Mammals of Fish Springs National Wildlife Refuge, Utah: assessing diversity, and effects of long-term wetland management on native and introduced species

Abstract

Fish Springs National Wildlife Refuge, one of the most isolated wildlife refuges in the lower 48 US states, was established with the singular purpose of transforming a natural desert wetland into managed habitat for migratory waterfowl.  The longitudinal effects of wildlife management on non-target species are rarely examined.  In this study, we used specimen-based evidence from historical and modern surveys to 1) compile a list of the mammal fauna of Fish Springs NWR, 2) identify other regional species from within the eastern Great Basin that may occur on the refuge but have yet to be detected, and 3) assess how 60 years of intensive waterfowl management may have affected mammal diversity and abundance.  Results document 33 species of mammals currently (or formerly) present at Fish Springs.  It is likely that several additional species, primarily small mammals (shrews, bats, and rodents), are present on the refuge.  One species thought to have been introduced during the 20th century, was in fact present prehistorically, and one non-native species that was introduced appears to have suffered a recent population crash.  Changes in species’ abundance were evident as a result of habitat modifications and management practices, but otherwise, there is no evidence of major impact on native mammals.