The dark kangaroo mouse (DKM) is a rare inhabitant of the Great Basin Desert and populations appear to be declining throughout the range of the species. However, through limited early spring work we have expanded our understanding of distribution and habitat use. Through this project we hope to enhance our knowledge of the distribution, abundance, and threats facing the DKM -- information that would be vital in support of conservation actions and a species status assessment. The dark kangaroo mouse (DKM) (Microdipodops megacephalus) is an inhabitant of sandy dune margins in the Great Basin desert. The mouse's distribution is primarily restricted to Nevada and Utah with small areas of California, Idaho, and Oregon (Hafner and Upham 2011, Hall and Kelson 1959, O'Farrell and Blaustein 1974). Within that distribution population are naturally patchy and fragmented. The DKM is generally considered rare and populations appear to be declining throughout the range of the species (Auger and Black 2006, Hafner et al. 2008, Hafner and Upham 2011). Recent genetic analysis has suggested the dark kangaroo mouse occurs in at least three discrete groups with little genetic interchange (Hafner and Upham 2011, Andersen et al. 2014). Researchers have suggested that effective population sizes in each group are low and may be threatened with extirpation (Andersen et al. 2014). Work by BYU and the UDWR over the last decades failed to locate DKM at most historical locations in Utah. In 2005-2006, live-trapping surveys for the dark kangaroo mouse in the Utah portion of the Great Basin resulted in the capture of 40 individuals with a trapping effort of 11,160 trap nights (Auger and Black 2006). Kangaroo mice were only found at 4 out of 101 sites sampled. Thirty-six individuals were found at one site in Iron County and the remainder at 3 other locations across the Great Basin Desert. Capture success was similarly low in a 2014 - 2015 extensive cooperative effort between Dugway Proving Ground, UDWR, and BYU (Phillips 2018). Research has shown that as cheatgrass increases, small mammal diversity decreases with the DKM among the first species disappearing (Ostoja and Schupp 2009, Haug 2010, Freeman et al. 2014). Because of that, we have great concern for this species and the Great Basin small mammal community in general. However, lack of knowledge hampers our ability to take conservation action. Current needs are to identify as many extant populations as possible and prioritize protection of those areas against invasion by cheatgrass and/or other identified threats. Given the apparently declining population and the identification of discrete populations, the DKM could become the target of an ESA listing petition. We also lack the information to design and implement conservation measures to protect the species where they occur. In somewhat of a contrast to those dire findings, we have had more success in recent years. In the larger university-led projects, trapping efforts occurred from May through August to conform to graduate student schedules. Yet some research suggests that although DKM can be captured throughout summer, early spring trapping may result in greater success. In spring, fewer seeds are available and animals may be more enticed to enter a trap. With limited effort, 2 DKM were captured by UDWR in April in 2017 and 21 DKM in March through June 2019. Those captures included new localities located between the known existing populations. Hill Air Force Base biologist have also captured DKM in recent years and expanded the known northern extent of the species' distribution. Through that work, we now have a better understanding of the habitats DKM select and a species distribution model is being produced to help guide efforts. We propose to expand trapping during spring 2022 with hopes of enhancing our knowledge of the distribution, abundance, and threats facing the DKM -- information that would be vital in support of a species status assessment.

The goal of this project is to enhance our knowledge of the distribution, abundance, and threats facing the DKM. Tasks will include: * Use a species distribution model and ground-truthing to select sites with habitat conditions most likely to support DKM populations. * Employ two field crews to trap for DKM and other Great Basin small mammals from March through June 2022. * Review field results, update distribution maps, and develop management recommendations for DKM populations.

Research has shown that as cheatgrass increases, small mammal diversity decreases with the DKM among the first species disappearing (Ostoja and Schupp 2009, Haug 2010, Freeman et al. 2014). Because of that, we have great concern for this species and the Great Basin small mammal community in general. However, lack of knowledge hampers our ability to take conservation action. Current needs are to identify as many extant populations as possible and prioritize protection of those areas against invasion by cheatgrass and/or other identified threats. Given the apparently declining population and the identification of discrete populations, the DKM could become the target of an ESA listing petition. We also lack the information to design and implement conservation measures to protect the species where they occur.

BLM Utah Sensitive Species (BLM 2019) Wildlife Action Plan- the DKM is a SGCN and gaining further knowledge of distribution is a priority conservation need. This project will also provide information to inform actions under BLM resource management plans and Dugway Proving Ground and Hill Air Force Base Integrated Natural Resource Management Plans.

This project will provide small mammal occupancy data of populations supporting the need for data in Environmental Assessments and impact analyses. Additionally, BLM Manual 4680 directs the BLM to "determine, to the extent practicable, the distribution, abundance, population condition, current threats, and habitat needs" for sensitive species. The status of sensitive small mammal populations, including DKM and PYRA are currently unknown in the SLFO, additionally historic sites appear to be unoccupied. Data collected in this survey effort will provide data to inform analyses, planning, and implementation in project areas where pygmy rabbits exist. Furthermore, areas may be identified in this effort that would benefit from restoration work such as juniper removal. These data are needed in order to process permit renewals, and land and realty actions quickly. Locations of small mammal populations allows biologists to microsite projects and adjust prior to NEPA initiation, thereby reducing paperwork and time required to process requests.

Not applicable

BLM Manual 4680 directs the BLM to "determine, to the extent practicable, the distribution, abundance, population condition, current threats, and habitat needs" for sensitive species. The status of sensitive small mammal populations, including DKM and PYRA are currently unknown in the SLFO, additionally historic sites appear to be unoccupied. UDWR has the authority to carry out this project. UDWR will coordinate access to military lands where applicable.

All known locations of DKM captures in Utah have been compiled and a predictive distribution model is being built based on that information. Prior to project implementation, biologist will identify potential habitat based on the model and conduct site visits. Capture efforts will beginning in March 2022. Sampling will consist of setting transects of Sherman live traps baited with a seed mixture. Traps will be checked each morning before temperatures reach 80 degrees to decrease the likelihood of mortality related to heat in the trap. Traps will be closed during the day to prevent non-target animals (primarily sciurids) from entering the trap during the heat of the day. If nighttime temperatures are expected to be colder than 5ÃÂÃ Â C, each trap will be equipped with 5 g of polyfil batting (i.e., nesting material) to decrease the likelihood of exposure by captured animals. Where a capture occurs, adaptive cluster sampling will be used to help determine the extent of occupied habitat and initial measure of abundance. At sites where captures occur we will conduct field visits with the project relevant land-management agency personnel. Those visits will be used to familiarize all with the sites, identify threats to each population, and to solicit suggestions to reduce or mitigate those threats.

Once we have a better handle on the distribution of the DKM, we intend to establish a protocol to periodically monitor populations

Dugway Proving Ground Hill Air Force Base BYU BLM Salt Lake Field Office BLM Fillmore Field Office Nevada Department of Wildlife

For each identified population, we will work with the appropriate land management agency to assess the threats present in the area. We will then work together to make recommendations to help protect those sites.

Data will be used in environmental analysis, development of conservation measures, and threat assessments.