Anthropogenic water sources such as tanks and ponds for livestock and troughs for wildlife (guzzlers) have become ubiquitous features of arid landscapes. Many species of wildlife are attracted to guzzlers, but behavior at guzzlers and effects of guzzlers upon wildlife are often poorly understood. I recorded rates of drinking and visitation by American badgers (Taxidea taxus) at guzzlers in the northern Chihuahuan Desert by use of automatic cameras over a 2-year period. Badgers visited guzzlers throughout the year, and visited primarily at night. Badgers averaged 1.87 visits per site-week and drank during only 58% of visits. The rate of visitation and the number of drinking episodes per guzzler per week increased in summer, which, in addition to having higher temperatures, is also mating season for badgers.

Large-scale restoration is occurring in many areas of the western United States and the use of genetically appropriate native plant seed is expected to increase the success of restoration efforts. Thus, determining intraspecific variation among populations and its driving forces are the first steps in successful seed sourcing. Here, we examine intraspecific variation of characters expressed in early life history stages of Cleome lutea var. lutea, an annual forb native to the western United States that has attracted increasing attention as a restoration species because it provisions diverse pollinators. We conducted a common garden experiment comprised of 9 populations sourced from across the Intermountain West in a climate-controlled growth chamber. We measured 10 life history and morphological traits and found significant among-population differences for 9 of them, including seed germination requirements and flowering status. With the exception of seed germination, this variation was not effectively captured by broad ecoregion delineations, nor was it significantly explained by source site climatic differences or geographic distance between sites. However, flowering status was significantly explained by latitude of the source population (P = 0.033), suggesting that among-population variation reflects divergent adaptation to photoperiod. The variation in life history traits that differentiates our study populations indicates that informed seed sourcing will be necessary when using C. lutea var. lutea for restoration. More comprehensive spatial sampling that stratifies both environmental and geographic variates is needed to determine the drivers of population differentiation and the scale of local adaptation in this species. Such sampling can be used to better inform appropriate seed sourcing decisions. Until then, a cautious approach to sourcing this species for use in restoration is indicated.

North American waterfowl winter throughout a large geographic area, and the choice of wintering site has a direct impact on survival and fitness. Climatic and food variables are the most commonly cited factors influencing abundance and distribution of wintering migratory birds, including waterfowl. We conducted stratified aerial surveys at a northern latitude wintering site, Great Salt Lake (GSL), Utah, to describe the importance of this wintering area and to examine the influence of weather and food on the abundance of total ducks, Northern Shovelers (Anas clypeata), and goldeneye species (Bucephala spp.). Surveys indicated that up to 270,000 ducks use the GSL during winter, making it an important wintering area in the Pacific Flyway. Peak abundance of total ducks was positively correlated with overwinter temperatures. Northern Shoveler abundance was positively correlated with elevation of the GSL; higher lake elevation indicated more open water and hence more overwintering habitat. Goldeneye abundance was correlated with the continental population of the species and food abundance. All models had moderate fit (r² > 0.40). The GSL is unique in the United States as it is a large body of water where consistent ice cover does not occur and foraging habitat is available to ducks throughout winter. Our results suggest that ambient temperature and habitat availability are primary factors in the abundance of total wintering waterfowl, though food abundance seemed to influence wintering population size of individual duck species. We hypothesize that ducks endure the cold, hypersaline conditions on the GSL to exploit the abundant food supply and remain close to primary breeding regions.

Before white-nose syndrome arrives in Nebraska, it is important to document the preexposure distributions of cave bats in the state. We examined the distributions of Myotis lucifugus (little brown myotis), Myotis septentrionalis (northern long-eared myotis), and Perimyotis subflavus (tri-colored bat) in eastern Nebraska by setting acoustic detectors for a single night at 105 sites in wooded habitats during summers of 2012 and 2014. We compared 2 methods of determining presence at each site. Results of our analyses are fine-scale distributional maps for these bats and some range extensions from published records. Results for M. septentrionalis and P. subflavus are largely consistent with previous reports. Results for M. lucifugus vary depending on the method of determining presence; however, our preferred method creates a pattern consistent with the known vouchered distribution of this species. The differences between published distributions of these species and distributions based on acoustic detection from our study might result from a lack of extensive netting in many areas of eastern Nebraska, underrepresentation of P. subflavus from mist net surveys in Nebraska, and a recent westward range expansion of P. subflavus and M. septentrionalis in southern Nebraska.

Seed dispersal dynamics strongly affect plant community assembly in restored annual grass—infested ecosystems. Modifying perennial grass seeding rates and frequency may increase perennial grass establishment, yet these impacts have not yet been quantified. To assess these effects, we established a field experiment consisting of 288 plots (1 m²) in an eastern Oregon annual grass—dominated shrubsteppe ecosystem. In this study, the amount, timing, and frequency of perennial grass seeding events, soil moisture availability, and annual grass seed bank density were manipulated. We found that more frequent perennial grass seeding events combined with high perennial grass seeding rates produced the highest perennial grass density and biomass 2 years following seeding. However, we also found that if annual grass seed density was 1500 seeds · m^-2 or higher, perennial grass density and biomass decreased, regardless of seeding strategy. Because of this finding, it appears that a threshold is crossed between 150 and 1500 annual grass seeds · m^-2. Adding water in the first growing season initially facilitated perennial grass establishment but only produced higher perennial grass density following the second growing season when annual grass density was lowest. Assessing the existing annual grass seed bank prior to seeding can likely forecast restoration outcomes because high annual grass seed densities likely interfere with and reduce perennial grass recruitment. In addition, if annual grass seeding density is 1500 seeds · m^-2 or lower, modifying the temporal patterns of perennial grass seed arrival will increase the likelihood that a perennial grass seed finds a safe-site.

Little is known about the role of microbial biofilms in nutrient cycling and ecosystem processes within desert springs. However, biofilms produce microscale physicochemical variation important to ecosystem function. We used microelectrodes to measure microscale physicochemical (temperature, pH, O₂, and H₂S) heterogeneity in biofilms at Devils Hole, Nevada. Additionally, we measured water column and pore water nutrient concentrations in 2 autotrophic (Spirogyra, cyanobacteria) and 1 heterotrophic (Beggiatoa) biofilm types. Spirogyra and cyanobacteria followed similar physicochemical trends; however, Spirogyra had more pronounced diurnal and seasonal variation. Oxygen concentrations within the biofilms varied with sample month, light availability, and biofilm type. We also assessed the nutrient limitation of desert spring microbial biofilms using a nutrient-diffusing substrata experiment. Autotrophic and heterotrophic biofilms responded differently to nutrient treatments. The differences between cyanobacteria and Spirogyra have implications on the ecosystem function of desert springs, as well as other ecosystems with diverse biofilm communities, and suggest that a change in microbial biofilms could alter ecosystem biogeochemical dynamics.

We describe a new springsnail species, Pyrgulopsis hualapaiensis, from the Lower Colorado River basin (northwestern Arizona) that has an ovate- to narrow-conic shell and narrow penis ornamented with a small gland on the distal edge of the lobe. This new species differs from closely similar congeners from the Lower Colorado River basin in several details of female reproductive anatomy and in its mtCOI haplotype (3.0%–5.0% mean sequence divergence). Bayesian, maximum parsimony, and distance-based phylogenetic analyses of COI data congruently resolved P. hualapaiensis as sister to a divergent lineage of Pyrgulopsis thompsoni in the middle Gila River watershed (southeastern Arizona), although this relationship was not well supported. Pyrgulopsis hualapaiensis is endemic to a spring complex in the Hualapai Indian Reservation that is a culturally sensitive site for the tribe. The small population of these snails appears to be robust despite recent habitat modifications (trenching of outflow and construction of a spring box) and disturbance from road traffic. Future conservation measures could include monitoring of the population and augmentation of the gravel habitat used by these snails.

Harvester ants are influential in many ecosystems because they distribute and consume seeds, remove vegetation, and redistribute soil particles and nutrients. Understanding the interaction between harvester ants and plant communities is important for management and restoration efforts, particularly in systems altered by fire and invasive species such as the sagebrush-steppe. Our objective was to evaluate how vegetation cover changed as a function of distance from Owyhee harvester ant (Pogonomyrmex salinus) nests within a sagebrush-steppe ecosystem. We sampled 105 harvester ant nests within southern Idaho, USA, that occurred in different habitats: annual grassland, perennial grassland, and native shrubland. The influence of Owyhee harvester ants on vegetation was larger at the edge of ant nests, but the relationship was inconsistent among plant species. Percent cover was positively associated with distance from harvester ant nests for plant species that were considered undesirable food sources and were densely distributed. However, percent cover was negatively associated with distance-from-nests for patchily distributed and desirable plant species. For some plant species, there was no change in cover associated with distance-from-nests. Total vegetation cover was associated with distance-from-nests in the shrubland habitat but not in the 2 grasslands. The dominant plant species in the shrubland habitat was a densely distributed shrub (winterfat, Krascheninnikovia lanata) that was defoliated by harvester ants. Our results suggest that Owyhee harvester ants increase spatial heterogeneity in plant communities through plant clearing, but the direction and magnitude of effect will likely be contingent on the dominant vegetation groups. This information may inform future management and plant restoration efforts in sagebrush-steppe by directly considering the islands of influence associated with harvester ant engineering.

In 1988, a study of federally endangered San Joaquin kit foxes (Vulpes macrotis mutica) was initiated to develop techniques for translocating kit foxes onto Naval Petroleum Reserve No. 1 (NPR-1) in California. Our objective is to review the translocation program and provide recommendations for future efforts. There were no problems trapping, translocating, and maintaining foxes in captivity. We released 12 foxes onto NPR-1 in 1989 and 28 foxes in 1990. Of the 12 foxes released in 1989, 10 died within 1 year. Of 28 foxes released in 1990, 1 was still alive, 24 were dead, and the fate of 3 was undetermined when the study was terminated on 30 April 1992. Annual survivorship of translocated foxes was 0.03, which was less than survivorship of free-ranging foxes (0.35). Survivorship was not influenced by year of release, sex or age of translocated animals, or terrain in which foxes were released. Predation was the main cause of death. Six foxes survived through 1 breeding season, and 3 of these 6 foxes survived through 2 breeding seasons. Four of the 6 foxes bred with free-ranging foxes. Excluding 1 fox that moved 124 km before being killed by a vehicle, the distance between the release site and the location of death averaged 9.9 km (SE 1.9) for 11 foxes released in 1989 and 4.4 km (SE 1.1) for 24 adults released in 1990. The distance between the release site and the location of death was less for foxes released from pens in hilly terrain (3.1 km, SE 1.7) than for foxes released in level terrain (5.6 km, SE 1.5). Declining prey availability may have negatively influenced survivorship. Survivorship also may have been low because foxes were not familiar with their environment, including food and cover locations. Installing artificial dens or other forms of escape cover may improve survival of translocated foxes. If mortality factors can be mitigated, we believe the likelihood that foxes can be successfully translocated is good. To increase survivorship and to reduce the length of time between the release date and pair-formation we recommend that foxes be released in fall.

Pronghorn (Antilocapra americana) exhibit complex spatial and temporal variation in seasonal movements and range use across their distribution. However, knowledge of seasonal movements, routes, and distribution of pronghorn within the sagebrush-steppe of the northern Great Basin is lacking. From October 2011 to October 2013, I monitored movements of adult female pronghorn across an area of over 1.5 million hectares along the northwestern Nevada and southeastern Oregon border using GPS/VHF-equipped collars. I used 68,834 GPS locations from 32 female pronghorn to determine migration timing, seasonal distributions, individual fidelity to winter and summer ranges, and population-level routes used during the migration period. Collared pronghorn were conditionally migratory, with 65% migrating an average of 30.0 km the first year and 100% migrating an average of 39.1 km the second; one individual migrated over 160 km between summer and winter ranges. Seasonal ranges averaged 143.3 km² during the summer, and from 252.9 to 459.9 km² during the winter (2010/2011 and 2011/2012, respectively). Individual pronghorn demonstrated wide variation in directional movement between summer and winter ranges, and there was high overlap of common areas across seasons and time periods. Pronghorn showed stronger fidelity to summer ranges than to winter ranges, and occupied higher elevations during the summer months, descending to lower elevations during the winter. Deeper snow and colder temperatures in 2012/2013 compared to 2011/2012 corresponded to longer average migration distances, fewer exploratory movements, larger winter ranges, lower elevational use, and a shift in winter range location. Habitat conversion, degradation, and fragmentation have accumulated across the sagebrush-steppe biome and are negatively affecting the long-term persistence of dependent wildlife. Applying knowledge of important seasonal use areas and routes used during migration in future conservation planning can mitigate impacts to pronghorn habitat and provide for long-term conservation.

Desert mistletoe, Phoradendron californicum (Viscaceae), is a dioecious parasitic plant that grows on woody legumes in the Mojave and Sonoran Deserts, produces minute flowers during winter, and is dispersed by birds defecating fruits. Pollination of desert mistletoe has not been examined despite the species' reliance on insects for transporting pollen from male to female plants. I investigated the pollination of P. californicum parasitizing Acacia greggii (Fabaceae) shrubs at 3 sites at different elevations in the Mojave Desert of southern Nevada during February 2015. I examined pollen from male flowers, aspirated insects landing on female flowers, and counted pollen grains in insect pollen loads. Desert mistletoe's tricolpate pollen differed from a previous description by being oblate instead of subprolate in equatorial view. Female flowers were visited by 13 species of Diptera in 10 genera and 6 families and 3 species of Hymenoptera in 3 families. Almost all (98.5%) of the pollen carried by insects was from desert mistletoe. Five species of phytophagous fruit flies in Tephritidae were frequently found on flowers, comprising 53% of the insects collected, but carried low amounts of P. californicum pollen. Two species of blow flies in Calliphoridae, both larval decomposers of animals, were also relatively abundant on flowers and carried moderate to high pollen loads. Flies in Syrphidae, 2 predators and 1 plant-decomposer, carried varying amounts of conspecific pollen. Conspecific pollen loads also varied on a species of native bee in Halictidae and on naturalized honey bees in Apidae. Desert mistletoe appears to be pollinated mostly by tephritids, due to their abundance on female flowers, and by calliphorids. Blow flies would be more likely than fruit flies to carry pollen between male and female plants on different host shrubs due to their larger size and stronger flight. Parasitic, dioecious P. californicum plants appear to rely on a web of mutualism between fruit-eating birds and flower-fertilizing insects.

Communal brooding, which can occur as a result of brood amalgamation or communal parental care, is a common alternative brooding strategy observed in many precocial bird species. Although the occurrence of long-term communal brooding has been documented in numerous waterfowl species, and to a lesser extent in gallinaceous species, the occurrence and mechanisms facilitating temporary or short-term communal broods is less understood. During the 2013 and 2014 breeding seasons, we anecdotally observed temporary communal brooding in 3 Northern Bobwhite (Colinus virginianus) broods and one Scaled Quail (Callipepla squamata) brood. We present 3 mechanisms that may explain the occurrences of temporary communal brooding: (1) cool weather conditions observed at intermittent intervals throughout the breeding season, (2) predator avoidance behavior, and (3) a random proximity mechanism that triggers communal brooding in these highly gregarious bird species. It is our hope that these observations will facilitate future research investigating the impact that temporary communal brooding may have on survival and recruitment of gallinaceous birds.

In June 2008, I discovered a single jumping mouse (Zapus) cranium in a Barn Owl (Tyto alba) pellet from below an active nest along Cerrososo Creek, Colfax County, northeastern New Mexico. Although the cranium could not be identified to species, this specimen could potentially represent a previously unknown population of the endangered New Mexico meadow jumping mouse (Z. hudsonius luteus). In 2009 and 2010, I collected pellets at 8 Barn Owl nesting or roosting sites along streams in my study area with the following objectives: (1) determine whether Barn Owl pellets could be used to gain information about the abundance and distribution of this Zapus population, (2) use pellets to acquire additional Zapus specimens to aid in positive identification of the jumping mouse species present, and (3) potentially document a previously unknown population of the endangered New Mexico meadow jumping mouse. Focusing only on pellets produced during the Zapus active (nonhibernation) summer period, I dissected 298 pellets containing 487 individual mammalian prey items from 12 genera but did not locate any additional Zapus remains. Examination of owl pellets appears to be a poor survey tool for Zapus, perhaps due to the jumping mouse's short summer active period, natural low population density, and preference for tall, dense riparian vegetation.

The Columbian Sharp-tailed Grouse (Tympanuchus phasianellus columbianus; hereafter CSTG) occupies approximately 10% of its historic range and is a species of conservation concern in 7 U.S. states and British Columbia. Because little is known about the status of CSTG in Wyoming, we sought to model the relative probability of lek site occurrence within the known distribution of CSTG in the state to identify areas that contained previously undocumented lek sites. The proximity of nesting and brood-rearing habitats to leks advocates their use as a focus of conservation for prairie grouse, including CSTG. We modeled a resource selection function (RSF) to identify areas that were predicted to have a high probability of lek occurrence. In areas identified by the RSF, we searched for leks by conducting ground surveys and surveys from a fixed-wing airplane using aerial infrared (AIR) technology. We identified 6 previously undocumented CSTG leks through ground searches and 4 previously undocumented Greater Sage-Grouse (Centrocercus urophasianus) leks through AIR searches. Newly identified leks represented a 22% increase in the number of known CSTG leks in south central Wyoming. Our method not only improved knowledge of CSTG status in Wyoming, but may also improve identification of unknown lek sites and conservation of lekking habitat and additional reproductive habitats for prairie grouse species in other western states and provinces.