Avian survival on islands

Island species are often predictably different from their mainland
counterparts. Milder climates and reduced predation risk on islands have
been involved to explain shifts in body size and a suite of life history
traits such as clutch size and offspring growth rate. Despite the key role
of adult survival on risk taking and reproduction, the prediction that
living on islands increases adult survival has yet to be tested
systematically. I gathered data on adult annual apparent survival from
island and mainland year-round resident species of birds from around the
world. With this large dataset (708 species), I found that species of
birds living on islands showed higher apparent survival than their
mainland counterparts in the two hemispheres and at all latitudes
controlling for several known predictors of adult survival including body
size, clutch size, and breeding system. These results shed light on the
ecological factors that influence survival on islands and extend the life
history island syndrome to adult survival.