Houston Toad (Bufo (Anaxyrus) houstonensis) Tadpoles Decrease Their Activity in Response to Chemical Cues Produced from the Predation of Conspecifics and Congeneric (Bufo (Incilius) nebulifer) Tadpoles

摘要

Anurans have been shown to reduce their activity in the presence of predation-related chemical cues. We exposed tadpoles of the federally endangered Houston Toad, Bufo (Anaxyrus) houstonensis, to three chemical cues: A no-predation cue produced by the presence of only predatory anisopteran nymphs (Anax junius), a conspecific-predation cue produced from the consumption of conspecific tadpoles by A. junius nymphs, and a heterospecific-predation cue produced from the consumption of coastal plain toad (Bufo (Incilius) nebulifer) tadpoles by A. junius nymphs. We measured tadpole activity levels before and after exposure to the cues. Tadpole activity was not influenced by the no-predation cue, but it decreased significantly during exposure to either predation cue. The reduction in activity did not differ significantly between predation cue treatments. These data suggest that: 1) B. houstonensis tadpoles will respond to predation, but not the presence of a predator alone. 2) There may be a chemical homology between the predation cues. 3) When developing with B. nebulifer tadpoles, B. houstonensis may experience negative long-term life historical effects.