The first documented outbreak of the amphibian fungal pathogen, Bactrachytrium dendrobatidis (Bd), often simply referred to as "chytrid", first occurred in Australia in 1993 after a mass mortality event involving multiple anuran species. Since that initial outbreak, Bd has been detected in over 350 amphibian species worldwide and has been associated with severe population declines or extinctions. Bd infection rates vary based on species and life stages impacting the skin of adults and the mouthparts of tadpoles with some species not exhibiting clinical symptoms. The fungus spreads across the skin of the amphibian causing it to thicken and impedes the exchange of water, electrolytes and respiratory gases through the skin resulting in sloughing, lethargy, weight loss, and potentially death. Most outbreaks of Bd occur at higher elevations during the cooler months. In the United States, Bd has been detected in 46 out of 50 states with the western part of the country having the highest incidences. The Utah Division of Wildlife Resources (UDWR) has been screening for Bd since August 2001. Seven out of nine native amphibian species have tested positive for Bd between 2001 and 2025 Four species (Arizona toad, Anaxyrus microscaphus; western toad, Anaxyrus boreas; Columbia spotted frog, Rana luteiventris; northern leopard frog, Lithobates pipiens) that have tested positive are listed as Species of Greatest Conservation Need (SGCN) under the Utah Wildlife Action Plan (UWAP). The Columbia Spotted Frog/Least Chub Conservation Team and Western Toad Conservation Team have identified the need to prevent the decline of current breeding sites as well as expanding populations by increasing the number of additional breeding sites using historic breeding sites or finding sites with suitable habitat that could become new breeding sites for these species. Under the UWAP, Bd is identified as a threat to anuran populations in Utah and continued screening throughout the state is important for understanding the prevalence and spread of Bd. Translocations have been discussed as a conservation management tool in both conservation teams. Identifying source sites and recipient sites are important to meet the goals of maintaining current populations while increasing the number of sites on the landscape for SGCN amphibians. Before considering source sites, recipient sites or repatriation sites for translocation or reintroductions, we need to determine Bd status of those sites to be able to make effective management decisions for performing conservation actions that have the best chances of yielding successful results with disease management considerations. All the sites being targeted for testing under this proposal have either never been tested for Bd or they were last tested prior to 2016 meaning most sites have not been tested for over a decade. Furthermore, the sites that have been previously tested over a decade ago include very low sample sizes which are inadequate for detecting an amphibian pathogen within a population. This project ensures adequate sampling size to detect whether Bd occurs at each site and current testing advancements can provide Bd infection loads for each individual that tests positive for Bd which will be essential in understanding prevalence and infection rates within a site. The Bd data will be important when making management decisions for aiding SGCN amphibian populations in the state. Neighboring states have relied on amphibian populations that had Bd introduced that led to large mortality events, but where there were surviving individuals at those sites and showed a population rebound, they were able to combat issues with Bd infections by relying on those sites to repopulate nearby breeding sites through translocation efforts from those surviving individuals. There have been suggestions that some of our SGCN amphibian species sites in Utah may have rebounded from a Bd infection which will be important to understand in order to manage those species on the landscape with such a devasting pathogen that does not have a cure or antidote to treat. It is crucial that we test these sites for Bd prevalence and infection rates to understand how to manage them and use this information to guide decisions that could increase their populations on the landscape using effective approaches.

The goal of this project is to determine the disease status of 29 sites that have been identified as ideal candidates for translocation projects, source sites for those translocation projects or broodstock considerations, potential release sites for repatriation efforts, and hatchery areas where a secondary broodstock will be created for propagation purposes. The secondary broodstock was decided necessary to aid in western toad population declines in other parts of Utah during the Western Toad Repatriation Plan Team meetings held since 2025. Objective 1: Determine status of Bd at potential source and recipient sites for Columbia spotted frogs, northern leopard frogs, and western toads to guide translocation and repatriation decisions. Objective 2: Determine status of Bd at four DWR hatchery locations that are potential sites where a second western toad broodstock will be held for propagation efforts. Objective 3: Incorporate Bd infection loads and prevalence rates data into UNHP and other DWR databases to help make informed decisions about managing SGCN amphibian populations with a pathogen occurring on the landscape. Objective 4: Update Conservation Agreement Strategies for western toads and Columbia spotted frogs with conservation actions that include these Bd infection loads and prevalence rates.

These locations have been identified as potential source, recipient, repatriation, or propagation sites that will benefit the populations in the state by using them to increase number of individuals at recipient sites, increase the number of breeding sites for repatriation efforts, and selecting the appropriate hatchery location for a secondary western toad broodstock. Conducting Bd sampling and testing at these sites now will allow for more effective management decisions for addressing SGCN amphibian population conservation efforts in the next couple years where projects have been identified for more immediate intervention.

Chytrid is listed as a potential threat to amphibian SGCNs listed in the UWAP. Maintaining and increasing populations for amphibian SGCNs are objectives in Conservation Strategies and Conservation Teams for Columbia spotted frogs and western toads. This project will result in developing a protocol for amphibian translocations that will be important to incorporate into Conservation Strategies for amphibian SGCNs and the Western Toad Repatriation Plan.

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Chytrid monitoring will be managed by the Utah Division of Wildlife Resources. Field sample collection will be performed by trained UDWR employees.

Objective 1 -- There are 29 sites that require sample collection: 7 potential repatriation sites (one in Central Region, three in Northern Region, once in Northeastern Region, one in Southern Region, and one in Southeastern Region); 7 potential source sites (four in Central Region, one in Northern Region, and two in Southern Region); 9 potential translocations or recipient sites (two in Central Region, four in Northern Region, one in Northeastern Region, one in Southern Region, one in Southeastern Region; 2 sites within the Southern Region to understand prevalence and infection load rates in Columbia spotted frog locations in the West Desert; and 4 sites at DWR hatcheries for deciding the appropriate location to create a secondary western toad broodstock for propagation purposes. Task 1 --Collect adequate number of samples at each site to have confidence in a negative Bd test result for the entire site. This number has been determined from Skerratt et al. 2008 and Gray et al. 2017. Some sites may not have the focal SGCN present and may require the collection of swabs from non-SGCN amphibians present at the site to increase number of samples. Task 2 -- A fine rayon tipped swab will be passed over the ventral surfaces 20 to 30 times targeting the pelvis patch, toe webbing, and ventral surfaces of the thighs. Place the tip into a screw top Eppendorf tube and break the tip off into the tube and close the lid. Label the tube with the species, animal ID number, date, and site. Recent studies have shown that nitrile gloves have fungicidal properties. This protocol will include updated recommendations to include the use of non-nitrile gloves. The samples are to be stored at -20 degrees Celsius until they are shipped frozen to Pisces Molecular for PCR. Direct shipping information for Pisces molecular will be included in the collection protocol. At the end of the season, the state herpetologist will request an inventory of samples collected during the spring, summer, and early fall field seasons. Samples may be transported to the Salt Lake Office to be pooled and shipped together or sent directly to Pisces Molecular by each Regional Office after contacting the company in advance. Objective 2: Collect eDNA water samples at sites to test for Bd. Task 1 -- Sites that have none or very low number of amphibians for adequate Bd testing will consider collecting eDNA water samples. Task 2 -- Organize borrowing water pumps and associated equipment from the Rocky Mountain Research Station to collect samples at identified sites. The National Genomics Center (NGC) provide field kits with filter cups, supplies, and protocols to collect eDNA samples. The eDNA samples will have to be analyzed by NGC in order to borrow eDNA sampling equipment or field kit supplies. Objective 3: Incorporate results into 2026 conservation team management discussions and repatriation planning and update Conservation Agreement and Strategies for western toads and Columbia spotted frogs based on Bd results from this project.

Monitoring will be conducted by UDWR regional biologists and the UDWR native herpetology coordinator.

UDWR regional biologists and native herpetology coordinator, National Park Service, U.S. Forest Service, U.S. Fish and Wildlife Service, Utah State University, Utah's Hogle Zoo, Sageland Collaborative, and private landowners

Chytrid detection and population assessments will inform efforts for repatriation planning for at least three SGCN amphibians. We will also update Conservation Agreement Strategies for the western toad and Columbia spotted frog to inform conservation actions for better management with chytrid on the landscape. The results from this project will provide a better understanding of the prevalence rate and infection loads of Bd in SGCN amphibian populations within Utah that can help provide guidance on appropriate conservation strategies for preserving and increasing populations across the state through translocation and repatriation efforts. A location for the second western toad broodstock will be selected based on the results of this project and propagation efforts will proceed forward to repatriate declining breeding sites within populations that cannot use the current Paunsaugunt Plateau broodstock due to differences in genetics.

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