Breeding biology of the Woodcock Scolopax rusticola in Britain.

Abstract

A total of 449 nest record cards collected by the British Trust for Ornithology during 1945-89 was used to examine timing of nesting and brood production of the Woodcock. Daily chick mortality rates were estimated from recaptures of 26 Woodcock broods during an intensive study in 1988-92. Clutches were initiated between March and July, with a mode at the end of March. On average, egg laying commenced earlier in England (median first-egg date 8 April) than in Scotland (20 April) and there were negative relationships between first-egg dates and mean March air temperatures, both between years and regionally within years. Nest survival during egg laying and incubation was 41 +/- 1% and the mean number of clutches hatched per female alive in March was 0.89 (95% CL 0.47-1.58). Chick survival until fledging was estimated as 56 +/- 8%, resulting in a mean annual production of 1.80 +/- 0.72 fledged young per female alive at the start of the breeding season. A small second peak in the distribution of first-egg dates in mid-May indicates that in some years females may attempt to rear second broods