Forty years later: monitoring and status of the endangered Coachella Valley fringe-toed lizard

Abstract

The Coachella Valley fringe-toed lizard, Uma inornata, was listed as endangered under the California Endangered Species Act in 1980. By that time, the lizard’s habitat was already reduced by 90%, fragmented into isolated habitat islands on private property among hundreds of landowners. Ecosystem processes that are essential for delivering sand and maintaining the lizard’s sand dune habitat were already compromised. As challenging as it was to protect its habitat under these conditions, populations of this lizard still occur across much of the area where it was found forty years ago. Annual monitoring was designed to assess the ongoing viability of these populations by quantifying the effects of potential threats and stressors and focusing adaptive management actions where they are most needed. Here we demonstrate how hypothesis-based monitoring identified specific locations where invasive plant control and sand corridor management were needed to maintain the lizard’s populations. By monitoring lizard densities within the context of environmental variables that either drive or inhibit population growth, this monitoring approach informs if, when, and where management actions are needed.