Food item Sample size Invertebrates Sea urchin Blue mussel Snail Limpet Chiton Crab Clam Unid. shellfish Bryozoans Fish Unid. fish Birds Parakeet auklet Unid. Murre Horned puffin Rhinocerus auklet Northern fulmar Unid. bird Passerine Glaucous-winged gull egg Northern fulmar egg Murre egg Unid. egg Mammals Arctic ground squirrel Miscellaneous Terrestrial vegetation Unid. kelp Rocks Unknown insect a Data were not collected in

21 Table 1. Breeding chronology of black-legged kittiwakes at Chowiet Island, Alaska. cd Mean Median No. of nests First Last First Last First Year hatch SD n a hatch monitored b lay lay hatch hatch fledge Jul 1 Jun 3 Jun 7 Jul 4 Aug 2 Aug Jul 9 Jun 3 Jun Jul 5 Jun 27 Jun Jul 17 Jun 9 Jul Jul 5 Jun 3 Jul Jul 5 Jun 5 Jul Jun 7 Jul Jul 4 Jun 29 Jun 3 Jul 24 Jul 15 Aug Jul 3 23 Jun 5 Jul Jun 8 Jul Jul 7 19 Jun 18 Jul 2 Jul 4 Aug 22 8 Jul Jul 1 Jun 28 Jun 28 Jun 25 Jul 1 Aug Jul Jul 8 Jun 26 Jun 4 Jul 24 Jul 11 Aug Aug Jul 27 Jun 14 Jul 24 Jul 12 Aug > 4 Sep Jul Jul 9 Jun 6 Jul 7 Jul 29 Jul 18 Aug Jul Jul 237 <19 Jun 1 Jul 13 Jul 6 Aug 26 Aug a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in , , , , and 23. d () = data collected/potentially collected but not compiled as of print date. 19

22 Table 11. Frequency distribution of hatch dates for black-legged kittiwakes at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ab Date n = a Data were not collected in , , , , and 23. b () = data collected/potentially collected but not compiled as of print date. 2

23 1% 9% 8% 7% Percent of nest sites 6% 5% 4% 3% Laying failure Egg Loss Chick loss Productivity 2% 1% % Figure 5. Reproductive performance of black-legged kittiwakes at Chowiet Island, Alaska. Laying Failure=(A-B)/A; Egg Loss=(B-C)/A; Chick Loss=(C-D)/A; Productivity=D/A, where A=total number of nests; B=number of nests with 1 egg; C=number of nests with 1 chick; D=number of nests with 1 fledged chick. 21

24 Table 12. Reproductive performance of black-legged kittiwakes at Chowiet Island, Alaska. ab Total Mean No. nests No. nests No. nests Laying Nesting Fledging Reprod. nests clutch w/eggs w/chicks w/fledged chick success success success success Prod. Year (A) (B) (D) (F) (B/A) (D/B) (F/D) (F/B) (F/A) a Data were not collected in , 1992, , , and 23. b (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 22

25 Table 13. Reproductive performance of black-legged kittiwakes at Chowiet Island, Alaska, in 27. Plots Statistics a P6B1 Total n mean SD Parameter P3B2 P3B3 P3B4 P6B2 P6B3 P9B1 P9B2 P1B2 P11B1 Total Nests (A) No. of nests with 1 egg (B) Total eggs (C) No. of nests with 1 chick (D) Total chicks (E) No. nests where 1 chick fledged (F) Total chicks fledged (G) No. of nests with 1 egg No. of nests with 2 eggs Laying success (B/A) Clutch size (C/B) Nesting success (D/B) Hatching success (E/C) Chick success (G/E) Egg success (G/C) Fledging success (F/D) Reproductive success (F/B) Overall productivity (F/A) a Statistics were calculated using ratio estimator spreadsheets and may differ slightly from the values reported in Table

26 Adults Nests Mean no. of adults Mean no. of nests Figure 6. Mean number of black-legged kittiwake adults (counted throughout the census window) and the number of black-legged kittiwake nests counted on 4 July (± 7 days). 24

27 Table 14. Black-legged kittiwake population counts at Chowiet Island, Alaska. ab Replicate Mean n SD First Count 1 Jun 6 Jun 18 Jun 6 Jun 6 Jun 22 Jun 22 Jun 1 Jul 19 Jul 12 Jun 1 Jun 21 Jun 2 Jun 17 Jun Last Count 29 Jul 28 Jun 6 Aug 25 Jul 25 Jul 18 Jul 16 Jul 21 Jul 23 Jul19 Jul 4 July 25 Jul 22 Jul 3 Aug a Data were not collected in 1976, , 1992, , and 23. b (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 25

28 Table 15. Black-legged kittiwake nest counts at Chowiet Island, Alaska. ab Replicate Mean n SD Jul nest count (± 7 days) First Count 12 Jun 1 Jun 21 Jun 2 Jun 17 Jun Last Count 19 Jul 4 Jul 25 Jul 23 Jul 3 Aug a Data were not collected in , , 1992, 1992, , and 23. b (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 26

29 Table 16. Black-legged kittiwake population counts at Chowiet Island, Alaska, in 27. Dates Statistics Plot 17 Jun 19 Jun 24 Jun 3 Jun 4 Jul 1 Jul 23 Jul 27 Jul 28 Jul 3 Aug Mean SD Max A2B A2B A3B A3B A3B A6B A6B A9B A9B Totals Table 17. Black-legged kittiwake nest counts at Chowiet Island, Alaska, in 27. Dates Statistics Plot 17 Jun 19 Jun 24 Jun 3 Jun 4 Jul 1 Jul 23 Jul 27 Jul 28 Jul 3 Aug Mean SD Max A2B A2B A3B A3B A3B3 1 1 A6B A6B A9B A9B Totals

30 Table 18. Breeding chronology of thick-billed murres at Chowiet Island, Alaska. cd Mean Median Mean Median No. of nests First Last First Last Year hatch SD n a hatch jump SD n jump monitored b hatch hatch jump jump Jul 11 Aug Jul 11 Aug Jul 11 Aug Jul 9 Aug Jul Aug Jul 1 Aug 6 Aug 2 Aug Jul Aug Jul 8 Aug 4 Aug 22 Aug Jul Aug Jul Jul 9 Aug Aug 8 Jul 2 Aug 1 Aug 23 Aug Jul Jul 9 Aug Aug 8 Jul 13 Aug 27 Jul Jul Jul 8 Aug Aug 8 Jul 11 Aug 28 Jul 21 Aug Jul Jul 18 Aug Aug 12 Jul 3 Jul 11 Aug 27 Aug Jul Jul Jul 16 Aug 2 Aug > 2 Sep a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in , 1992, 1994, , and 23. d (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 28

31 Table 19. Frequency distribution of hatch dates for thick-billed murres at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ab Date n = a Data were not collected in , 1992, 1994, , and 23. b () = data collected/potentially collected but not compiled as of print date. 29

32 1% 9% 8% Percent of nest sites 7% 6% 5% 4% 3% Egg loss Chick loss Productivity 2% 1% % Figure 7. Re productive performance of thick-billed murres at Chowiet Island. Egg loss= (A-B)/A; Chick loss= (B-C)/A; Productivity= C/A, where A= number of nest sites with an egg, B= number of nest sites with a chick, and C= number of sites with a fledged chick. 3

33 Table 2. Reproductive performance of thick-billed murres at Chowiet Island, Alaska. ab No. of sites No. of sites No. sites w/ Hatching success Fledging success Reproductive success Year w/ egg (A) w/ chick (B) fledged chick (C) (B/A) (C/B) (C/A) a Data were not collected in , 1992, 1994, , and 23. b () = data collected/potentially collected but not compiled as of print date. 31

34 Table 21. Reproductive performance of thick-billed murres at Chowiet Island, Alaska, in 27. Plots Statistics a 3M1 3M4 3M6 3MJH2 3M1 Total n mean SD Parameter 3M3 3M5 3M7 3MJH 3MJH3 3MJH4 3M3 No. of sites with an egg (A) No. of sites with chick (B) No. of sites with chick fledged (C) Hatching success (B/A) Fledging success (C/B) Reproductive success (C/A) a Statistics were calculated using ratio estimator spreadsheet and may differ slightly from the values reported in Table 2. 32

35 Mean no. of adults Figure 8. Mean number of thick-billed murres counted on index plots at Chowiet Island, Alaska. 33

36 Table 22. Thick-billed murre population counts at Chowiet Island, Alaska. ab Replicate Mean n SD Murre species combined Mean n SD First Count 2 Jun 22 Jun 2 Jun 2 Jun 2 Jun 19 Jul 19 Jun 26 Jun 21 Jun 21 Jun 26 Jun Last Count 1 Aug 28 Jun 1 Aug 1 Aug 1 Aug 23 Jul 29 Jul 19 Jul 31 Jul 3 Jul 28 Jul a Data were not collected in 1976, , 1992, 1994, , and 23. b () = data collected/potentially collected but not compiled as of print date. 34

37 Table 23. Thick-billed murre population counts at Chowiet Island, Alaska, in 27. Dates Statistics Plot 26 Jun 2 Jul 4 Jul 9 Jul 16 Jul 21 Jul 22 Jul 23 Jul 27 Jul 28 Jul Mean SD Max A3M A3M A6M A9M Totals

38 Table 24. Breeding chronology of common murres at Chowiet Island, Alaska. cd Mean Median Mean Median No. of nests First Last First Last Year hatch SD n a hatch jump SD n jump monitored b hatch hatch jump jump Jul 12 Aug Jul 1 Aug Jul 1 Aug Jul Aug Jul 1 Aug 6 Aug 2 Aug Jul Aug Jul 22 Aug 1 Aug 22 Aug Jul Aug Jul Aug Jun 1 Aug Jul Aug Jul 1 Aug 22 2 Jul Jul 11 Aug Aug 6 Jul 11 Aug 26 Jul 29 Aug Jul Jul 9 Aug Jul 9 Aug 28 Jul Jul Jul 6 Aug Aug 29 Jun 4 Aug 23 Jul 22 Aug Jul Jul 15 Aug Aug 13 Jul 3 Aug 2 Aug 27 Aug Jul Jul Jul 3 Aug 4 Aug > 2 Sep a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in , 1992, 1994, , and 23. d (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 36

39 Table 25. Frequency distribution of hatch dates for common murres at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ab Date n = a Data were not collected in , , , , and 23. b () = data collected/potentially collected but not compiled as of print date. 37

40 1% 9% 8% 7% Percent of nest sites 6% 5% 4% 3% Egg loss Chick loss Productivity 2% 1% % F igure 9. Reproductive performance of common murres at Chowiet Island. Egg loss= (A-B)/A; Chick loss= (B-C)/A; Productivity= C/A, where A= number of nest sites with an egg, B= number o f nest sites with a chick, and C= number of sites with a fledged chick. 38

41 Table 26. Reproductive performance of common murres at Chowiet Island, Alaska. ab No. of sites No. of sites No. sites w/ Hatching success Fledging success Reproductive success Year w/ egg (A) w/ chick (B) fledged chick (C) (B/A) (C/B) (C/A) a Data were not collected in , 1992, 1994, , and 23. b () = data collected/potentially collected but not compiled as of print date. 39

42 Table 27. Reproductive performance of common murres at Chowiet Island, Alaska, in 27. Plots Statistics a 3M1 3M2 3M3 3M4 3M6 3M7 3MJH 3MJH2 3MJH4 9M1 9M3 Total n mean SD Parameter 3M5 3MJH3 No. of sites with an egg (A) No. of sites with chick (B) No. of sites with chick fledged (C) Hatching success (B/A) Fledging success (C/B) Reproductive success (C/A) a Statistics were calculated using ratio estimator spreadsheets and may differ slightly from the values reported in Table 26. 4

43 Mean no. of adults Figure 1. Mean number of common murres counted on index plots at Chowiet Island, Alaska. 41

44 Table 28. Common murre population counts at Chowiet Island, Alaska. ab Replicate Mean n SD Murre species combined Mean n SD First Count 28 Jun 19 Jul 19 Jun 26 Jun 21 Jun 21 Jun 26 Jun Last Count 21 Jul 23 Jul 29Jul 19 Jul 31 Jul 3 Jul 28 Jul a Data were not collected in , 1992, 1994, , and 23. b () = data collected/potentially collected but not compiled as of print date. 42

45 Table 29. Common murre population counts at Chowiet Island, Alaska, in 27. Dates Statistics Plot 26 Jun 2 Jul 4 Jul 9 Jul 16 Jul 21 Jul 22 Jul 23 Jul 27 Jul 28 Jul Mean SD Max A3M A3M A3M A3M A3M A6M A9M A9M A1M A1M Totals

46 Table 3. Frequency of occurrence of prey in diets of common and thick-billed murres at Chowiet Island, Alaska. Frequency is expressed as the percentage of food samples in which each species was present. ab Date begin end No. samples Cephalapods Clupeidae Clupea pallasii 2. Osmeridae Mallotus villosus Hypomesus pretiosus 2.3 Thaleichthys pacificus Salmonidae 7.8 Gadidae Hexagrammidae 3.9 Zaproridae Zaprora silenus Trichodontidae Trichodon trichodon Ammodytidae Ammodytes hexapterus Pleuronectidae 2.3 Unid. Prey item a Data were not collected in 1978, , , 23, 26 and 27. b () = data collected/potentially collected but not compiled as of print date. 44

47 Table 31. Breeding chronology of parakeet auklets at Chowiet Island, Alaska. cd Mean Median No. of nests First Last First Last Mean Year hatch SD n a hatch monitored b hatch hatch fledge fledge fledge Jul 5 25 Jun 16 Jul 22 3 Jun Jun 2 28 Jun 1 Jul Jul Jul Jun 13 Jul 2 Aug 6 Aug 5 Aug 26 2 Jul Jul Jun 7 Jul 28 Jul 15 Aug 4 Aug 27 2 Jul Jul Jun 21 Jul 2 Aug 8 Aug 6 Aug a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in and d (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 45

48 Table 32. Frequency distribution of hatch dates for parakeet auklets at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ab Date n = a Data were not collected in and b () = data collected/potentially collected but not compiled as of print date. 46

49 1% 9% 8% 7% Percent of nest sites 6% 5% 4% 3% Egg loss Chick loss Productivity 2% 1% % Figure 11. Reproductive performance of parakeet auklets at Chowiet Island, Alaska. Egg loss= (A-B)/A; Chick loss= (B-C)/A; Productivity= C/A, where A= number of nest sites with an egg, B= number of nest sites with a chick, and C= number of sites with a fledged chick. 47

50 Table 33. Reproductive performance of parakeet auklets at Chowiet Island, Alaska. ab Parameter Total eggs (A) No. eggs lost to: disappearance abandonment breakage 3 4 Total chicks (B) No. chicks lost to: disappearance death No. chicks fledged (C) Hatching success (B/A) Fledging success (C/B) Reproductive success (C/A) a Data was not collected in , , and b () = data collected/potentially collected but not compiled as of print date. 48

51 Sep 5-Sep 26-Aug 16-Aug 6-Aug 27-Jul No. of individuals 1 17-Jul 7-Jul 27-Jun 17-Jun 7-Jun 28-May 18-May 8-May Figure 12. Counts of parakeet auklets on a water plot at Chowiet Island, Alaska. 49

52 27 No. of individuals Aug 15-Aug 8-Aug 1-Aug 25-Jul 18-Jul 11-Jul 4-Jul 27-Jun 2-Jun 13-Jun 6-Jun 3-May 23-May 16-May 26 No. of individuals Aug 15-Aug 8-Aug 1-Aug 25-Jul 18-Jul 11-Jul 4-Jul 27-Jun 2-Jun 13-Jun 6-Jun 3-May 23-May 16-May 25 No. of individuals Aug 15-Aug 8-Aug 1-Aug 25-Jul 18-Jul 11-Jul 4-Jul 27-Jun 2-Jun 13-Jun 6-Jun 3-May 23-May 16-May 22 No. of individuals Aug 15-Aug 8-Aug 1-Aug 25-Jul 18-Jul 11-Jul 4-Jul 27-Jun 2-Jun 13-Jun 6-Jun 3-May 23-May 16-May 1998 No. of individuals Aug 15-Aug 8-Aug 1-Aug 25-Jul 18-Jul 11-Jul 4-Jul 27-Jun 2-Jun 13-Jun 6-Jun 3-May 23-May 16-May Figure 13a-e. Counts of parakeet auklets on a water plot at Chowiet Island, Alaska. 5

53 Table 34. Population counts of parakeet auklets at Chowiet Island, Alaska, in 27. Counts were made between 73 and 93. Dates 23 May 26 May 27 May 28 May 3 May 1 Jun 2 Jun 3 Jun 5 Jun 6 Jun 8 Jun 9 Jun 12 Jun 13 Jun 14 Jun 22 Jun No. of Individuals Table 34. Continued. Dates 3 Jun 6 Jul 11 Jul 19 Jul 31 Jul 1 Aug 17 Aug Maximum Date maximum counted No. of Individuals Jun 51

54 Table 35. Breeding chronology of rhinoceros auklets at Chowiet Island, Alaska. cd Mean Median No. of nests First Last First Last Mean Year hatch SD n a hatch monitored b hatch hatch fledge fledge fledge Jul Aug Jul Aug Jun Jun Jun 6 Jul 6 Jul Jul Jul Jun 8 Jul a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining parameters. These dates may include observations > 7 days apart. c Data were not collected in 1978, , , 23, and d (-) = data not collected in that year; () = data collected/potentially collected but not compiled as of print date. 52

55 Table 36. Frequency distribution of hatch dates for rhinoceros auklets at Chowiet Island, Alaska. Julia n No. nests hatching on Julian date ab Date n = a Data were not collected in 1978, , , 23, and b () = data collected/potentially coll ected but not compiled as of print date. 53

56 1% 9% 8% 7% Percent of nest sites 6% 5% 4% Egg loss Chick loss Productivity 3% 2% 1% % Figu re 1 4. Rep rod uc tive perf orm a nce o f rh inoceros auklets at Chowiet Island, Alaska. Egg loss= (A-B )/A ; Ch ick loss= (B-C)/A; Productivity= C/A, where A= number of nest sites with an egg, B= num b er of n est site s w it h a ch ick, and C = nu mber of sites with a fledged chick. 54

57 Table 37. Reproductive performance of rhinoceros auklets at Chowiet Island, Alaska. ab Parameter Total eggs (A) No. eggs lost to: disappearance abandonment breakage Total Chicks (B) No. chicks lost to: disappearance death No. chicks fledged (C) Hatching success (B/A) Fledging success (C/B) Reproductive success (C/A).51 a Data were not collected in 1978, , , 23, and b () = data collected/potentially collected but not compiled as of print date

58 Table 38. Census of rhinoceros auklet burrows at Chowiet Island, Alaska. a Colony Spruce Cove Sub-colony A Sub-colony B Sub-colony C Total Landing Cove South Bay Sub-colony Sub-colony Sub-colony Sub-colony Sub-colony Total South East Colony 18 Island-wide total 566 > > a Data were not collected in 1978, , , , and 24. b () = data collected/potentially collected but not compiled as of print date. 56

59 Table 39. Relative biomass of prey in diets of rhinoceros au klets at Chowiet Island, Alaska. Numbers represent the percentage of the mass of combined food samples comprised by each spec ies. ab Date begin 1 Jul 7 Jul 15 Jul end 26 Jul 13 Jul 2 Jul No. sa mples No. individual prey items Total mass (g) Osm eridae Mallotus villosus Hypomesus pretiosus Salmonida e Oncorhynch us ket a Gadidae Theragra chalcogr amma Gadus macrocephalu s Scorpaenidae Sebastes spp Anoplopomatidae Anoploma fimbria Hexagrammidae Hexagrammos decag rammus Ophiodon elongates Ammodytidae Ammodytes hexapteru s Pleuronec tidae Uni d. larval fish a Data were not collected in 1978, , , 23, and 26. b () = data collected/potentially collected but not compiled as of print date. 57

60 Table 4. Frequency of occurre nce of prey in diets of rhinoceros au klets at Chowiet Island, Alaska. Frequency is expressed as the percentage of food samples in which each species was ab present Date begin 1 Jul 7 Jul 15 Jul end 26 Jul 13 Jul 2 Jul No. samples Osmeridae Mallotus villosus Hypome sus pretiosus Salmon idae Oncorhynchus keta Gadidae Theragra chalcogramma Gadus macrocephalus Scorpaenidae Sebastes spp Anoplopomatidae Anoploma fimbria Hexagrammidae Hexagrammos decagrammus Ophiodon elongates Ammodytidae Ammodytes hex apterus Pleuronectidae Unid. larval fish a D ata w ere not collected in 1978, , , 23, and 26. b ( ) = d ata colle cted/pote n tiall y coll ecte d but not com p iled as of pri nt d ate. 58

61 Table 41. Species composition of prey in diets of rhinoceros auklets at Chowiet Island, Alaska. Values are expressed as the percentage of total individual prey items comprised by each s pecies. ab Date begin 1 Jul 7 Jul 15 Jul end 26 Jul 13 Jul 2 Jul No. samples Osmeridae Mallotus villosus Hypomesus pretios us Salmonidae Oncorhynchus keta Gadidae Theragra chalcogramma Gadus macrocep halus Scorpaenidae Sebastes spp Anoplopomatid ae Anoploma fimbria Hexagrammidae Hexagrammos decagrammus Ophiodon elongates Ammodytidae Ammodytes hexapterus Pleuronectidae Unid. larval fish a Data were not collected in 1978, , , 23, and 26. b () = data collected/potentially collected but not compiled as of print date. 59

62 Table 42. Breeding chronology of horned puffins at Chowiet Island, Alaska. cd Mean Median No. of nests First Last Year hatch SD n a hatch monito red b hatch h a tch First fledge Last fledge Jul Jul 17 Aug > 4 Sep Jul Jul Jul 3- Aug Jul Jul Jul 14 Aug > 2 Aug Jul Jul Jul 16 Aug 26 Aug 27 8 Aug Aug Jul 15 Aug > 2 Sep a Sample size used for the calculation of mean and median hatch dates. These dates are a sub-sample for which we have observations of egg to chick in 7 days. b Total used for estimating the remaining paramete rs. T hese dates may in clude observations > 7 days apart. c Data were not collected in d (-) = data not collected in that year; () = data collected /potentially collected but not compiled as of print date. 6

63 Table 43. Frequency distribution of hatch dates for horned puffins at Chowiet Island, Alaska. Julian No. nests hatching on Julian date ab Date n = a Data were not collected in b () = data collected/potentially collected but not compiled as of print date. 61

64 1% 9% 8% 7% Percent of nest sites 6% 5% 4% Egg loss Chick loss Productivity 3% 2% 1% % Figu re 1 5. Rep rodu ctive p erfo r man c e of horned puffins at Chowiet Island, Alaska. Egg loss= (A- B)/A ; C hick loss= (B-C)/A; Prod uctiv i ty= C /A, where A= number of nest sites with an egg, B= num b er of n est site s with a chi c k, an d C= number of sites with a fledged chick. 62

65 Table 44. Reproductive performance of horned puffins at Chowiet Island, Alaska. ab Parameter Total eggs (A) No. eggs lost to: disappearance abandonment breakage Total chicks (B) No. chicks lost to: disappearance death No. chicks fledged (C=C 1 +C 2 ) chicks fledged (C 1 ) chicks still present (C 2 ) Hatching success (B/A) Fledging success (C/B) Reproductive success (C/A).4.8 a Data were not collected in and b () = data collected/potentially collected but not c ompiled as of print date

66 Sep 5-Sep 26-Aug 16-Aug 6-Aug 27-Jul 17-Jul No. of individuals 1 7-Jul 27-Jun 17-Jun 7-Jun 28-May 18-May 8-May Figure 16. Population counts of horned puffin s at Cho wiet Island, Alaska. 64

67 65 2 -J 7 ul May 2 3- n 2 -J Jul 1-Aug 8-Aug 5-Aug 2-Aug 9-Aug 3-May May 6-Jun 13-Ju -Jun 27 un 4-Jul -Jul May 2 3- n 2 ul 11-3-May May 6-Jun 13-Ju -Jun 27-Jun 4-J Jul 18-Jul 25-Jul 1-Aug 8-Aug 15-Aug 22-Aug 29-Aug Ju May 23 - n 2 -J 1 1-Aug 8-Aug 15-Aug -May 3 May 6-Jun 13-Ju -Jun 27 un 4-Jul l 8-Jul 25-Jul 22-Aug 29-Aug n 2 -J 1 1-Aug 8-Aug 15-Aug 22-Aug 29-Aug Figure 17a-1 horned p May -May 7d. Count May 6-Jun s of 13-Ju -Jun uffins at Ch 27 un 4-Jul owiet Island, Alaska. 11-Jul 8-Jul 25-Jul