title: Climatic effects on breeding grounds are more important drivers of breeding phenology in migrant birds than carry-over effects from wintering grounds.
abstract: Long-distance migrants may be particularly vulnerable to climate change on both wintering and breeding grounds. However, the relative importance of climatic variables at different stages of the annual cycle is poorly understood, even in well-studied Palaearctic migrant species. Using a national dataset spanning 46 years, we investigate the impact of wintering ground precipitation and breeding ground temperature on breeding phenology and clutch size of 19 UK migrants. Although both spring temperature and arid zone precipitation were significantly correlated with laying date, the former accounted for 3.5 times more inter-annual variation. Neither climate variable strongly affected clutch size. Thus, although carry-over effects had some impact, they were weaker drivers of reproductive traits than conditions on the breeding grounds.
authors.affiliation: British Trust for Ornithology, The Nunnery, , Thetford, Norfolk IP24 2PU, UK.
authors.forename: Nancy
authors.initials: N
authors.lastname: Ockendon
authors.forename: Dave
authors.initials: D
authors.lastname: Leech
authors.forename: James W
authors.initials: JW
authors.lastname: Pearce-Higgins
mesh_terms: D000349:Africa; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D002980:Climate; D057231:Climate Change; D052284:Clutch Size; D016208:Databases, Factual; D015233:Models, Statistical; D011157:Population Dynamics; D012621:Seasons; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D013696:Temperature; D013997:Time Factors; D006113:United Kingdom
keywords: breeding success; carry-over effect; climate change; migrant; sub-Saharan Africa