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

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

Baseline Indices for Calling Amphibians and Western Toads Across Montana

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

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

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

Evaluation of indicators of environmental sensitivity with respect to bats and their native habitats near Albeni Falls Dam and Lake Pend Oreille, Idaho /

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

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

Long-term acoustic assessment of bats at coal mines across Southcentral Montana and management recommendations for bats /

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A review of bat hibernacula across the western United States: Implications for white-nose syndrome surveillance and management

Efforts to conserve bats in the western United States have long been impeded by a lack of information on their winter whereabouts, particularly bats in the genus Myotis. The recent arrival of white-nose syndrome in western North America has increased the urgency to characterize winter roost habitats in this region. We compiled 4,549 winter bat survey records from 2,888 unique structures across 11 western states. Myotis bats were reported from 18.5% of structures with 95% of aggregations composed of ≤10 individuals. Only 11 structures contained ≥100 Myotis individuals and 6 contained ≥500 individuals. Townsend’s big-eared bat (Corynorhinus townsendii) were reported from 38% of structures, with 72% of aggregations composed of ≤10 individuals. Aggregations of ≥100 Townsend’s big-eared bats were observed at 41 different caves or mines across 9 states. We used zero-inflated negative binomial regression to explore biogeographic patterns of winter roost counts. Myotis counts were greater in caves than mines, in more recent years, and in more easterly longitudes, northerly latitudes, higher elevations, and in areas with higher surface temperatures and lower precipitation. Townsend’s big-eared bat counts were greater in caves, during more recent years, and in more westerly longitudes. Karst topography was associated with higher Townsend’s big-eared bat counts but did not appear to influence Myotis counts. We found stable or slightly-increasing trends over time in counts for both Myotis and Townsend’s big-eared bats from 82 hibernacula surveyed ≥5 winters since 1990. Highly-dispersed winter roosting of Myotis in the western USA complicates efforts to monitor population trends and impacts of disease. However, our results reveal opportunities to monitor winter population status of Townsend’s big-eared bats across this region