Mojave Desert Tortoise Studies, Documentation, Permitting, and Mitigation Programs at Project Sites

Mojave Desert Tortoise Studies, Documentation, Permitting, and Mitigation Programs at Project Sites image
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Biological consultants protect Mojave Desert tortoises from potentially harmful projects by determining their presence on project sites, assessing project effects, and sometimes translocating tortoises from project development areas. FirstCarbon Solutions (FCS) biologists can conduct technical studies and documentation, acquire project permits, and implement minimization and monitoring measures for any project involving Mojave Desert tortoises.

Preparing for a development project in the deserts of southern California means more than blueprints and funding – it also can entail safely translocating protected Mojave Desert tortoises to off-site locations. Biologists are often tasked with site assessments, surveys, mitigation programs, and monitoring for desert tortoises to ensure the project moves forward while maintaining environmental responsibility and compliance with laws that protect this species and its habitats.

Scientists at consulting firms like FCS use a stepwise approach to ensure that project effects on desert tortoises and their habitats are avoided or minimized. When a project is implemented in the range of the Mojave Desert tortoise, biologists conduct a series of technical studies, documentation, and obtain permits to satisfy requirements specified in U.S. Fish and Wildlife Service (USFWS) protocols for determining project effects on the species. Technical studies include habitat assessments and protocol presence-absence surveys. If the species is detected on a project site, biologists will consult with the USFWS and California Department of Fish and Wildlife (CDFW) to acquire permits to allow the project to go forward in a manner that minimizes harm to tortoises and their habitats.

The Mojave Desert Tortoise 

Mojave Desert tortoises are medium-sized turtles in the tortoise family (Testudinidae), a family of turtles that lead a completely terrestrial existence. Mojave Desert tortoises are one of six related species of tortoises that occur in North America, primarily in the southern United States and northern Mexico. Desert tortoises and their close relatives are known for their burrowing specialization, and they can excavate deep burrows that allow them to escape extreme temperatures and predators. Mojave Desert tortoises are most active in the spring when their favorite food plants, annual wildflowers, are abundant following winter rains.

Desert tortoises and their relatives are long-lived species and individuals may live for 100 years or more, and long-term persistence of their populations relies on adult tortoises achieving these long lives and reproducing over their lifetimes. Though desert tortoises and their ancestors have thrived for more than 35 million years, in recent times they have become imperiled species due to the actions of humans. Threats to their existence include human developments, mining, livestock grazing, off-road vehicle recreation, and other human activities that cause habitat loss and degradation. Other threats include droughts, wildfires, climate change, and hyper-predation by subsidized predators such as common ravens and coyotes. Mojave Desert tortoises are listed as Threatened under the federal Endangered Species Act (ESA) and were recently uplisted from Threatened to Endangered under the California Endangered Species Act (CESA). Under both laws, “take” of desert tortoises is prohibited without a permit.

Habitat Assessments

The first step to determining project effects on Mojave Desert tortoises is conducting a habitat assessment. The habitat assessment begins with a desktop analysis that plots the project location within the distributional range of the tortoise, a species that occurs in the Mojave and Colorado Deserts of California, Nevada, Arizona, and Utah. If the project is located within the known range of the desert tortoise, biologists will visit the project site to characterize the habitat on-site. A basic rule of thumb is to look for desert scrub habitats dominated by creosote shrubs and soils that are friable or easily excavated. However, tortoises may occur in areas that do not contain creosote shrubs or in areas where burrows would be difficult to excavate. In these cases, biologists will look for other desert scrub communities or cover sites such as caliche caves to determine whether the site could support presence of the species. If biologists determine that the site supports habitats that would allow for occurrence by desert tortoises, the next step is to conduct a protocol presence-absence survey for the species.

Presence-Absence Surveys

After biologists determine that a project will be implemented in the range of the Mojave Desert tortoise and they’ve detected habitat for the species during an initial site visit, the next step is to conduct a presence-absence survey. Per protocol defined by the USFWS, presence-absence surveys are to be implemented when tortoises are most active, including during the spring (April and May) or early fall (September and October).

Presence-absence surveys are implemented by biologists who have experience searching for desert tortoises. Despite their decent size, slow movements, and occurrence in areas of sparse vegetation, desert tortoises are remarkably cryptic and can remain undetected by the untrained eye. Biologists will search for tortoises on a project site by walking parallel transects across the site spaced in a manner that allows for 100% visual coverage of the ground surface. During the survey, the biologists will search for tortoises and sign indicating presence of tortoises, such as tracks, scats (feces), burrows, and carcasses. Any tortoise sign found by biologists will be assessed for recency, such as the timing a scat was deposited by a tortoise or recency of occupancy of a burrow by a tortoise. The biologists will map the locations of tortoises, burrows, and other signs detected during the survey using Global Positioning System (GPS) technology. These data help the biologists to characterize the tortoise population on-site, including an estimation of numbers and densities of tortoises on the project site.

Recently, biologists have developed techniques to search for tortoises on project sites using unmanned aerial vehicles (UAV) fitted with cameras and GPS technology. UAV technology is a fast-growing method in wildlife studies because of its efficiency and cost effectiveness compared to traditional ground-based surveys. While UAV technology is extremely useful and expedient in searching for tortoises and burrows, researchers are quick to point out that it does not replace pedestrian surveys. Instead, the technology works best when used in tandem with on-the-ground research, as human eyes can find evidence of burrows and tortoises that the drones miss – and vice versa.

Once the project site has been surveyed by the biologists and supplemented with UAV survey data, the next step is assessing potential project impacts to desert tortoises and their habitats.

Determination of Project Effects

Following the presence-absence survey, the biologists will compile their data into a report with exhibits showing the locations supporting desert tortoise habitat and desert tortoises on-site. The biologists will overlay the project development plans to determine the amount of desert tortoise habitat (e.g., vegetation, burrows) that will be affected by the project, as well as the number of tortoises that occupy the planned development area. This information will provide the basis for assessing project effects on the local desert tortoise population and tortoise habitat, and perhaps a chance for the project proponent to redesign the project to avoid impacts to desert tortoises.

Once the biologists have assessed the effects of the project on desert tortoises and detailed the effects in a technical report, the wildlife agencies will review the documentation and provide comment to the lead agency that is responsible for approving the project. In circumstances where a project would affect desert tortoises or their habitat, a take permit would be required to implement the project. This is particularly the case for projects that cannot be redesigned to avoid impacts to desert tortoises. In these cases, the tortoises would be translocated off-site to allow for project implementation. Translocation of tortoises from a project site would be considered a form of take, triggering the need for the project proponent to acquire take permits.

Take Permitting

If the biologists determine that the project would have a negative effect on tortoises and habitats on a project site and the wildlife agencies concur, the project applicant would need to acquire take permissions from the wildlife agencies to implement the project. In California, take permits would be required under the ESA and CESA. Take permitting under ESA is typically achieved in one of two ways: either through a Section 7 consultation or through a Section 10 Habitat Conservation Plan (HCP). A Section 7 consultation may be accomplished when there is a federal nexus as part of approval process for the project, such as if the project is implemented on federal lands or if a federal agency otherwise has jurisdiction on a project site. Section 7 of the ESA allows for consultation between the federal agency with jurisdiction and the USFWS to acquire take permissions. During the Section 7 consultation process, biologists with a federal agency or hired by the project proponent will prepare a Biological Assessment to assess project effects on desert tortoises. The USFWS will respond with a Biological Opinion that provides take permissions with specific conditions that must be implemented on the project to avoid or minimize adverse effects to desert tortoises.

If there is no federal agency nexus on a project, the project proponent may acquire a take permit through the Section 10 process. During this process, the biological consultant will prepare a Biological Assessment and a proposed HCP that outlines proposed measures for avoiding, minimizing, and offsetting project effects. After processing the application and approving the HCP, the USFWS issues an incidental take permit to allow the project to proceed.

As part of the federal take permitting process, whether through Section 7 or Section 10 of the ESA, the USFWS may require that a Translocation Plan be prepared and approved, particularly if desert tortoises occur in the project development area that would be moved out of harm’s way as part of project implementation. The Translocation Plan would provide details about an off-site recipient area selected for translocated tortoises and a procedure for conducting health assessments and collecting blood samples for disease testing, which will provide crucial information to prevent translocating potentially diseased animals to areas supporting healthy tortoises or vice versa. Lastly, the Translocation Plan will provide details about implementing the translocation and monitoring its success for several years afterward.

Translocation Plans are particularly needed for solar projects planned in desert areas, where state and federal agencies have directed planners to concentrate solar energy developments. In California, projects that would affect desert tortoises and occupied desert tortoise habitat would require that the project proponent acquire an Incidental Take Permit (ITP) from CDFW through Section 2081 of CESA. The biological consultant hired by the project proponent would prepare the ITP application, which would detail the project effects on desert tortoises and propose measures that would be implemented to avoid, minimize, or mitigate the effects of the project. If desert tortoises were moved from a project site, the ITP measures would include many of the same conditions outlined in the Translocation Plan submitted to the USFWS. If desert tortoise habitat were removed by the project, the ITP would also provide conditions for acquisition of off-site mitigation lands to offset the loss of habitat.

The Desert Tortoise Experts at FCS

FCS has a team of highly skilled, on-staff biologists who have technical expertise and extensive experience in conducting desert tortoise studies and documentation, obtaining and implementing state and federal incidental take permits for projects affecting desert tortoises, planning and implementing desert tortoise translocations, and performing long-term monitoring of translocations and other minimization and mitigation measures involving desert tortoises. FCS biologists have relationships with personnel at state and federal agencies, including CDFW and USFWS, and have excellent reputations and proven track records in implementing desert tortoise studies and mitigation programs.

FCS personnel hold the necessary wildlife agency permits to implement desert tortoise studies, including translocations, health assessments, blood and tissue collection, attaching and removing radiotelemetry devices, and other activities that require handling of desert tortoises. The desert tortoise experts at FCS offer a complete suite of desert tortoise services, from habitat assessments to presence-absence surveys to incidental take permitting to implementation and monitoring of translocations and other mitigation programs.

The FCS desert tortoise experts can assist with a wide array of projects implemented in areas supporting desert tortoises, including solar energy developments, gas and transmission lines, fiberoptic lines, transportation projects, water infrastructure projects, and projects implemented on public lands, such as National Park Service lands, Bureau of Land Management lands, and military installations. 

FirstCarbon Solutions (FCS), an ADEC Innovations company, comprises more than 100 individuals offering due diligence, technical analysis, planning, environmental compliance, permitting, and mitigation/monitoring services for both public and private projects. FCS has more than 30 years of experience navigating environmental regulatory complexities. Contact us for a free consultation.

About the author

Michael Tuma

Michael Tuma thumbnail

Michael has more than 25 years of experience in wildlife ecology and applied conservation. He is an expert in Endangered Species Act and California Endangered Species Act permitting and regulatory processes. He specializes in the study of tortoises, including desert tortoises, and is an experienced leader, having mentored biologists in a diversity of settings. Michael has project experience in a variety of market sectors, including renewable energy, land management, transportation, water infrastructure, gas and mineral extraction, and land development.

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