Restoration of Spring‐Run Habitat Improves Abundance and Juvenile Survival for Endangered, Highly Endemic Salamanders

ABSTRACT Numerous imperiled species are endemic to aquifers and springs. These critical sources of freshwater are ubiquitously modified by impoundments and other infrastructure to facilitate recreation and water use, posing challenges for the conservation of their native biota. The Edwards Aquifer of central Texas exemplifies these challenges, with the intersection of two metropolitan areas and an array of threatened and endangered species endemic to the region, including several spring‐dwelling salamanders in the genus Eurycea . Many opportunities exist for spring‐run restoration, yet relatively little work has been done. In this study, we discuss the results of restoring a 21 m spring run (buried for almost 100 years) to expand habitat for endangered Barton Springs salamanders ( Eurycea sosorum ), a species endemic to only two watersheds. Using data from an 8‐year capture‐recapture study, we examined changes in abundance, survivorship, and movement affiliated with the existing and newly created habitats. We documented increased carrying capacity of the site with a dramatic increase in abundance 1.5 years after the restoration of the spring run. Comparing periods before and after stream restoration, average salamander density increased from 4.8 to 10.6 ind./m 2 and average abundance ( N ) increased from 354 to 1051. Rates of survival in the new habitat were similar for adults, but higher for juveniles while movement confirmed population connectivity between habitats. Our results demonstrate the benefit and potential of habitat restoration, particularly for spring‐dependent species, where a relatively small habitat expansion has dramatically improved population demographics for an endangered salamander.