Tropical Forest Structure and the Distribution of Gliding and Prehensile-Tailed Vertebrates

Abstract

Prehensile tails and gliding have arisen only in certain taxonomic groups which could occur only on certain continents as a result of biogeographic history, e.g., no marsupials in Africa or flying squirrels in the Neotropics. However, the simultaneous occurrence of these adaptations in a number of unrelated vertebrate families in some regions but not in others, even when the same families are present, and the parallel appearance of the same characters in ecological equivalents belonging to different orders or families (e.g., Manis and Tamandua; Potos and Arctictis; and Anomalurus, Petaurista, Schoinobates, and Cynocephalus) suggests that the biogeographic patterns of these adaptations are the result of more than chance. Empirical evidence suggests that different forest structures in different parts of the world are correlated with different modes of locomotion by arboreal vertebrates. We suggest that scarcity of lianas in tropical Asia favors the long-distance strategy of gliding; high liana frequency in tropical Africa correlates with a lack of specialized locomotory adaptations for inter-tree movement; many palms, an intermediate number of lianas, and perhaps generally more fragile branches in the Neotropics are associated with prevalence of prehensile tails.