Differences in Recruitment of Young by Immigrant and Resident Great Tits in Wytham Wood

摘要: Throughout the long term study of Great and Blue Tit populations in Wytham wood, now its 43rd year, it has been apparent that population was not isolated from surroundings. tits are known to breed hedgerows gardens near there other woodlands within 5–10 km though, being managed, they thought contain less nest sites than itself. If is optimum habitat for might be wood would entirely populated with birds originating those breeding surroundings were excess production Wytham. However, clear this case, even allowing incomplete trapping adults. In any given year about half adults have raised (Fig. 1). It will noticed figure proportion born first breeders increased noticeably after 1976, when a program replacing original wooden boxes weasel-proof concrete pattern completed. The suggestion losses weasels significantly affecting structure (Dunn McCleery Perrins 1989). Analysis life tables shows R0, which should close unity equilibrium, much 1, indicating nests producing far too few recruits account overall numbers wood. most likely explanation seems part larger exchanging individuals it. only way certain evidence migration by birds, project just beginning. However purpose paper dynamics whole population, but investigate whether immigrant differ respects