Role of Substrate Cues in Habitat Selection by Recently Metamorphosed Bufo Terrestris and Scaphiopus Holbrookii

Abstract

Amphibians exhibit high rates of evaporative water loss that can affect their distribution, movements, and patterns of habitat use. Forest clearcutting alters habitat and results in environmental changes such as canopy removal and leaf litter loss that may promote drier microclimates in harvested clearcuts. Subsequently, clearcutting has been shown to generally reduce amphibian abundances and richness. We investigated the role of substrate cues in habitat differentiation between clearcuts and forests in juvenile Southern Toads (Bufo terrestris) and Eastern Spadefoot Toads (Scaphiopus holbrookii) in laboratory experiments. Neither B. terrestris nor S. holbrookii exhibited a preference for a single substrate when offered the choice between forest soil and clearcut soil. However, S. holbrookii significantly preferred forest substrate over clearcut substrate when forest litter was added to the forest soil. The affinity for forest litter exhibited by juvenile S. holbrookii suggests that the availability of suitable microhabitats may be an important determinant of S. holbrookii distributions and may explain previously reported habitat associations in field studies.