The effect of a spring gale and a freak wave on a breeding group of Common Guillemots Uria aalge
Atlantic seabirds , Volume 1 - Issue 1 p. 43- 47
In the British Isles, Common Guillemots Uria aalge normally achieve relatively high breeding success, usually fledging c. 0.7-0.8 chicks per breeding pair (Thompson et al. 1997) Severe gales can reduce breeding success, although apparently infrequent (Thompson et al. 1998). This note describes the effect of a gale on breeding Guillemots in Shetland in May 1997. Hatching success of the first egg laid by a pair of Guillemots is commonly c. 80%. The main causes of egg loss, where known, are rolling due to an inadequate nest site and/or parents, predation, and infertility (Birkhead 1977, Harris & Wanless 1988). The probability of a replacement egg being laid declines seasonally (Wanless & Harris 1988; Hatchwell 1991), this decline being more closely associated with laying date relative to surrounding pairs rather than to absolute date (Wanless & Harris 1988). However, there is a rapid seasonal decline in the productivity of replacement eggs (Hatchwell 1991).
|545797.jpg Cover Image , 9kb|