The influence of temperature and body size on duration of immobility in salamanders of the genus Desmognathus

Abstract

AbstractFive of seven species (83.8% of the individuals) of the plethodontid salamander genus Desmognathus became immobile during field observations. Average immobility durations varied from 32-60 s for times < 180s (N= 281), with an additional 132 becoming immobile for longer than 180s. Air temperature was the only variable positively correlated with immobility duration, but it explained only a minute amount of observed variation. Only D. wrighti, the most terrestrial species, differed from other species in immobility duration. The postures of five species of immobile dusky salamanders were observed in the field. Salamanders generally assumed body positions classified as straight as opposed to coiled or contorted. There were no significant differences among species in posture frequency, nor were there significant differences in salamander length or immobility duration among posture categories. There are no specific immobility postures in Desmognathus that serve solely antipredator functions. Like woodland salamanders (Plethodon spp.), Desmognathus individuals remain immobile in the position in which they are encountered.