CR 61:109-121 (2014)  -  DOI: https://doi.org/10.3354/cr01238

ABSTRACT: Spring migration of birds in many parts of the world has advanced as the climate has become warmer. Variation in advancement among species has been proposed to correlate with geography and life history features, but individual studies have reported variable results, and general patterns have been elusive. In a quantitative review of data from 389 bird species sampled at 69 European and 23 North American localities, we evaluated associations between change in the timing of migration and life history (body size, molt, broodedness), ecology (habitat, diet, nest position), and geography. We confirmed that spring migration advanced: -0.214 d yr^-1 (95% CI: -0.266, -0.162) for first-arriving individuals and -0.104 d yr^-1 (-0.139, -0.071) for the median date of passage. The rate of change in autumn was more variable: 0.090 d yr^-1 (0.002, 0.176) delay for median passage and 0.019 d yr^-1 (-0.175, 0.204) delay for the date of last departure. The response during spring was weaker in the far north and in species that migrate long distances to the wintering area. Autumn migration became increasingly delayed in species that are large-bodied, molt before departure, and that feed on seeds, insects, or fruits. Variation among species, especially during autumn, was associated in part with constraints surrounding the timing of the postnuptial molt. The results suggest that ecological and life history features of species may influence their ability to respond to climate change.

KEY WORDS: Bird · Body size · Broodedness · Diet · Latitude · Migration · Molt · Phenology