Gulliver travels to the fragmented tropics: geographic variation in mechanisms of avian extinction

Irrespective of geography, forest destruction and fragmentation lead to lower avian species richness. The underlying mechanisms causing local extirpations have been studied most thoroughly in northern temperate landscapes, where higher levels of brood parasitism, nest predation, and possibly decreased food availability are responsible for the loss of some species. Tropical landscapes are being similarly altered, but studies of responses by tropical birds remain relatively scarce. Predicting how tropical birds respond to habitat loss and fragmentation should not be extended directly from the results of temperate investigations. Tropical birds possess different evolutionary and life histories, which make them vulnerable to a different suite of threats than those normally considered for birds from temperate regions. These same traits, including greater physiological and sensory specialization, reduced dispersal capabilities, and much lower local and regional population densities, indicate that strategies for conserving bird diversity will be different in tropical landscapes than those for temperate regions.