12 research outputs found

    Bat Use, Human Visitation, and Environmental Attributes of Cave Hibernacula in Montana

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    Across the eastern United States, caves historically supported large aggregations of overwintering bats. In contrast, few large aggregations have been observed within caves in Montana. To collect comprehensive information on cave use by bats and inform White Nose Syndrome surveillance, we inventoried caves to estimate numbers of hibernating bats, assessed the microclimate within hibernacula, monitored activity of bats using acoustic detectors, and quantified visitation by people using trail cameras. In collaboration with recreational cavers, state, and federal biologists we conducted over 300 structured and incidental surveys at 99 caves.  Only 6 caves had counts exceeding 100 individuals, and our largest hibernacula had approximately 1,700 bats. The mean annual temperature and humidity across 16 caves averaged 5.0°C and 100% RH. At the 6 largest hibernacula, we established year round baselines of bat acoustic activity and quantify visitation by people. We found that both the number of people entering caves and bat activity within caves peaked in summer. During the winter, visitation appears largely dependent on accessibility of the cave and all monitored caves had low levels of bat activity. Caves in Montana appear to support relatively few aggregations of overwintering bats. Although we have visited most known caves in the state, the number of hibernating individuals we observed is likely orders of magnitude less than the total number we presume overwinter in-state. Future projects should explore the use of cracks, crevices, talus, and badlands to identify other important hibernacula

    Acoustic Assessment of Year-round Bat Activity and Distribution in Montana and Surrounding Areas

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    Montana’s bat species face an array of conservation issues including wind energy development and disease. A collaborative project between state and federal agencies was initiated in 2011 to collect baseline data prior to the arrival of White-nose Syndrome and help inform surveillance and future mitigation strategies. In the last 6 years, we deployed a network of Song Meter ultrasonic acoustic detector/recorder stations at 76 sites across the region for an average of 1.8 years per station. Each detector recorded nightly bat passes across all seasons. To date 9.5 million sound files have been recorded. Using automated scrubbing and identification software we identified call sequences and generated initial species identifications, then hand confirmed species presence by month at each site. Over 54,000 bat passes have been reviewed by hand and used to track activity of all species at each site. To date we have 2,770 new records of monthly species presence, regular winter activity of 3 resident species, and year-round presence of 1 species previously considered migratory. Through integrating National Oceanographic and Atmospheric Association weather station with our call data, we have found positive correlations in activity with temperature and barometric pressure, and negative correlations with wind speed. Our experiences with these data highlight the importance of: (1) maintaining common settings across recording devices and consistent processing standards; (2) maintaining publicly available call libraries that can be reanalyzed using the latest software and made available to software developers; and (3) making standards used for species determinations available for peer review

    Rediscovery of the Northern Myotis in Montana

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    The Northern Myotis aka: Northern Long-eared Bat (Myotis septentrionalis, NLEB) may be among the rarest mammal species within Montana. Prior to 2016 its presence in the state was known from a single male collected from an abandoned coal mine south of Culbertson, MT in the winter of 1978. In 2015 this species was listed as Threatened under the Endangered Species Act because of significant declines in eastern populations due to White-Nose Syndrome (WNS). To provide information about the presence and distribution of this species within the state, we conducted mist netting surveys in 2015 and 2016 across 9 counties designated by the US Fish and Wildlife Service as part of the NLEB’s range. In 2015, forested uplands and deciduous forest were targeted over 11 nights. In 2016, we targeted deciduous forest along major river drainages for 23 nights. We captured 3 NLEBs at 2 sites in 2016 and 0 in 2015.  All Myotis species were genetically confirmed. Individuals were captured at 2 sites along the Missouri river in proximity to the previous detection in Montana and historic records in North Dakota.  Both females and the male were reproductive, indicating that this species may breed within the state. However, given the close proximity to the border of the female captures, we cannot definitively say whether these animals roost in North Dakota or Montana.  In addition to captures of NLEBs we also established records for several WNS susceptible species, providing valuable pre-WNS baseline information on bats in this region

    In-Hand Measurements of Adult Bats in the Northern Great Plains and Rocky Mountains

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    Researchers rely on keys and other published records of pelage and morphological characteristics to identify bat species in the field. However, these records may not reflect the variability of measurements taken in a field setting, particularly if they are based upon museum specimens or a small number of live individuals. To assist in the identification of similar bat species, we created a supplement to the “Key to Idaho, Montana, and South Dakota Bats.” We compiled 3,222 records of 11 species of adult bats captured between 1994-2016 in Montana, northern Idaho, and northwestern South Dakota. Using this dataset, we have provided distributions of body measurements as well as insight into the timing of reproduction, parturition, and seasonal body condition for 14 of the 15 species occurring within Montana. Following data analyses, we concluded that: (1) lengths of smaller appendages such as the thumb and tragus show substantial variation, demonstrating that more precise measurements are required; (2) parturition dates appear similar across all species present in the study area, including migratory bats; (3) trends of low body mass in late summer captures may represent older juveniles that are difficult to distinguish from adults by current methods;  and (4) we require more data to analyze the traits of species that are infrequently captured. This document will be available on the Montana Natural Heritage Program website (mtnhp.org) to assist researchers in the field

    Can Montana Shrews be Identified using Morphology of Dorsal Guard Hairs?

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    Several species of shrews present in Montana are considered species of concern by state and federal agencies, primarily due to a lack of information. Current methods for identifying shrew species can be costly, potentially inaccurate, and logistically challenging. We sought to validate a novel methodology developed in the United Kingdom that uses morphological characteristics of dorsal guard hairs for identification of shrew species. Utilizing museum collections at Montana State University and the University of Montana, we sampled dorsal guard hairs from specimens of Montana shrews with known identities. We measured four length and width characteristics for each hair sample and used a discriminate function analysis to calculate the probability of correctly identify a specimen to species. We achieved >80% confidence identifying the pygmy shrew (Sorex hoyi), which is a species of concern in Montana, and >70% confidence identifying the Northern short-tailed shrew (Blarina brevicauda). To increase our ability to discriminate between species we analyzed subsets of species found within discrete ecoregions and habitats. Within these subsets we achieved >80%confidence identifying the masked shrew (S. cinereus), and >60% confidence identifying the dwarf shrew (S. nanus). These findings suggest that this new methodology is viable for some species and can provide a simple, affordable research tool for the targeted study of shrews in Montana

    Baseline Indices for Calling Amphibians and Western Toads Across Montana

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    Amphibian populations are undergoing global decline, and nearly one-third of the world’s amphibian species are threatened.  Structured surveys can use a variety of invasive and noninvasive techniques to assess the status of a species while repeatable surveys allow for longterm monitoring to identify population trends.  To establish baselines for species occupancy and indices for abundance we conducted two projects to inventory amphibians during May and June of 2016.  We conducted roadside calling surveys for species that advertise breeding through calls and lentic surveys at known breeding locations of the Western Toad (Anaxyrus boreas).  Roadside surveys were broken into west and east regions based on species distributions.  We detected two species at seven of the eight western transects, Pacific Tree Frog (Pseudacris regilla) and American Bullfrog (Lithobates catesbeianus).  The Pacific Tree Frog was identified at 19% of the stations sampled, but at low densities.  In the east, we detected five species of amphibians at 18 of the 19 transects, Boreal Chorus Frog (P. maculate), Northern Leopard Frog (L. pipiens), Great Plains Toad (A. cognatus), Woodhouse’s Toad (A. woodhousii), and Plains Spadefoot Toad (Spea bombifrons).  The Boreal Chorus Frogs were most commonly detected (39%) followed by Woodhouse’s Toad (13%) and Plains Spadefoot (12%).  Of the 76 sites we surveyed for Western Toad, 63% had evidence of breeding.  These surveys can be used as primary indices for future surveys to determine trends in abundance and occupancy through time and inform state status ranks

    Minutes of the QCD Meetings on 21 July, 3 September, 17 September, and 30 September 1992

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    Many parasites infect multiple hosts, but estimating the transmission across host species remains a key challenge in disease ecology. We investigated the within and across host species dynamics of canine distemper virus (CDV) in grizzly bears (Ursus arctos) and wolves (Canis lupus) of the Greater Yellowstone Ecosystem (GYE). We hypothesized that grizzly bears may be more likely to be exposed to CDV during outbreaks in the wolf population because grizzly bears often displace wolves while scavenging carcasses. We used serological data collected from 1984 to 2014 in conjunction with Bayesian state‐space models to infer the temporal dynamics of CDV. These models accounted for the unknown timing of pathogen exposure, and we assessed how different testing thresholds and the potential for testing errors affected our conclusions. We identified three main CDV outbreaks (1999, 2005, and 2008) in wolves, which were more obvious when we used higher diagnostic thresholds to qualify as seropositive. There was some evidence for increased exposure rates in grizzly bears in 2005, but the magnitude of the wolf effect on bear exposures was poorly estimated and depended upon our prior distributions. Grizzly bears were exposed to CDV prior to wolf reintroduction and during time periods outside of known wolf outbreaks, thus wolves are only one of several potential routes for grizzly bear exposures. Our modeling approach accounts for several of the shortcomings of serological data and is applicable to many wildlife disease systems, but is most informative when testing intervals are short. CDV circulates in a wide range of carnivore species, but it remains unclear whether the disease persists locally within the GYE carnivore community or is periodically reintroduced from distant regions with larger host populations
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