A sexually dimorphic plumage character in the Coal TitParus aterwith notes on the Marsh TitParus palustris

Abstract

Gosler, A. G. & King, J. R. 1989. Asexually dimorphic plumage character in the Coal Tit Parus ater with notes on the Marsh Tit Parus palustris. Ring. & Migr. 10: 53–57. Although Coal Tits may be sexed during the breeding season on the presence or absence of a brood patch or cloacal protruberance, no plumage differences have been noted previously, so that sexing has not been possible outside this period. We present observations of Coal Tits trapped at two sites in southern England which indicate that the bib of this species is strongly dimorphic in shape, extent and colour intensity.