Quantifying development to inform management of Mojave and Sonoran desert tortoise habitat in the American southwest

Endangered Species Research
By: , and 



Two tortoise species native to the American southwest have experienced significant habitat loss from development and are vulnerable to ongoing threats associated with continued development. Mojave desert tortoises Gopherus agassizii are listed as threatened under the US Endangered Species Act, and Sonoran desert tortoises G. morafkai are protected in Arizona (USA) and Mexico. Substantial habitat for both species occurs on multiple-use public lands, where development associated with traditional and renewable energy production, recreation, and other activities is likely to continue. Our goal was to quantify development to inform and evaluate actions implemented to protect and manage desert tortoise habitat. We quantified a landscape-level index of development across the Mojave and Sonoran desert tortoise ranges using models of potential habitat for each species (152485 total observations). We used 13 years of Mojave desert tortoise monitoring data (4732 observations) to inform the levels and spatial scales at which tortoises may be affected by development. Most (66–70%) desert tortoise habitat has some development within 1 km. Development levels on desert tortoise habitat are lower inside versus outside areas protected by actions at national, state, and local levels, suggesting that protection efforts may be having the desired effects and providing a needed baseline for future effectiveness evaluations. Of the relatively undeveloped desert tortoise habitat, 43% (74030 km2) occurs outside of existing protections. These lands are managed by multiple federal, state, and local entities and private landowners, and may provide opportunities for future land acquisition or protection, including as mitigation for energy development on public lands.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Quantifying development to inform management of Mojave and Sonoran desert tortoise habitat in the American southwest
Series title Endangered Species Research
DOI 10.3354/esr01045
Volume 42
Year Published 2020
Language English
Publisher Inter-Research Science Publisher
Contributing office(s) Fort Collins Science Center
Description 18 p.
First page 167
Last page 184
Country United States
State Arizona, California, Nevada, Utah
Other Geospatial Mojave Desert, Sonoran Desert
Google Analytic Metrics Metrics page
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