Reproductive Ecology of the Island Scrub-Jay

[摘要] Abstract. We investigated the reproductive ecology of the Island Scrub-Jay (Aphelocoma insularis), which is endemic to Santa Cruz Island, California, and is a species of conservation concern. We documented daily nest survival, probability of renesting, annual fledging success, and breeding behavior, and determined how these factors varied in relation to the habitat characteristics of the jays' home ranges. Clutch sizes, feeding rates, and nest attendance were not correlated with chaparral cover or with home-range size. In contrast, nest predation, which accounted for 92% of documented nest failures, was less likely at nests that were more concealed, at nests of breeding pairs with home ranges that were smaller and had a greater proportion of taller vegetation, and at nests that were initiated earlier in the breeding season. Researchers' activity near nests increased the likelihood of predation, although the effect diminished with a nest's age. Despite relatively low nest survival, the high frequency of re...

[学科分类] 动物科学

[关键词] Aphelocoma insularis;California;habitat-specific demography;nest survival;observer effects;reproductive ecology;Santa Cruz Island