AMNWR 2010/04 BIOLOGICAL MONITORING AT AIKTAK ISLAND, ALASKA IN 2009 Slade F. Sapora, Allyson L. Larned, and Brie A. Drummond Key words: Aiktak Island, Alaska, Aleutian Islands, ancient murrelet, Cepphus columba, common murre, double-crested cormorant, fork-tailed storm-petrel, Fratercula cirrhata, Fratercula corniculata, glaucous-winged gull, horned puffin, Larus glaucescens, Leach’s storm-petrel, Oceanodroma furcata, Oceanodroma leucorhoa, pelagic cormorant, Phalacrocorax auritus, Phalacrocorax pelagicus, Phalacrocorax urile, pigeon guillemot, population trends, productivity, red-faced cormorant, Synthliboramphus antiquus, thick-billed murre, tufted puffin, Uria aalge, Uria lomvia. U.S. Fish and Wildlife Service Alaska Maritime National Wildlife Refuge 95 Sterling Highway, Suite 1 Homer, AK 99603 April 2010 Cite as: Sapora, S.F., A.L. Larned, and Brie A. Drummond. 2010. Biological monitoring at Aiktak Island, Alaska in 2009. U.S. Fish and Wildl. Serv. Rep., AMNWR 2010/04. Homer, Alaska. Southern coast of Aiktak Island, Alaska, in late July. TABLE OF CONTENTS Page INTRODUCTION ........................................................................................................................................... 1 STUDY AREA ............................................................................................................................................... 1 METHODS .................................................................................................................................................... 2 INTERESTING OBSERVATIONS ................................................................................................................ 5 ACKNOWLEDGMENTS ................................................................................................................................ 5 REFERENCES .............................................................................................................................................. 5 FIGURES AND TABLES ............................................................................................................................... 9 Fork-tailed storm-petrel ........................................................................................................................ 10 Breeding chronology ...................................................................................................................... 10 Reproductive performance ............................................................................................................. 13 Chick growth .................................................................................................................................. 17 Food habits .................................................................................................................................... 18 Leach’s storm-petrel ............................................................................................................................. 21 Breeding chronology ...................................................................................................................... 21 Reproductive performance ............................................................................................................. 24 Chick growth .................................................................................................................................. 28 Food habits .................................................................................................................................... 29 All storm-petrels .................................................................................................................................... 32 Reproductive performance ............................................................................................................. 32 Populations .................................................................................................................................... 36 Morphology .................................................................................................................................... 39 Band resightings ............................................................................................................................ 40 All cormorants ....................................................................................................................................... 41 Reproductive performance ............................................................................................................. 41 Populations .................................................................................................................................... 45 Black oystercatcher .............................................................................................................................. 46 Breeding chronology ...................................................................................................................... 46 Reproductive performance ............................................................................................................. 49 Populations .................................................................................................................................... 51 Glaucous-winged gull ........................................................................................................................... 53 Breeding chronology ...................................................................................................................... 53 Reproductive performance ............................................................................................................. 56 Populations .................................................................................................................................... 59 Food habits .................................................................................................................................... 65 Common murre ..................................................................................................................................... 72 Breeding chronology ...................................................................................................................... 72 Reproductive performance ............................................................................................................. 75 Thick-billed murre ................................................................................................................................. 77 Breeding chronology ...................................................................................................................... 77 Reproductive performance ............................................................................................................. 80 All murres .............................................................................................................................................. 82 Populations .................................................................................................................................... 82 Pigeon guillemot ................................................................................................................................... 86 Populations .................................................................................................................................... 86 i TABLE OF CONTENTS (continued) Page Ancient murrelet.................................................................................................................................... 90 Breeding chronology ...................................................................................................................... 90 Reproductive performance ............................................................................................................. 93 Horned puffin ........................................................................................................................................ 95 Breeding chronology ...................................................................................................................... 95 Reproductive performance ............................................................................................................. 98 Chick growth ................................................................................................................................ 100 Populations .................................................................................................................................. 101 Tufted puffin ........................................................................................................................................ 106 Breeding chronology .................................................................................................................... 106 Reproductive performance ........................................................................................................... 109 Chick growth ................................................................................................................................ 111 Populations .................................................................................................................................. 112 Food habits .................................................................................................................................