Colorado bat conservation plan (original) (raw)
Related papers
Guidelines for Defining Biologically Important Bat Roosts: A Case Study from Colorado
Journal of Fish and Wildlife Management, 2017
Conservation of roosts is regularly recommended as a strategy to decrease the risk of threats to local bat populations (e.g., white-nose syndrome). Determining whether a roost site plays a meaningful role in maintaining a local bat population can be difficult given the variability found in roost structure type, and use by season, duration, and sex. Here we provide land managers and biologists with guidelines to aid in the decision process for determining which roosts are biologically important in maintaining healthy bat populations at a local scale. We define methods for determining biologically important roost sites and provide a case study of their use on bat roosts in Colorado. To be considered biologically important, we suggest that a roost meet two primary criteria: 1) it is considered a hibernaculum, maternity roost, transient roost, colonial bachelor roost, or fall swarming site used by bat species that are gregarious roosters, hibernators, or are known to swarm, and 2) if th...
1998
work was bat use of Azure Cave, the largest bat hibernaculum in the state and one of the largest in the Pacific Northwest and Northern Rocky Mountains regions. Three rock-shelter caves were also evaluated for bat use. Three hibernation counts in Azure Cave (April 1997 and 1998, November 1998), and two trapping sessions at the mouth of Azure Cave (October 1997, September 1998), were conducted during the study. Counts of hibernating bats in Azure Cave indicated a significant increase since 1978, the first count available for the cave, and the only complete count for the hibernation period. In April 1978, maximum count was 528. Mean counts in April 1997 and 1998 were 1246 and 1120, respectively. Mean count in November 1998 was 1604. Four species of bats were documented in Azure Cave in 1997-1998: Townsend's Big-eared Bat (Corynorhinus townsendii), Big Brown Bat (Eptesicus fuscus), Little Brown Myotis (Myotis lucifugus), Long-legged Myotis (Myotis volans). Most use continues to be by species of Myotis. Two nights of netting in October 1997 at the mouth of Azure Cave resulted in capture of 15 bats of three species: Townsend's Big-eared Bat (1), Big Brown Bat (13), Little Brown Myotis (1). Two of the Big Brown Bats were recaptured males marked at the cave in October 1996. Two nights of netting at the cave in September 1998 resulted in capture of 150 bats of six species: Townsend's Big-eared Bat (2), Big Brown Bat (49), Little Brown Myotis (82), Longlegged Myotis (10), Western Small-footed Myotis (Myotis ciliolabrum) (3), Western Long-eared Myotis (Myotis evotis) (4). One male Big Brown Bat, marked at the cave in October 1996, was present in this sample. Significantly more males were present in netting samples of Big Brown Bat, Little Brown Myotis, and Long-legged Myotis, species for which sample sizes were largest. Within species, especially Little Brown Myotis and Big Brown Bats, mean weights in September were greater than in June or July. For Big Brown bats, weight declined in October, perhaps indicating that late-flying individuals were still attempting to gain fat reserves prior to hibernation. Alternatively, they may have been seeking additional opportunities for mating at the expense of accumulated fat stores. Evidence of bat use was found in two of three rock-shelter caves examined. These caves were shallow (21 m maximum depth), and are most likely used as night roosts. Numerous other limestone pockets and rock-shelter caves, as yet unexamined for bat sign, could be used by bats. Most old mine workings are no longer accessible to bats, but a few could provide significant habitat and merit further examination. Most caves and mines of any size in the Little Rocky Mountains are too cold for use as maternity roosts by bats. To date, seven species of bats (the six previously listed plus the Hoaiy Bat. Lashirus cinereus) have been verified in the Little Rocky Mountains, and an additional species (Silverhaired Bat, Lasionycteris noctivagans) has been reported, based on vocal recordings. A summary of all records for each species is provided. Unauthorized human entiy into Azure Cave, especially if it occurs during the period of occupancy, continues to be a management concern for protection of the bats using the cave as a hibernaculum. Means to improve security of the gate (while maintaining accessibility for bats), and regular visits to Azure Cave to check on gate integrity, should be considered. ni ACKNOWLEDGMENTS This project was made possible through support of the Montana Natural Heritage Programa collaborative effort of The Nature Conservancy and the Natural Resource Information Systemand a Challenge Cost Share agreement with the (former) Lewistown District, Bureau of Land Management. Michelle Williams and Dave Genter secured the initial contract that got this project going. Tim Novotny supervised the supplemental contract that covered the field work reported herein.
State of Washington bat conservation plan
This is the Washington State Bat Conservation Plan. It gives an overview of bat biology, habitat requirements, relationships to public health, legal and conservation status, conservation and management activities, and known or potential threats to bats. The plan summarizes the historical and current distribution and abundance of each of the 15 bat species found in Washington, with information also provided on identification, taxonomy, habitat, natural history, threats, and conservation measures. The plan also outlines strategies and tasks needed to implement conservation and protection of bats in Washington.
Bats of Mesa Verde National Park, Colorado: Composition, Reproduction, and Roosting Habits
Monographs of the Western North American Naturalist, 2011
We determined the bat fauna at Mesa Verde National Park (Mesa Verde) in 2006 and 2007, characterized bat elevational distribution and reproduction, and investigated roosting habits of selected species. We captured 1996 bats of 15 species in mist nets set over water during 120 nights of sampling and recorded echolocation calls of an additional species. The bat fauna at Mesa Verde included every species of bat known west of the Great Plains in Colorado, except the little brown bat (Myotis lucifugus). Some species showed skewed sex ratios, primarily due to a preponderance of males. Thirteen species of bats reproduced at Mesa Verde. Major differences in spring precipitation between the 2 years of our study were associated with differences in reproductive rates and, in some species, with numbers of juveniles captured. Reduced reproductive effort during spring drought will have a greater impact on bat populations with the forecasted increase in aridity in much of western North America by models of global climate change. We radiotracked 46 bats of 5 species to roosts and describe the first-known maternity colonies of spotted bats (Euderma maculatum) in Colorado. All 5 species that we tracked to diurnal roosts relied almost exclusively on rock crevices rather than trees or snags, despite the presence of mature forests at Mesa Verde and the use of trees for roosts in similar forests elsewhere by some of these species. Comparisons with past bat surveys at Mesa Verde and in surrounding areas suggest no dramatic evidence for effects of recent stand-replacing fires on the composition of the bat community.
Bat Habitat Use in White Mountain National Forest
Journal of Wildlife Management, 1996
In 1992 and 1993, we surveyed the foraging and feeding activity of bat species with broadband bat detectors at 2 foliage heights in 4 age classes of northern hardwood and spruce/fir forest stands in White Mountain National Forest, New Hampshire and Maine. The association of bat activity with trails and water bodies and the effect of elevation were measured. Mist nets, a harp trap, and ultrasonic detectors were used to establish species presence. Bat activity was concentrated at trail and water body edges and was uniform within a forest stand at the same sampling height. Within the forest, bat activity was highest in overmature (>l19 yr, 35% of mean bat activity/night) hardwood stands and in regenerating (0-9 yr) stands of both forest types (26% of mean bat activity /night). The majority of bats trapped (56%) were adult male little brown bat (M yotis lucifugus). Our data indicate that a matrix of forest types and age classes including areas of regeneration (clearcuts and group cuts) and overmature hardwood, in combination with trails and water bodies, help fulfill the summer habitat requirements of bats in White Mountain National Forest.
Distribution and ecology of bats of Colorado
1994
Eighteen species of bats in the families Vespertilionidae and Molossidae are documented from Colorado. Accounts of species include information on foraging and roosting habitat, status and abundance, activity patterns, and reproduction. Records of occurrence are mapped based on examination of some 21 10 specimens and review of literature. Summary analyses of population and community ecology, zoogeography, and public health provide a basis for review of conservation and management issues.
An Overview: The North American Bats and Mines Project
2002
Bat Conservation International (BCI) and the United States Bureau of Land Management founded the North American Bats and Mines Project in 1993 to provide national leadership and coordination to minimize the loss of mine-roosting bats. BCI utilizes a cooperative and non-confrontational approach to resolving natural resource management conflicts and builds partnerships between public and private interest. Our mining industry initiative, Mining for Habitat, is designed to develop bat habitat conservation and enhancement plans for active mining operations. BCI is helping mining companies and federal and state agencies to conduct bat surveys, protect important bat roosts, and conduct research that will have direct management implications. Inactive underground mines now provide an essential habitat for more than half of North America's 45 bat species, including some of the largest remaining populations and all those listed as endangered. As primary predators of night-flying insects th...
Autumn Migration and Selection of Rock Crevices as Hibernacula by Big Brown Bats in Colorado
Journal of Mammalogy, 2006
Movements, distribution, and roosting requirements of most species of temperate-zone bats in autumn are poorly understood. We conducted the 1st radiotelemetry study of autumn migrations and prehibernation roost selection of bats in western North America. Big brown bats (Eptesicus fuscus, n ΒΌ 55) in the Poudre River watershed, Colorado, moved from low-elevation summer ranges to high-elevation locations in autumn, where they roosted in rock crevices during the period leading up to winter hibernation. We characterized rock crevices used as roosts in autumn at these higher elevations at microhabitat and landscape scales. We used logistic regression combined with an information theoretic approach to determine which variables were most important in roost selection. At the microhabitat scale, autumn roosts were higher to the ground above and below the exit point and were in deeper crevices that had more constant temperatures than randomly selected crevices. At the landscape scale, aspect of the hillside was important, with autumn roosts typically facing north-northwest. Autumn roosts fell into 2 categories: those used for a few days (transient roosts) and those used for !7 days and presumed to be hibernacula. Temperature regimes in the presumed hibernacula appear to provide optimal conditions for use of winter torpor, whereas transient roosts may offer passive rewarming and energy savings for bats still active in early autumn. Elevational segregation of sexes also was documented in our region, with a preponderance of females found at lower elevations and males at higher elevations in summer. Sex ratios at higher elevations became even in autumn. Use of short elevational migrations and selection of hibernation sites in rock crevices may be a common overwintering strategy of insectivorous bats of western North America.