Multiyear monitoring of survival following mitigation‐driven translocation of a long‐lived threatened reptile

• Published in: Conservation biology 2019-10, Vol.33 (5), p.1094-1105
• Main Authors: Dickson, Brett G., Scherer, Rick D., Kissel, Amanda M., Wallace, Bryan P., Langin, Kathryn M., Gray, Miranda E., Scheib, Amanda F., Weise, Bruce
• Format: Article
• Language: English
• Subjects: Alternative energy sources; Animals; California; clima; climate; Colorado; conservación; conservation; Conservation of Natural Resources; Construction sites; Control; desarrollo de energía renovable; Desert animals; desert ecosystems; Deserts; ecosistemas desérticos; Environmental management; Gopherus agassizii; habitat; Habitat loss; hábitat; Mitigation; Monitoring; Renewable energy; renewable energy development; Renewable resources; Reptiles; Reptiles & amphibians; Resource management; Solar energy; Southwestern United States; Species; Survival; Testudines; Threatened species; Tortoises; Translocation; Turtles; Wildlife conservation; 保护; 可再生能源发展; 气候; 生境; 荒漠生态系统
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/cobi.13301

Translocation is used by managers to mitigate the negative impacts of development on species. Moving individuals to a new location is challenging, and many translocation attempts have failed. Robust, posttranslocation monitoring is therefore important for evaluating effects of translocation on target species. We evaluated the efficacy of a translocation designed to mitigate the effects of a utility‐scale solar energy project on the U.S. federally listed Mojave desert tortoise (Gopherus agassizii). The species is a long‐lived reptile threatened by a variety of factors, including habitat loss due to renewable energy development in the Mojave Desert and portions of the Colorado Desert in southern California (southwestern United States). We translocated 58 individual tortoises away from the project's construction site and intensively monitored them over 5 years (2012–2017). We monitored these individuals and tortoises located in the translocation release area (resident tortoises; n = 112) and control tortoises (n = 149) in a nearby location. We used our tortoise encounter data and known‐fate survival models to estimate annual and cumulative survival. Translocated tortoises in each of 2 size classes (120–160 mm, >160 mm) did not survive at lower rates than resident and control tortoises over the study period. For models with different sets of biotic and abiotic covariates, annual and cumulative estimates of survival were always >0.87 and >0.56, respectively. Larger tortoises tended to have higher survival, but translocated tortoises were not differentially affected by the covariates used to model variation in survival. Based on these findings, our translocation design and study protocols could inform other translocation projects for desert species. Our case study highlights the benefits of combining rigorous scientific monitoring with well‐designed, mitigation‐driven management actions to reduce the negative effects of development on species of conservation concern. Monitoreo Multianual de la Supervivencia de un Reptil Longevo en Peligro después de una Reubicación por Mitigación Resumen Los administradores utilizan la reubicación para mitigar los impactos negativos que el desarrollo tiene sobre las especies. El traslado de individuos hacia una nueva ubicación es todo un reto y muchos intentos de reubicación han fallado. Por esto el monitoreo robusto post‐reubicación es importante para la evaluación de los efectos de la reubicación sobre las especies. Evaluamos