Recent studies have documented the effects of climate variation on the distribution and local survival of a variety of animal species. However, the effects of contemporary climate change on population density cross the entire range of a species, and hence on its potential population decline, have remained mostly unexplored.
Birds are the only group of organisms for which reliable data exist over ecologically significant stretches of time. Anders and Post quantified the relationships over four decades between climatic oscillations, local temperatures, and population biology of the yellow-billed cuckoo, a North American migrant landbird, using data from the U.S. Geological Survey's Breeding Bird Survey. The cuckoo population densities across their breeding range showed a lagged effect, declining after years when the local temperatures were high. The strength of this effect was predictive of longer-term population decline, which may be caused by a relative scarcity of invertebrate prey after warmer winters. -- AMS
J. Anim. Ecol. 75, 221 (2006).
