Similar regional‑scale survival of tropical and southern temperate birds from the New World

Abstract

The general assumption that the survival patterns of tropical and southern temperate birds are similar lacks empirical data from higher latitudes. Regional comparisons of New World species are rare, and this assumption has been based on data from African studies. Here, we estimate the survival rates of 88 tropical and southern temperate bird populations (69 spe cies) from eight localities in South America to evaluate the hypothesis that the survival of these populations is homogeneous at the regional scale. We estimated survival based on the Cormack-Jolly-Seber model and compared values from diferent environments. The survival estimates ranged from 0.30 to 0.80 (0.56±0.12). Apparent survival did not difer signifcantly between low-latitude tropical environments (03°S) and the other sites from high-latitudes (between 22° and 34°S). Despite a predicted positive trend, body size was not signifcantly related to survival among passerines. On the other hand, phyloge netic relationships explained more than a third of the variation in bird survival. Based on the largest available database on South American bird species, our fndings support the hypothesis that bird survival is homogeneous, at the regional scale, along the southern hemisphere. In particular, we reinforce the hypothesis that climatic variation has a limited infuence on bird survival in the southern hemisphere.