Associations of the Van Dyke's salamander (Plethodon vandykei) with geomorphic conditions in headwall seeps of the Cascade Range, Washington State.

We explored the association between Van Dyke's salamander (Plethodon vandykei) and hydrologic condition, geomorphology, and vegetation structure in headwall seeps in the Cascade Range of Washington State. We modeled occurrence of P. vandykei at three site scales: between seeps, within seeps, and between microhabitat sites. We ranked a priori models using Bayesian information criterion (BIC). Using logistic regression, with presence and absence as the response, we found best approximating models for the occurrence of P. vandykei at the three site scales is predicted by hydrological and geological habitat characteristics.