Negative Phototaxis Results from Avoidance of Light and Temperature in Stream Salamander Larvae

Abstract

Abstract Forest removal is a global threat to amphibian diversity. Declines occur within these areas, but many amphibians also avoid moving into or through disturbed areas. Understanding which cues result in avoidance may provide targets for preservation of amphibian occupancy and population connectivity. Negative phototaxis is known from many amphibians, but light can serve as a cue or as a proxy for other environmental cues like temperature. This study sought to evaluate whether larval salamander habitat selection was influenced most by light or temperature cues. Because some individuals choose to remain in deforested habitat, we also assessed whether differences in habitat selection existed between individuals from forested and deforested habitat. Using a laboratory experiment, we found that salamanders use both light and temperature cues for habitat selection. Although salamanders demonstrated larger responses to temperature, they were willing to move into warmer habitats to avoid light. Individuals f...