Asynchronous hatching and food limitation: a test of Lack's hypothesis

摘要: -Lack's (1954, 1968) hypothesis that asynchronous hatching of altricial birds is an adaptive response to unpredictable food shortages during the breeding season was examined in highly granivorous Zebra Finch (Poephila guttata). I compared growth and survival nestlings artificially created synchronous broods reared under food-limited food-abundant conditions aviary. also role parental experience on nestlings. There no differential mortality due either asynchrony or abundance. Young abundant treatments grew more rapidly, however, than those food-restricted treatments. Heaviest a brood quickly their lightest siblings when limited, supporting Lack's hypothesis. Further, light heavy occurred abundant, suggesting can be maladaptive some ecological conditions. Nestlings by inexperienced parents suffered greater slower raised experienced parents. Prefledging mass correlated with size at adulthood. Received 25 November 1987, accepted 17 September 1987. LACK proposed potential shortages. According this hypothesis, disparity young completion results hierarchy among siblings, youngest sibling receives less food. Brood reduction starvation chick may occur times scarcity, result higher probability for remainder if all were fed equally (Ricklefs 1965). Few studies have tested experimentally while documenting manipulating abundance (e.g. Slagsvold 1982,1985; Bengtsson Ryden 1983; Fujioka 1985; Mock Ploger 1987). In study effect nestling Finches guttata) captivity limitation simulated synchrony eggs before incubation thus able compare "synchronous" "asynchronous" broods. three predictions derived from scarce, facilitates Present address: Institute Environmental Studies, University Washington, Seattle, Washington 98195 USA. young, providing benefits older siblings. First, late-hatched are likely die grow slowly last-hatched Second, heaviest faster limiting. Furthermore, one would expect not disadvantageous abundant. Third, there differences rank estimated how influences relationship between rates, prefledging mass,