The autumn Manx Shearwater work resulted in slightly fewer chicks being ringed than in 2010, but many more adults. These differences are unlikely to reflect population changes or breeding success directly, because the coverage was a week earlier than in previous years. This meant that more adults were still feeding their chicks, more pre-breeding adults were looking for possible mates and breeding sites, and fewer chicks were old enough to be emerging from burrows. The numbers caught each night suggested that the peak emergence of chicks came at the end of the study period in 2011. Considering only the dates when there were catches in both years, there was a very impressive 29% increase in the number of chicks found in 2011, compared with 2010.
The earlier timing of the shearwater work also resulted in the first confirmation that Lundy-bred birds are returning to the island: two birds ringed as chicks in 2008 were recaptured. At three years old they were likely to be prospecting pre-breeders, but it will not be long before Lundy chicks are returning to breed in sufficient numbers to cause further acceleration in population growth; immigration from other colonies was probably the only relevant factor in the years immediately after rat eradication. A third, older shearwater was found dead in the breeding colony on Skokholm, Pembrokeshire. It had been ringed on Lundy in 1992 and retrapped on Lundy in 1996. Given that they do not usually swap colonies once they become established breeders, the most likely explanation seems to be that it was ringed as a prospecting pre-breeder and tried breeding on Lundy for a few years, before moving to an established colony because of Lundy's rat problem.
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