Amphibians in general, and plethodontid salamanders in particular, are highly susceptible to cutaneous water loss. We compared behavior, habitat use, and physiology of Batrachoseps attenuatus (Eschscholtz) and Ensatina eschscholtzii (Gray) in Humboldt County, California, to identify adaptations of water economy. Both species lost more body water in a dry environment than in a wet one. In the field, sites with salamanders had higher relative humidity than sites without salamanders. In behavioral experiments, both species used water-conserving postures; they positioned themselves deep in leaf litter in dry environments while remaining on the surface of leaf litter in wet environments. The slender morphology of B. attenuatus may aid in habitat partitioning by plethodontid salamanders; in the field we found B. attenuatus closer to the surface of the leaf litter than E. eschscholtzii. The evolution of a slender body shape appears to be unconstrained by microclimates typically encountered by this species.