Isle of May seabird studies in 2001
The 2001 season for seabirds on the Isle of May was characterised by high interspecific variation, particularly in breeding success. Thus some species had their most productive season since monitoring began, while others had their least productive. Timing of breeding in auks and Northern fulmars was...
| Main Authors: | , , |
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| Format: | Report |
| Language: | unknown |
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JNCC
2002
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| Online Access: | http://nora.nerc.ac.uk/id/eprint/6598/ http://www.jncc.gov.uk/pdf/jncc328.pdf |
| Summary: | The 2001 season for seabirds on the Isle of May was characterised by high interspecific variation, particularly in breeding success. Thus some species had their most productive season since monitoring began, while others had their least productive. Timing of breeding in auks and Northern fulmars was normal, while European shags and black-legged kittiwakes laid later than in recent years. Return rates were generally close to or above the long-term average, except for common guillemots which were lower. Sandeels and clupeids were the predominant prey items, but varied in importance between species. European shags had an excellent breeding season. Although breeding started later than in 2000, overall breeding success (1.53 chicks per incubated nest) was the highest recorded since intensive monitoring began in 1986. Atlantic puffins had their most successful season for four years and breeding success (0.78 chicks per pair laying) was above the long-term average. In contrast, common guillemots had the lowest breeding success since monitoring began in 1986 (0.63 chicks per pair laying). Some chicks were neglected and fledging weights were considerably lower than the long-term average. Razorbill breeding success (0.60 chicks per pair laying) was lower than the long-term average. Black-legged kittiwakes started breeding later than in recent years. Losses were high during incubation but few failures occurred during chick-rearing. Thus overall breeding success (0.61 chicks per pair laying) remained above the long-term average, although not as high as in 2000. Northern fulmars had a very poor season, with breeding success estimated at only 0.26 chicks per incubating pair, well below the long term average. The return rate of colour-ringed European shags (89.8%) in 2001 was similar to that in 2000. Black-legged kittiwake return rate (81.2%) was the highest since 1990. The return rate of common guillemots (82.9%) was slightly below the long-term average whereas razorbill and Atlantic puffin return rates (82.9% and 90.5% ... |
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