Ecological Archives E089-154-A1

Robert G. Anthony, James A. Estes, Mark A. Ricca, A. Keith Miles, and Eric D. Forsman. 2008. Bald Eagles and sea otters in the Aleutian Archipelago: indirect effects of trophic cascades. Ecology 89:2725–2735.

Appendix A (Table A1). Annual diets (number of prey items and percentage of total) of Bald Eagles at Adak, Amchitka, Kiska, and Tanaga islands, Aleutian Archipelago, Alaska 1993–1994, 2000–2002.

Mammals:

1993

1994

2000

2001

2002

Norway rats (Rattus norvegicus)

13 (5.2)

35 (10.2)

18 (7.1)

9 (3.5)

14 (5.2)

Sea otter pups (Enhydra lutris)

32 (12.9)

58 (17.0)

8 (3.2)

7 (2.7)

3 (1.1)

Subtotal

45 (18.2)

93 (27.2)

26 (10.2)

16 (6.2)

17 (6.3)

Fish:

         

Pacific cod (Gadus macrocephalus)

21 (8.5)

44 (12.8)

23 (9.1)

16 (6.2)

28 (10.4)

Rock greenling (Hexagrammus lagocephalus)

57 (22.9)

22 (6.4)

11 (4.3)

24 (9.3)

16 (6.0)

Atka mackerel (Pleurogrammus monoptergius)

2 (0.01)

0 (0.0)

3 (1.2)

26 (10.0)

11 (4.1)

Smooth lumpsuckers (Aptocyclus ventricosus)

45 (18.2)

0 (0.0)

1 (0.4)

0 (0.0)

6 (0.7)

Sculpins (Cottus spp.)

1 (0.01)

0 (0.0)

1 (0.04)

0 (0.0)

6 (0.03)

Rockfishes (Sebastes spp.)

1 (0.01)

5 (0.02)

0 (0.0)

0 (0.0)

1 (0.01)

Other Species

11 (0.05)

8 (0.03)

5 (0.02)

3 (0.01)

3 (0.01)

Subtotal

138 (55.6)

79 (23.1)

44 (17.3)

69 (26.9)

71 (26.4)

Birds:

         

Glaucous-winged Gulls (Larus glaucescens)

14 (5.6)

28 (8.2)

43 (16.7)

31 (12.0)

35 (13.0)

Rock Ptarmigan (Lagopus mutus)

1 (0.01)

15 (4.4)

17 (6.7)

16 (6.2)

26 (9.6)

Northern Fulmar (Fulmarus glacialus)

4 (1.6)

45 (13.2)

23 (9.1)

13 (5.0)

19 (7.1)

Tufted Puffins (Lunda cirrhata)

5 (2.0)

8 (2.3)

14 (5.5)

6 (2.3)

4 (1.5)

Ancient Murrelet (Synthliboramphus antiquium)

0 (0.0)

4 (1.2)

11 (4.3)

10 (3.9)

8 (3.0)

Shearwaters (Calonectris spp.)

4 (1.6)

15 (4.4)

12 (4.7)

6 (2.3)

4 (1.5)

Auklets (Aethia or Cyclorrhynchus)

7 (2.8)

11 (3.2)

1 (0.4)

13 (5.0)

10 (3.7)

Aleutian Canada Goose (Branta Canadensis)

0 (0.0)

1 (0.3)

4 (1.6)

6 (2.3)

8 (2.9)

Storm Petrel (Hydrobatinae spp.)

3 (1.2)

1 (0.3)

0 (0.0)

4 (1.5)

2 (0.7)

Northern Pintail (Anas acuta)

0 (0.0)

2 (0.6)

1 (0.4)

0 (0.0)

6 (2.2)

Common Raven (Corvus corax)

0 (0.0)

2 (0.6)

0 (0.0)

0 (0.0)

5 (1.8)

Cormorants (Phalacrocorax spp.)

4 (1.6)

9 (2.6)

6 (2.4)

8 (3.1)

0 (0.0)

Common Eider (Somaternia mollissima)

3 (1.2)

2 (0.6)

4 (1.6)

4 (1.5)

5 (1.8)

Common Murre (Uria aalge)

3 (1.2)

5 (1.5)

5 (2.0)

7 (2.7)

3 (1.1)

Other species

17 ( 6.9)

22 (6.4)

43 (16.9)

48 (18.7)

46 (17.1)

Subtotal

65 (25.2)

170 (49.7)

184 (72.4)

172 (66.9)

181 (67.3)

Total no. prey items

248

342

254

257

269


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