The Great Tit and Blue Tit breeding season is getting off to a slow start in the University of Birmingham's Chaddesley Woods supplementary feeding study. Simone Webber reports that following the cold winter the birds are building nests later than in the previous years of the study and only two birds are laying eggs to date. This year our new Postgraduate student Kaat Brulez will be providing the birds with a calcium supplement and monitoring the effects on eggshell structure and pigmentation in addition to the ongoing studies of the effect of supplementary feeding on energetic expenditure of breeding adults which is being undertaken by Simone. Great Tits feed their chicks almost exclusively on caterpillars and their breeding is usually timed so that their chicks are in the nest at the time of peak caterpillar abundance in the woods. Simone and Kaat will be determining when the caterpillar peak is this year. They will have the invaluable help of a team of volunteers from the Worcestershire Wildlife Trust. It will be very interesting to find out whether the birds have timed their later breeding to coincide with a later appearance of caterpillars this year. Chaddesley Woods is a National Nature Reserve managed by the Worcestershire Wildlife Trust.
(photo: the first Great Tits eggs of 2010)
