There appears to be a marked scarcity of Blue Tits this autumn and early winter. i have looked at two sites we work regularly.
At our woodland feeding station, of Teddy Heights near Arnside we have caught only 63 so far compared to 164 in the same period last year. Of these 46% are adults compared to 17% last year.
At Leighton Moss in the reed beds and willow scrub this years total to date is 323 compared with 594 last year. Adult percentage has gone from just 4.7 in 2010 to 25% this year.
These low numbers and high percentage of adult birds suggest that survival of young birds has been poor. Almost all our nest box sites had good productivity up to the fledging stage so any high mortality must have been after fledging.
Talking to other ringers from Nottingham, South Lancs, and Yorkshire at the BTO conference last weekend I got a similar story of low Numbers and high adult percentages. Also talking to other members of the Group and local garden bird feeders they are experiencing similar low numbers.
John
1 comment:
Similar experience from some opportunistic holiday ringing at a garden feeder in Borrowdale this summer - Blue Tit 49 juvs out of 113; Great Tit 23 juvs our of 63.
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