Blue tits have Excellent Productivity

After an excellent breeding season in our nest boxes with good sized broods and very few dead youngsters we expected good numbers of tits this summer in our mist netting sites. Our predictions proved true and although I have not got full details from all Group members as yet, all report good numbers of young birds, especially Blue Tits during August. For the catch of 240 that I have the data for, the percentage of adult Blue Tits in the catch is very low at just 5% suggesting excellent productivity. This compares with 2015 when after a poor breeding season the adult percentage was 37 % suggesting very low productivity.

Great Tit suggest a similar pattern although we ring smaller numbers (74) but Adult percentage is 16% compared to 31% last year.

Willow Warblers continue to pass through in good numbers, although as would be expected in smaller numbers than mid month but Chiffchaff have increased.

John