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Status of Forest Birds on Rota, Mariana Islands

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Status of Forest Birds on Rota, Mariana Islands Technical Report HCSU-048 STATUS OF FOREST BIRDS ON ROTA, MARIANA ISLANDS 1 1 1 2 3 , , , Richard J. Camp Kevin W. Brinck P. Marcos1 Gorresen Fred A. 4Amidon , Paul M. Radley , S. Paul Berkowitz , and Paul C. Banko 1 Hawai‘i Cooperative Studies Unit, University of Hawai‘i at Hilo, P. O. Box 44, Hawai‘i National Park, HI 96718 2 U.S. Fish and Wildlife Service, Pacific islands Fish and Wildlife Office, 300 Ala Moana Blvd., P.O. Box 50088, Honolulu, HI 98650 3 Division of Fish and Wildlife, Commonwealth of the Northern Mariana Islands, Department of Land and Natural Resources, P.O. Box 10007, Saipan, MP 96950 4 U.S. Geological Survey, Pacific Island Ecosystems Research Center, Kīlauea Field Station, P.O. Box 44, Hawai‘i National Park, HI 96718 Hawai‘i Cooperative Studies Unit University of Hawai‘i at Hilo 200 W. Kawili St. Hilo, HI 96720 (808) 933-0706 February 2014 This product was prepared under Cooperative Agreement CAG13AC00125 for the Pacific Island Ecosystems Research Center of the U.S. Geological Survey. Technical Report HCSU-048 STATUS OF FOREST BIRDS ON ROTA, MARIANA ISLANDS RICHARD J. CAMP1, KEVIN W. BRINCK1, P. MARCOS GORRESEN1, FRED A. AMIDON2, PAUL M. RADLEY3, S. PAUL BERKOWITZ1, AND PAUL C. BANKO4 1 Hawaiʽi Cooperative Studies Unit, University of Hawaiʽi at Hilo, P.O. Box 44, Hawai‘i National Park, HI 96718 2 U.S. Fish and Wildlife Service, Pacific Islands Fish and Wildlife Office, 300 Ala Moana Blvd., P.O. Box 50088, Honolulu, HI 98650 3 Division of Fish and Wildlife, Commonwealth of the Northern Mariana Islands, Department of Land and Natural Resources, P.O. Box 10007, Saipan, MP 96950 4 U.S. Geological Survey, Pacific Island Ecosystems Research Center, Kīlauea Field Station, P.O. Box 44, Hawaiʽi National Park, HI 96718 Hawaiʽi Cooperative Studies Unit University of Hawaiʽi at Hilo 200 W. Kawili St. Hilo, HI 96720 (808) 933-0706 February 2014 This article has been peer reviewed and approved for publication consistent with USGS Fundamental Science Practices (http://pubs.usgs.gov/circ/1367/). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ii TABLE OF CONTENTS List of Tables ....................................................................................................................... iv List of Figures ...................................................................................................................... v Abstract ............................................................................................................................... 1 Introduction ......................................................................................................................... 1 Methods .............................................................................................................................. 3 Study Area ....................................................................................................................... 3 Bird Sampling ................................................................................................................... 3 Occupancy ....................................................................................................................... 4 Habitat variables ........................................................................................................... 4 Assessing species detection and habitat associations ..................................................... 5 Abundance ....................................................................................................................... 9 Trend Assessment .......................................................................................................... 10 Results .............................................................................................................................. 11 Occupancy ..................................................................................................................... 14 Black drongo ............................................................................................................... 16 Collared kingfisher ....................................................................................................... 17 Island collared-dove .................................................................................................... 18 Mariana crow .............................................................................................................. 18 Mariana fruit-dove ....................................................................................................... 20 Micronesian myzomela ................................................................................................. 22 Micronesian starling ..................................................................................................... 24 Rota white-eye ............................................................................................................ 26 Rufous fantail .............................................................................................................. 27 White tern ................................................................................................................... 27 White-throated ground-dove ........................................................................................ 29 Yellow bittern .............................................................................................................. 31 Status and Trend ............................................................................................................ 33 Black drongo ............................................................................................................... 33 Collared kingfisher ....................................................................................................... 33 Eurasian tree sparrow .................................................................................................. 35 Island collared-dove .................................................................................................... 36 Mariana crow .............................................................................................................. 36 Mariana fruit-dove ....................................................................................................... 37 Micronesian myzomela ................................................................................................. 37 iii Micronesian starling ..................................................................................................... 39 Rota white-eye ............................................................................................................ 39 Rufous fantail .............................................................................................................. 39 White-throated ground-dove ........................................................................................ 41 White tern ................................................................................................................... 41 Yellow bittern .............................................................................................................. 42 Discussion ......................................................................................................................... 42 Occupancy ..................................................................................................................... 44 Status and Trends ........................................................................................................... 45 Incomplete Sampling Coverage ........................................................................................ 46 Monitoring Implications ................................................................................................... 47 Island Comparisons ......................................................................................................... 48 Acknowledgements ............................................................................................................ 50 Literature Cited .................................................................................................................. 50 Appendix 1: List of transects sampled by survey .................................................................. 55 Appendix 2: Site and sampling covariates ............................................................................ 57 Appendix 3: Summary of model selection for each species .................................................... 58 Appendix 4: Occupancy model coefficients by species .......................................................... 62 Appendix 5: Predicted detection probability for final models .................................................. 70 Appendix 6: Predicted occupancy probability for final models ................................................ 75 Appendix 7: Species detection function models .................................................................... 81 Appendix 8: Birds detected and indices of occurrence and abundance ................................... 88 Appendix 9: Abundance estimates for Rota bird species by stratum and year ......................... 94 LIST OF TABLES Table 1. Resident native forest birds of Rota, their distributions, and designated conservation status. ................................................................................................................................
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