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In communities where they occur, American badgers (Taxidea taxus) play important ecological, economic, and conservation roles. Central to understanding of badger ecology and management are estimates of badger population status. However, few studies have compared methods of detecting badgers for population surveys. I compared searches for burrows and diggings, live-trapping, and the use of automatic cameras at scent lures, bait stations, and anthropogenic permanent and temporary wildlife water sources in the Chihuahuan Desert of southern New Mexico. Searches for confirmed badger burrows and diggings yielded 0.14–0.88 detections per kilometer of transect. Badgers were trapped in 1.6% of trap-weeks. Percentages of camera-weeks in which badgers were detected included 12.8% at scent lures, 5.6% at bait stations, 54.5% at permanent water sources, and 13.3% at temporary water sources.
In the northern U.S. Rockies, including the Greater Yellowstone Ecosystem (GYE), connectivity is a concern because large carnivores have difficulties dispersing successfully between protected areas. One area of high conservation value because of its importance for connecting the GYE to wilderness areas of central Idaho is the Centennial Mountains and surrounding valleys (2500 km2) along the Idaho—Montana border just west of Yellowstone National Park. The current expansion of grizzly bears (Ursus arctos) and other large carnivore populations outside protected areas of Yellowstone National Park and Grand Teton National Park has placed a greater emphasis on potential linkage zones in the northern Rockies. Here we use black bears (Ursus americanus) as a test case to demonstrate the utility of using detection dogs and DNA analysis coupled with resource selection probability function (RSPF) models to examine habitat suitability for large carnivores in critical linkage zones. Detection dogs specifically trained to locate the scat of black bears and grizzly bears were used to sample the study area. Here we report the RSPF results for black bears and discuss the utility of detection dogs for sampling species of carnivores to undertake similar analyses. Utilizing location data from genetic analysis of 616 fecal samples for black bears, we developed a RSPF model to examine use of the landscape with respect to habitat parameters, public land management, private lands, and human activities. The most parsimonious model determining probability of use for black bears included parameters for elevation, coniferous forest, land stewardship, road density, distance to roads, and an interaction between human population density and road density at the scale of 500 m. The model identified specific core-habitat areas in the region that potentially are crucial for the Yellowstone population of grizzly bears as it expands into areas west of Yellowstone National Park. Here we demonstrate that detection dogs are a useful method for sampling large carnivores and, when coupled with genetics and RSPF models, offer an effective approach to addressing questions of habitat suitability in areas of high conservation importance.
The current classification of Ptelea divides the widespread and highly variable Ptelea trifoliata L. into 5 subspecies and 11 varieties, while additionally terming many specimens “intermediate.” Although there are visually observable differences among regional variants, principal component analyses of quantitative characters failed to separate subspecies or to even incompletely separate most varieties within subspecies. Some recognized subgroups are also not well distinguished by discontinuous qualitative characters. Where multiple varieties appear to be part of a single continuum of variation or are extremely similar, it is suggested that a reduction in the number of infraspecific taxa would improve the utility of the classification. An alternative classification recognizing 5 subspecies and 7 varieties is accordingly proposed.
American pikas (Ochotona princeps) are of concern with respect to warming montane temperatures; however, little information exists regarding their physiological ability to adapt to warming temperatures. Previous studies have shown that pikas have high metabolism and low thermal conductance, which allow survival during cold winters. It has been hypothesized that these characteristics may be detrimental, given the recent warming trends observed in montane ecosystems. We examined resting metabolic rate, surface activity, and den and ambient temperatures (Ta) of pikas in late summer (August 2011 and 2012) at 2 locations in the Rocky Mountains. Resting metabolic rate was calculated to be 2.02 mL O2 · g-1h-1, with a lower critical temperature (LCT) of 28.1 ± 0.2 °C. No upper critical temperature (UCT) could be determined from our data; therefore, the estimated thermoneutral zone (TNZ) was 28.1 °C to at least 35.0 °C (upper experimental temperature). Pikas in this study showed the same bimodal above-talus activity patterns reported in previous studies. Den temperatures in Colorado were correlated with, but consistently lower than, current ambient temperatures. Wyoming den temperatures showed a weak correlation with Ta 20 min prior to the current den temperature. This study is one of few to present data on the physiological response pikas may have to current warming conditions, and the first to perform metabolic measurements in situ. Our data support conclusions of previous studies, specifically MacArthur and Wang (1973, 1974) and Smith (1974), which indicated American pikas may not have the physiological ability to cope with high Ta. Our results also highlight the importance of shaded regions below the talus rocks for behavioral thermoregulation by pikas.
Nutrient content and weight of current year's growth of Cercocarpus ledifolius Nuttall and Physocarpus malvaceus (Greene) Kuntze in central Idaho were obtained during early July in the years 1987–2007. The purpose of this work was to determine whether there was significant variation between years and whether mean monthly temperatures and total monthly precipitation could predict the variation. A wildfire in August 2000 caused P. malvaceus to vigorously resprout. Significant differences between years occurred for all nutrients for both species. October temperatures best predicted weight of current year's growth in C. ledifolius, whereas prediction equations for nutrients involved spring temperatures and precipitation, primarily for June. January mean temperature and December precipitation best predicted weight of current year's growth, and spring mean monthly temperatures best predicted nutrient levels in P. malvaceus. Future changes in production and nutrient content of these species that are not predicted may be related to climate change.
Fringed myotis (Myotis thysanodes) is a bat species of conservation concern in western North America that may be impacted by increased recreational activity near roost sites, changes in water resource availability caused by increased urban and agricultural water use, and anthropogenic climate change. Our purpose was to describe and model maternity roost use by fringed myotis in Colorado. We compared differences between roosts occupied by maternal fringed myotis and randomly selected potential roosting locations that were not known to be occupied by this species during the maternity period. We evaluated the strength of evidence for competing hypotheses on 2 scales: one that included landscape variables and a second that included roost-site variables. We used logistic regression, Akaike's information criterion, and multimodel inference to investigate maternity roost use by fringed myotis. The model explaining the most variability in our landscape data included grade and aspect, and the model explaining the most variability in our roost-site data was estimated volume of the roost. Understanding maternity roost use by fringed myotis can guide conservation and management decisions related to roost protection in the Rocky Mountain West. When feasible, we believe that developing knowledge about maternity roost use, as well as autumn and winter roost use, will help improve management decision making related to forest bats of conservation concern in western North America.
Several species of fishflies (Megaloptera: Corydalidae: Chauliodinae) have been reported from intermittent streams in western North America, but the life histories and distributions of these species are poorly understood. We studied the life history of Neohermes filicornis (Banks 1903) for 2 years in Donner Creek (Contra Costa County, California), a small intermittent stream that flows for 5–7 months per year. Neohermes filicornis had a 3–4-year life span and larval growth was asynchronous. Analysis of gut contents showed that larvae were generalist predators of aquatic insect larvae including Diptera, Ephemeroptera, and Plecoptera. Final instars dug pupal chambers in the streambed and began pupation within several days of stream drying. Dry conditions in 2007 resulted in stream drying 50 days earlier than in 2006, which was reflected in earlier pupation and adult emergence in 2007 than in 2006. Pupal and adult stages each lasted for 1–2 weeks. Although active burrowing into the dry streambed was not observed in the field, N. filicornis larvae initiated burrowing in response to simulated stream drying in laboratory experiments, while Orohermes crepusculus (Chauliodinae), a fishfly species common in perennial streams, did not exhibit burrowing behavior. We present new and historic collection records for Neohermes spp. in western North America. Neohermes filicornis is distributed in California, Arizona, western New Mexico, Baja California, and Sonora. A sister taxon, Neohermes californicus, has been collected in California, Oregon, and Idaho. In California, N. filicornis is primarily distributed in the Coast Range and mountains of Southern California, whereas N. californicus occurs in the foothills of the Sierra Nevada, with possible range overlap at the northern and southern ends of the Central Valley. As a long-lived aquatic insect, N. filicornis exhibits considerable plasticity in the phenology of its life cycle and undergoes multiple episodes of larval dormancy in intermittent streams of western North America.
Across the western United States, Leporidae are the most important prey item in the diet of Golden Eagles (Aquila chrysaetos). Leporids inhabiting the western United States include black-tailed (Lepus californicus) and white-tailed jackrabbits (Lepus townsendii) and various species of cottontail rabbit (Sylvilagus spp.). Jackrabbits (Lepus spp.) are particularly important components of the ecological and economic landscape of western North America because their abundance influences the reproductive success and population trends of predators such as coyotes (Canis latrans), bobcats (Lynx rufus), and a number of raptor species. Here, we review literature pertaining to black-tailed and white-tailed jackrabbits comprising over 170 published journal articles, notes, technical reports, conference proceedings, academic theses and dissertations, and other sources dating from the late 19th century to the present. Our goal is to present information to assist those in research and management, particularly with regard to protected raptor species (e.g., Golden Eagles), mammalian predators, and ecological monitoring. We classified literature sources as (1) general information on jackrabbit species, (2) black-tailed or (3) white-tailed jackrabbit ecology and natural history, or (4) survey methods. These categories, especially 2, 3, and 4, were further subdivided as appropriate. The review also produced several tables on population trends, food habits, densities within various habitats, and jackrabbit growth and development. Black-tailed and white-tailed jackrabbits are ecologically similar in general behaviors, use of forms, parasites, and food habits, and they are prey to similar predators; but they differ in their preferred habitats. While the black-tailed jackrabbit inhabits agricultural land, deserts, and shrublands, the white-tailed jackrabbit is associated with prairies, alpine tundra, and sagebrush-steppe. Frequently considered abundant, jackrabbit numbers in western North America fluctuate temporally and spatially. We also reviewed methods used to investigate jackrabbit populations, including spotlight line transects, flushing transects, drive counts, pellet plot counts, collections, roadside counts, mark-recapture studies, and radio-telemetry studies. Our review of jackrabbit literature illustrates a number of deficiencies in our understanding of jackrabbits in general. As an example, a detailed quantitative description of habitat preferences is lacking, as is a thorough understanding of sympatric jackrabbit species interactions. Even the existence of the oft-cited jackrabbit “cycle” is a matter of debate. Survey methods generally do not address efficacy or accuracy in measuring jackrabbit density or abundance. In addition, there is a paucity of information about jackrabbits in the Mojave Desert, with no real understanding of home ranges, habitat preferences, and population dynamics or demographics in this region.
We documented the first record of jaguar (Panthera onca) in the state of Hidalgo, México. With this record, the gap in the distribution of jaguar between San Luis Potosí and northwestern Puebla is reduced. In July 2013, we found 2 tracks on a trail in a pine-oak forest, and in October, we photographed a jaguar in an oak forest. Both sites are located within the Parque Nacional Los Mármoles in Sierra Gorda of Hidalgo. These records represent the first evidence of the presence of jaguar in Hidalgo, which is among the few states where all 6 species of felids that inhabit México occur.
Much of the western United States is managed by state and federal agencies for multiple uses, including recreation, grazing, extraction, and defense. Biological inventories are integral to proper management and conservation of biodiversity on these lands. We surveyed for amphibians and reptiles occurring on Naval Air Station Fallon (NAS Fallon), Nevada, USA, using a variety of methods. We documented the presence of a majority of the amphibian and reptile species native to this region of the Great Basin. We found 5 species on NAS Fallon that are listed as Species of Conservation Priority by the Nevada Department of Wildlife: the Great Basin Spadefoot (Spea intermontana), Western Toad (Anaxyrus boreas boreas), Northern Desert Horned Lizard (Phrynosoma platyrhinos platyrhinos), Long-nosed Leopard Lizard (Gambelia wizlizenii), and Great Basin Collared Lizard (Crotaphytus bicinctores). However, we found no evidence of any narrowly distributed species of conservation concern, such as the Northern Leopard Frog (Lithobates pipiens) or Northern Rubber Boa (Charina bottae), that could have occurred on installation lands based on historical or recent observations in nearby areas. Our results indicate that this property, while primarily used for military training, can support a diverse, representative herpetofaunal community. Therefore, NAS Fallon should be considered a valuable part of the network of state and federally managed lands necessary for regional conservation planning in the face of future change. Our study also provides a baseline against which future inventories of this federally managed land can be compared.
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