Yesterday we caught some Oystercatchers at Heysham helipad. As the Oystercatchers roosting there have not been caught on a regular basis until relatively recently only about 6% were already ringed. Of these some were very interesting:
1 ringed August 1982 in Lincolnshire
1 ringed August 1993 in Lincolnshire
1 ringed in Iceland (it was also colour ringed)
1 ringed on the Isle of Mull in 1984 and caught last year.
19 were ringed in December 2008 at Heysham
10 were ringed in February 2006 at Heysham
1 from 2001 at Heysham
Perhaps of more interest than the retraps was the age structure of the birds. 97% were full adults and all but one of the remainder were at least 2 years old. This is probably down to the hard weather over the 6 weeks causing immature birds either to die or to be in such poor condition they need to feed in fields over the high tide period.
The 15 dead birds I picked up on Foulney a couple of weeks ago in the cold were all immature birds or adults that had not completed their primary feather moult. All the adults we checked at Heysham had completed their primary moult suggesting that incomplete primary moult is not a big problem in the bay however those that had failed to complete were hit particularly hard by the cold weather.