Surface wear of incoloy and darvic bands on Atlantic Puffin adults and chicks |
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Authors: | André R Breton Antony W Diamond Stephen W Kress |
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Institution: | Atlantic Cooperative Wildlife Ecology Research Network (ACWERN) and Department of Biology, University of New Brunswick, Bag Service 45111, Fredericton, NB, E3B 6E1 Canada;Seabird Restoration Program, National Audubon Society, 159 Sapsucker Woods Road, Ithaca, NY, 14850 USA |
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Abstract: | ABSTRACT. Bands are a common marking method in bird studies and capture-mark-reencounter (CMR) models are often used to analyze banding data. Common to this family of models are two assumptions: marks do not fall off or become unreadable and individuals within groups remain equally detectable. When data fail to meet these assumptions, results of CMR analyses may be biased. In studies of long-lived seabirds exposed to coarse nesting substrates, band wear is especially problematic. We compared surface wear from abrasion against rocks on incoloy and darvic bands applied to a long-lived seabird, the Atlantic Puffin ( Fratercula arctica ). In 2003 and 2004, surface wear on bands applied to chicks and adults was scored at five colonies in the Gulf of Maine. We used logistic regression to analyze two subsets of these data by fitting the probability of being worn (one or more characters difficult to read or obliterated) to band age, bird age, and band type. In both analyses, an evidence ratio provided exclusive support for the model that included all factors. Immature puffins largely avoid colonies and remain at sea until their second or third summer after hatching. Consequently, probabilities of being worn were delayed on both band types by 4 yr on bands applied to chicks compared to adults. Based on our estimates, 25% and 87% of darvic bands applied to chicks and adults, respectively, were worn after 5 yr. Wear was reduced by 71% and 87% annually on incoloy compared to darvic bands applied to adults and chicks, respectively. To uphold assumptions of CMR models, we recommend incoloy bands over darvic in studies spanning more than about 5 yr of long-lived seabirds exposed to coarse substrates. |
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Keywords: | Atlantic Puffin Bay of Fundy capture mark recapture CMR Fratercula arctica seabird |
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