Morphological and behavioral adaptations in Bolitoglossa colonnea (Caudata, Plethodontidae) in relation to habitat use and daily activity cycle

Bolitoglossa colonnea is a member of the Bolitoglossa striatula group (sensu Wake and Lynch 1976) that inhabits low to intermediate elevations on the Caribbean slope of Costa Rica and Panama, and the Golfo Dulce area in southwestern Costa Rica and extreme western Panama. Due to their secretive habits and the low density in which these tropical salamanders generally occur, observations are rare and their natural history remains poorly known. Here we present data from field observations and a behavioral experiment that extend our understanding of the biology of this tropical salamander. Both Dunn (1926) and Taylor (1952) reported observing specimens of B. colonnea at night crawling on fallen logs and on low vegetation near a small fast-flowing stream. Bruce (1997) invariably found these salamanders close to the forest floor, either on the upper surfaces of broad-leaved herbaceous plants, on a pinnatifid fern, or on the vertical stem of a small plant. A single individual was observed crawling on leaf litter on the forest floor. The latter author remarked upon not being able to locate any salamanders during the