Ecological Models of Amphibian Abundance in Palouse Prairie Wetlands

burrowing owl

[Photo: Graduate student, Erim Gomez, releasing captured amphibians from live traps.]

Scientific Poster Abstract: Joint Meeting of the Society for Northwestern Vertebrate Biology and the Washington Chapter of The Wildlife Society (22-25 March 2011)


We used data mining techniques to develop ecological models predicting the occurrence of over 4000 amphibians of 7 species captured during 2009 in 63 wetlands along a geographic gradient extending from the eastern Palouse Prairie bioregion to the arid Moses Lake region in central Washington. Virtually all wetlands we studied in Palouse Prairie were artificially constructed as reservoirs, conservation habitats in agricultural lands, or were associated other development projects (e.g., mitigation for road construction, golf courses, urban settings, ditches, fish ponds). We used a variety of parameters to explore the relationships of amphibian abundance with landscape context, land use, and trap and wetland habitats (e.g., emergent vegetation). Our ecological models reveal that generally only a few environmental variables are needed to effectively predict (R2 ranging from 0.35 – 0.80) occurrence of different amphibian species, including: a) presence or absence of introduced fish, b) wetland permanence and landscape context (e.g., surrounding grasslands or urban areas), and c) broad biogeographic factors (e.g., sandy soils for toads). In addition, all species demonstrated at least one or more positive ecological associations with the abundant amphibian generalists, Long-toed salamanders (Ambystoma macrodactylum) and Pacific tree frogs (Pseudacris regilla), while the American bullfrog (Lithobates catesbeianus) had a positive and the Northern leopard (L. pipiens) a negative association with introduced fish. We present summary ecological models that illustrate the biogeographic, habitat, landscape context, and community relationships of seven amphibian species in Palouse Prairie wetlands.


E. Gomez, Washington State University, WA
R.D. Sayler, Washington State University, Pullman, WA