Arboreal Dead-Leaf-Searching Birds of the Neotropics

Abstract

At least 11 spp. of birds in northern Bolivia and souther Peru are dead-leaf-searching specialists: more than 75% of foraging observations of these species were of individuals searching for insects in dead, curled leaves suspended above ground in the vegetation. All known specialists of this kind belong to the families Furnariidae and Formicariidae. An additional 6 spp. [Eubucco versicolor, E. richardsoni, E. tucinkae, Xiphorhynchus guttatus, Cranioleuca albiceps, Thryothorus genibarbis], called regular users, exhibit dead-leaf-searching behavior in 25%-75% of the foraging records. The number of specialists and regular users decreases with rising elevation in the Andes. Specialists disappear from the gradient between 2000 and 2575 m, but regular users occur as high as 3300 m, near timberline. As many as 8 spp. of dead-leaf-searching specialists coexist in western Amazonia.