Why do juvenile Chinese pit-vipers (Gloydius shedaoensis) select arboreal ambush sites?

Abstract

Ontogenetic shifts in habitat use are widespread, especially in ectothermic taxa in which juveniles may be an order of magnitude smaller than large adult conspecifics. The factors that generate such habitat shifts are generally obscure, but we studied an unusual system that allowed us to compare consequences of habitat selection between adults and juveniles. Pit-vipers (Gloydius shedaoensis) on a small island in north-eastern China feed almost entirely on seasonally migrating birds. During the spring bird-migration period, individual snakes consistently re-used either arboreal or terrestrial ambush sites. Snakes in trees were smaller (and more philopatric) than snakes on the ground. This ont..