Understanding long-term patterns of burrow occupancy for the Western Burrowing Owl (Athene cunicularia hypugaea) is necessary for the conservation of this species, especially in arid, desert ecosystems where burrow occupancy data are lacking. Monthly burrow monitoring was conducted over a 4-year period (1997–2001) in southern Nevada to determine burrow occupancy patterns of Burrowing Owls and to evaluate the effects of burrow type and desert region on burrow occupancy. Burrow occupancy occurred year-round and was most consistent in the Transition region and tended to be lowest in the Mojave Desert region. Peak burrow occupancy occurred during March through May, followed by a gradual decline in occupancy through the summer and fall until January and February, when occupancy was lowest. Occupancy was significantly higher at sites with both culvert and pipe burrows than at sites with earthen burrows in disturbed habitat or earthen burrows in natural habitat. Breeding-season occupancy was not significantly higher in wetter, cooler portions (e.g., Great Basin desert region) of the study area. Results suggest that occupancy is influenced by habitat features—such as suitable burrows in open areas with low vegetation—and climatic regime.

Hydropsyche quitchupaha, n. sp., is described and illustrated based on 3 males collected in Sevier, Emery, and Kane counties, Utah. The upturned posteromesal lobes of tergum X, subapically swollen phallobase, and dorsally depressed phallus apex separate this species from all other members of the Hydropsyche scalaris Group.

Seventy-two caddisfly species in 36 genera and 15 families were collected along the Little Colorado, Verde, Gila, and Colorado rivers in Arizona. Brachycentrids, hydropsychids, limnephilids, and uenoids made up nearly 50% of the assemblage in forested sites above 2200 m. Hydropsychids, hydroptilids, and leptocerids made up 75% of the assemblage in grassland watersheds between 2200 and 1000 m, and 80% at sites below 1000 m in desert watersheds. Species richness averaged 16 at sites above 2200 m elevation, 7 between 2200 and 1000 m, and 3 below 1000 m. H' diversity was typically >3 at sites above 2200 m and <2.5 below 2200 m. Each river had distinct faunas likely due to isolation of drainages across semiarid landscapes. Low Sørensen similarity values were measured for caddisfly assemblages in the highly regulated Colorado River and the other 3 rivers. Only 17 species were collected at 14 sites along 700 km of the Colorado River. Indicator caddisfly species are provided for altered and less disturbed drainages. We added 7 species not previously reported in Arizona for a total of 154 caddisfly species in the state. We provide a baseline of caddisfly indicators for monitoring changes in ecosystem health during the predicted long-term drought and population expansion in southwestern USA.

Despite much attention to the foraging habits and hibernation patterns of food-storing mammals, little is known about the contents of winter larders under natural conditions or how animals prepare a winter larder. Here we describe the contents of 15 yellow-pine chipmunk (Tamias amoenus) winter larders from 3 different years and describe the movement of scatter-hoarded seeds into larders. We found larders by locating 14 radio-collared chipmunks in their winter dens. One additional larder was found by tracking the movement of seeds labeled with radioactive scandium-46 from scattered caches into the larder. Chipmunks formed winter dens and rapidly provisioned winter larders in the fall, just before the onset of winter. Surface caches were dynamic, with seeds residing in 1–6 cache sites ( = 2.6, s = 1.1) before being found in the larder. Distances from scattered caches to the winter larder were 34.5 m (s = 17.1). Contents of winter larders consisted of pine and shrub seeds. In 14 of the 15 larders, pine seeds contributed most to the size and caloric content of larders. Pine seeds and other seeds found in winter larders were produced by plants 2–4 months before the onset of winter. We conclude that if yellow-pine chipmunks did not scatter-hoard seeds during summer and autumn, seeds would not have been available for use in winter larders.

We examined the relationship between insolation, climate, and hibernacula of black-tailed (Crotalus molossus), Great Basin (Crotalus lutosus), and western diamondback (Crotalus atrox) rattlesnakes at 4 sites in Arizona, Nevada, and Utah, Hibernacula were located through a combination of visual searches and radio telemetry from 1995 to 2003. We used global information systems to calculate insolation and compared hibernaculum insolation values with random points representing available insolation of the surrounding habitat. Insolation reflects soil temperatures, and we predicted that hibernacula in cool climates, at high elevations, and at high latitudes would have higher insolation relative to their surroundings, while hibernacula in warmer climates would not differ from their surroundings in insolation. Coolest temperatures, highest elevations, and highest latitudes occurred on the C. lutosus and C. molossus sites, where hibernaculum insolation was higher than surrounding insolation. Temperatures were intermediate on the high-elevation C. atrox site, where hibernaculum insolation did not differ from random-point insolation, Temperatures were highest on the low-elevation C. atrox site, where hibernaculum insolation was unexpectedly lower than random-point insolation, Our observations suggest that rattlesnakes in cool climates utilize hibernacula with insolation values higher than those of their surroundings, Rattlesnakes in warm climates utilize hibernacula with insolation values lower than or similar to those of their surroundings.

The mammal fauna of western South Dakota is imperfectly known; in particular there is a notable paucity of data from Indian reservations in the region. We collected mammals from January 2003 through May 2006 using a variety of standard methodologies, including trapping with snap-traps and Macabee traps, shooting, and salvaging road- and hunter-killed animals. Herein we provide 23 specimen-based county records representing 17 species of mammals. In addition, a photo record constitutes the first report of Dasypus novemcinctus from South Dakota and the northernmost record in the United States. The possible local extirpation of Marmota flaviventris in the southern Black Hills is discussed.

We describe species richness and habitat associations of mayflies (Ephemeroptera) collected during amphibian surveys of 355 water bodies in Glacier National Park (NP), Montana, in 2006–2008. We collected 9 taxa (in 7 genera) of mayflies that were identifiable to species. Callibaetis jerrugineus hageni was collected most frequently, followed by Siphlonurus occidentalis, S. phyllis, Ameletus celer, A. similior, Parameletus columbiae, Ephemerella dorothea infrequens, Baetis bicaudatus, and Leptophlebia cupida. Siphlonurus phyllis had not been reported in the western United States prior to our surveys, and P. columbiae is a species of concern in the region. The identifications of 4 additional taxa were uncertain due to the poor condition of specimens found at only one site (Centroptilum sp. and Paraleptophlebia sp.) or because nymphal specimens could not be confidently identified (Cinygma sp. and Cinygmula sp.). Species richness of mayflies in wetlands seems low compared to that in streams and lakes in Glacier National Park. We found the most species of mayflies in beaver ponds, where we detected some species not commonly associated with lentic water bodies. Our survey was the first extensive survey of wetland invertebrates in Glacier NP and only the second that we are aware of in western Montana.

Caching of animal remains is common among carnivorous species of all sizes, yet the effects of caching on larger prey are unstudied. We conducted a summer field experiment designed to test the effects of simulated mountain lion (Puma concolor) caching on mass loss, relative temperature, and odor dissemination of 9 prey-like carcasses. We deployed all but one of the carcasses in pairs, with one of each pair exposed and the other shaded and shallowly buried (cached). Caching substantially reduced wastage during dry and hot (drought) but not wet and cool (monsoon) periods, and it also reduced temperature and discernable odor to some degree during both seasons. These results are consistent with the hypotheses that caching serves to both reduce competition from arthropods and microbes and reduce odds of detection by larger vertebrates such as bears (Ursus spp.), wolves (Canis lupus), or other lions.

We examined abundance and flight periodicity of 3 predators of bark beetles (Coleoptera: Curculionidae, Scolytinae), Temnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae), Enoclerus sphegeus (Fabricius) (Coleoptera: Cleridae), and E. lecontei (Wolcott) (Coleoptera: Cleridae), across an elevational gradient of ponderosa pine (Pinus ponderosa Lawson) forests in north central Arizona. Predator populations were estimated at 10 sites in each of 3 elevation bands (low: 1600–1736 m; mid: 2058–2230 m; high: 2505–2651 m) for 3 years (2004–2006) using pheromone-baited funnel traps targeting 3 primary bark beetle species. We also investigated how predator abundance and flight seasonality related to those of 5 bark beetle species: lps pini (Say), I. lecontei Swaine, Dendroctonus frontalis Zimmermann, D. brevicomis LeConte, and D. adjunctus Blandford. Temnochila chlorodia was most abundant in the low- and mid-elevation bands, whereas E. sphegeus was most abundant in the high-elevation band. Enoclerus lecontei showed no consistent elevational trend in abundance. Within each elevation band, changes in annual abundance of pooled predator species tracked shifts in abundance of pooled bark beetle species. In general, predator flight initiation coincided with or closely followed bark beetle flight initiation in the spring, but predator flight terminated before flight activity ended for most bark beetle species in the fall. In addition, the ratio of prey to predators was lowest in the summer and highest in the fall. This suggests that all bark beetle species examined may be provided temporal escape from their predators in the fall. For all 3 predator species, the pheromone-baited trap targeting D. brevicomis was less attractive than the pheromone-baited traps targeting I. pini and I. lecontei.

Only a single previous study has examined ectoparasites of the occult bat (Myotis occultus), from which only 2 species of fleas were identified. For our study, we examined 202 individuals, 52 fresh hosts and 150 museum specimens, from New Mexico and southern Colorado for ectoparasites. We recorded 2158 ectoparasites, 634 from fresh hosts and 1524 from museum specimens. Ectoparasites belonged to 10 families and 13 genera of insect or acari and represent new host and locality records. In general, ectoparasites collected from fresh hosts and museum specimens were represented by 4 major species of mite: Macronyssus crosbyi, Alabidocarpus calcaratus, Acanthophthirius lucifugus, and Alabidocarpus nr. eptesicus. From our study, we found fresh hosts to have significantly greater prevalence values for Myodopsylla gentilis (flea), Chiroptonyssus robustipes (mite), and Leptotrombidium myotis (chigger), whereas museum specimens had significantly greater prevalence values for A. calcaratus (mite) and A. nr. eptesicus (mite). There were no significant differences between prevalence values for 4 mites including M. crosbyi, A. lucifugus, Pteracarus nr. minutus, and Cryptonyssus sp. Our study represents the only extensive study of ectoparasites on M. occultus and provides evidence for the importance of examining fresh hosts and museum specimens in future ectoparasite studies.

We evaluated the effects of various density treatments on adult fish growth and emigration rates between Bonneville cutthroat trout Oncorhynchus clarki utah and brook trout Salvelinus fontinalis in stream enclosures in Beaver Creek, Idaho, We used 3 density treatments (low, ambient, and high fish densities) to evaluate density-related effects and to ensure a response. Intraspecific ambient-density tests using cutthroat trout only were also performed. Results indicated an absence of cage effects in the stream enclosures and no differences in fish growth between ambient-density stream-enclosure fish and free-range fish. Brook trout outgrew and moved less than cutthroat trout in the stream enclosures, especially as density increased, In all 3 density treatments, brook trout gained more weight than cutthroat trout, with brook trout gaining weight in each density treatment and cutthroat trout losing weight at the highest density. At high densities, cutthroat trout attempted to emigrate more frequently than brook trout in sympatry and allopatry. We observed a negative correlation between growth and emigration for interspecific cutthroat trout, indicating a possible competitive response due to the presence of brook trout. We observed similar responses for weight and emigration in trials of allopatric cutthroat trout, indicating strong intraspecific effects as density increased. While cutthroat trout showed a response to experimental manipulation with brook trout at different densities, there has been long-term coexistence between these species in Beaver Creek, This system presents a unique opportunity to study the mechanisms that lead cutthroat trout to coexist with rather than be replaced by nonnative brook trout.

We report observations on reproductive phenology, fecundity, and sporocarp morphology for a population of the semiaquatic fern Marsilea mollis B.L. Rob. & Fernald in southern Arizona and document the parasitic relationships of 2 insects collected with the plants. The recently described weevil Notiodes sporocarpicus O'Brien (Coleoptera: Curculionidae) utilizes the fern's sporocarp as a brood chamber, only the second documented instance of this form of parasitism in the United States. The wasp Lyrcus maculatus (Gahan) (Hymenoptera: Pteromalidae) is a parasitoid of the weevil in this system.

The long-tailed vole (Microtus longicaudus) exhibits karyotypic variation in western North America. In the American Southwest, the species has a disjunct, relict distribution. However, karyotypes obtained from 20 specimens in 5 isolated mountain ranges (White Mountains, Arizona; Mount Taylor and the Sangre de Cristo, Jemez, and Mogollon mountains, New Mexico) exhibited no variation. These and previously reported karyotypes from the region had a diploid number (2n) of 56 and fundamental number (FN) of 84, which is the most commonly reported karyotype for the species.

Mearn's grasshopper mouse (Onychomys arenicola) in Mexico is found primarily in the central and northern states. This is the first report of the genus Onychomys in the state of Veracruz, based on 7 captured specimens (3 collected). This finding extends the species' known distribution by approximately 470 km east-southeast. In addition, this record increases the alpha diversity of terrestrial mammals for the state of Veracruz to 192 species.

Eastern pipistrelles (Perimyotis subflavus) were first documented from South Dakota, western Texas, and New Mexico during recent years, suggesting that the distribution of this species is expanding westward across central parts of North America. In New Mexico, only 2 records of P. subflavus previously were known—one from summer and one from autumn. Here we report on 3 new records of P. subflavus from southeastern New Mexico, including the first 2 records from winter and the first record from spring. One individual in winter was observed hibernating in a cave in Chaves County. Our records and previous ones from autumn and summer suggest that this species is resident throughout the year in New Mexico.

Despite its large geographic range, little is known about reproductive traits in the northern scorpion (Paruroctonus boreus). We analyzed reproductive traits for 36 females from a population near Billings, Montana. All data were collected within a single year. Litter size, offspring mass, total litter mass (TLM), and relative litter mass (RLM) were within the ranges of values reported for other species in the Vaejovidae. Female size (length or mass) was not correlated with any reproductive trait. Litter size and offspring mass were each positively correlated with RLM, suggesting that females investing relatively larger amounts of energy in reproduction increase both size and number of offspring. Finally, the within-litter coefficient of variation in offspring mass was negatively correlated with RLM, TLM, and mean offspring mass, suggesting that females investing more energy in reproduction produce more-uniformly sized offspring, an observation that appears common in scorpions.

An antlerless mule deer (Odocoileus hemionus) was collected on 2 December 1992 from an established Oak Creek mule deer herd 2 miles north of Oak City, Utah (Utah Wildlife Receipt #027604). Upon examination, the animal had prominent male genitalia with hair rubbed off from the pedicle part of the skull, Tissue examination revealed active spermatogenesis and viable sperm in the lumen of the epididymis and testis. Antlerless male deer have been reported previously in this area, but this is the first histological study of the abnormal deer, Lack of antlers would be advantageous for male deer during the hunting season because most western states limit deer harvest to antlered bucks.

Water sources are an important habitat component for populations of bighorn sheep (Ovis canadensis), and the technique of sampling at water sources has been used extensively to study behaviors and estimate parameters of bighorn populations, Little is known, however, concerning the time of day at which groups of bighorns visit water. Understanding when bighorns visit water sources will allow wildlife investigators to conduct sampling when bighorns are most likely to be present at this resource. We quantified use of 7 water sources by reintroduced bighorn sheep during summer 2005 and 2006 on Antelope Island State Park, Utah. Our purpose was to determine if female, male, or mixed-sex groups visited water at a particular time and if visits to this resource by all bighorns differed in time during drought conditions compared with nondrought conditions. The mean time that all bighorns visited water was 14:22 (s = 3:08 hours). No time differences existed among female, male, or mixed-sex groups or between drought and nondrought conditions. Our results provide wildlife investigators with a time frame for activating motion-sensor cameras or sampling at water sources, which will increase the likelihood of photographing or observing reintroduced Rocky Mountain bighorn sheep at water sources in portions of the Great Basin Desert.

Greater Sage-Grouse (Centrocercus urophasianus) is a species of concern, and accurate population data are needed to monitor conservation management efforts. Conventional, ground-based lek counts are labor-intensive, expensive, and have several sources of potential error and bias, including the practical limits on number and distribution of leks counted. We tested aerial methods for photographing multiple leks during a single morning. We completed 14 aerial approaches to 6 leks in 2 different years using 2 different airplanes and altitudes. Grouse flushed from leks on 12 approaches when the airplane was within 200–300 m of the lek. In 2 instances, strutting grouse crouched and stayed on the lek. Our highest-resolution images increased our confidence in grouse identification but also decreased field-of-view coverage to the detriment of count accuracy. The methods we tested do not allow sage-grouse to be accurately counted, but the results provide information about sage-grouse responses to low-altitude airplane approaches and about useful image resolutions and fields of view.