Dutch Birding volume 31 (2009) no 1

Aberrant Great Tits in Zuid-Holland in 2006-09

From 22 November 2008 into 2009, an aberrant Great Tit Parus major was observed at Krimpen aan den IJssel, Zuid-Holland, the Netherlands. Compared with normal birds, it was much darker overall, with a completely dark head, darker upperparts and wing (without pale wing-bar), broader dark belly-stripe and dirty greenish-yellow underparts. In consecutive winters from 2006/07 to 2008/09, a bird with similar plumage has been visiting a garden in Rotterdam-Overschie, Zuid-Holland (c 15 km from Krimpen aan den IJssel). These dark plumages are considered to be the result of melanism. Similar 'black-headed' Great Tits have also been reported in Surrey, England, since 1940.

Harvey van Diek, Prins Willem Alexanderstraat 53, 6576 BL Ooij, Nederland
(info@harveyvandiek.nl)