Abstract
Tropical birds are purported to be longer lived than their temperate
counterparts, but it has not been shown whether avian survival rates
covary with latitude worldwide. Here, we perform a global-scale
meta-analysis of 1,007 estimates from 249 studies of avian survival and
demonstrate that a latitudinal survival gradient exists in the northern
hemisphere, is dampened or absent for southern hemisphere species, and
that differences between passerines and nonpasserines largely drive
these trends. We also show that while extrinsic factors related to
climate were poor predictors of survival compared to latitude alone, the
relationship between survival and latitude is strongly mediated by
intrinsic traits ― larger species with smaller clutch size had the
highest survival. Taken together, our results suggest that interactions
between intrinsic traits and lineage-specific effects surpass latitude
and its underlying climatic factors in explaining global patterns of
avian survival.