Adult survival rates of Shag Phalacrocorax aristotelis, Common Guillemot Uria aalge, Razorbill Alca torda, Puffin Fratercula arctica and Kittiwake Rissa tridactyla on the Isle of May 1986-96
Harris, M.P.; Wanless, S.; Rothery, P. (2000). Adult survival rates of Shag Phalacrocorax aristotelis, Common Guillemot Uria aalge, Razorbill Alca torda, Puffin Fratercula arctica and Kittiwake Rissa tridactyla on the Isle of May 1986-96. Atlant. Seabirds 2(3-4): 133-150 In: Atlantic Seabirds. Seabird Group and Dutch Seabird Group: Sandy, Bedfordshire. ISSN 1388-2511, more | |
Authors | | Top | - Harris, M.P.
- Wanless, S., more
- Rothery, P.
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Abstract | On the Isle of May (UK) between 1986 and 1996, the average adult survival of Shags Phalacrocorax aristotelis was 82.1%, Common Guillemots Uria aalge 95.2%, Razorbills Alca torda 90.5%, Puffins Fratercula arctica 91.6% and Kittiwakes Rissa tridactyla 88.2%. Shags, Razorbills and Puffins all had a single year of exceptionally low survival but these years did not coincide. In contrast, Kittiwake survival declined significantly over the period and there was evidence that substantial non-breeding occurred in several years. Breeding success of Kittiwakes also declined, which gives rise to concern for its future status. Given a high enough level of resighting, return rates (the proportion of birds known to be alive one year that were seen the next year) on a year-by-year basis provide a reasonable indication of relative changes in adult survival. |
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