Comparing disturbance and generalism in birds and mammals: A hump-shaped pattern

Using indices as proxies, we observed that comparing a large number of common birds and mammals, the level of generalism peaks in species inhabiting habitats at intermediate disturbance levels. This pattern might be universal, at least in these homeothermic vertebrates. Birds show nonetheless some differences in pattern from mammals, where specialization at intermediate levels of disturbance is not present. Differences in ecological and evolutionary traits between birds and mammals might determine different adaptive responses to historical anthropogenic changes, explaining these taxa-specific hump-shaped patterns.