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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Detection and modeling of bat species occupancy at multiple scales across a forested landscape in southeastern Missouri

Yates, Mark D., January 2006 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 14, 2007) Vita. Includes bibliographical references.
12

Day-roosting Social Ecology of the Northern Long-eared Bat (Myotis septentrionalis) and the Endangered Indiana Bat (Myotis sodalis)

Silvis, Alexander 08 December 2014 (has links)
Day-roost use by northern long-eared bat (Myotis septentrionalis) maternity colonies on the Fort Knox military reservation, Kentucky, USA, resulted in formation of non-random networks of roosts that exhibited a trend toward centralization. Centralization of day-roost networks was reflected in the social structure of colonies, which were characterized by dense associations among individuals within colonies. Social structure varied among colonies and appeared to be related to reproductive condition; colonies exhibited greater cohesiveness during parturition and lactation. Northern long-eared bat maternity colonies appeared to be exclusive, occupying distinct roosting areas with one or several areas receiving intense use. Day-roost removal simulations suggested a linear relationship between colony fragmentation and roost loss, and that loss of >20% of roosts is required to initiate colony fragmentation. Experimental hierarchical removal of day-roosts yielded results consistent with simulations, as removal of the single most-central (primary) roost had no impact on colony fragmentation, whereas removal of 24% of less-central (secondary) roosts resulted in partial network fragmentation. Patterns of colony day-roost and space use were similar pre- and post-removal treatments. Day-roost removal did not alter the number of roosts used by individual bats, but distances moved between roosts were greater in the secondary roost-removal treatment group. Day-roost characteristics largely were consistent pre-post treatment for both treatment groups. Historical data from an Indiana bat (Myotis sodalis) maternity colony revealed that this species also exhibits a non-random social assorting dynamic. Non-random social assortment resulted in a closely connected centralized network of day-roosts. Individuals within the Indiana bat maternity colony exhibited close social connections with colony members, but subgroups likely existed within the colony. Indiana bat day-roosting ecology appears flexible, as patterns of roost and space use differed substantially between years. Development of specific, but tactical, management approaches for individual colonies of both northern long-eared and Indiana bats may be possible. Such approaches would allow land managers to manage for both northern long-eared bat habitat and other objectives. However, the nature of targeted management approaches employed likely will depend on the unique forest context and dynamic within which individual colonies reside. / Ph. D.
13

Assessing the Long-term Impacts of White-nose Syndrome on Bat Communities Using Acoustic Surveys at Fort Drum Military Installation

Nocera, Tomas 12 June 2018 (has links)
With declines in abundance and changing distribution of White-nose Syndrome (WNS)-affected bat species, increased reliance on acoustic monitoring is now the new "normal". As such, the ability to accurately identify individual bat species with acoustic identification programs has become increasingly important. Additionally, how bat distribution and habitat associations have changed at the local to sub-landscape scale in the post WNS environment is important to understand. The significance of these changes, relative to bat activity, may be based on the species-specific susceptibility to WNS. We used data collected from Fort Drum Military Installation, New York from the summers of 2003-2017 to analyze the accuracy of acoustic software programs, and assess the changes in relative bat activity, occupancy, and distribution induced by WNS. Our results indicate that continued acoustic monitoring of bat species, such as the little brown bat (Myotis lucifugus) in the Northeast, to assess ongoing temporal and spatial changes, habitat associations, and as a guide to direct future mist-netting should rely more on relative activity as the metric of choice. Furthermore, the continuous spread of WNS across North America will have strong negative effects on bat populations and communities, this study points to how individual species (both impacted and non-impacted) will respond to WNS. We believe that our results can help users choose automated software and MLE thresholds more appropriate for their needs to accurately address potential changes in communities of bat species due to impacts of WNS or other factors. / MS
14

Acoustic sampling considerations for bats in the post-white-nose syndrome landscape

Barr, Elaine Lewis 27 January 2020 (has links)
Bat populations across North America are either facing new threats from white-nose syndrome (WNS) and wind energy development or have already experienced precipitous declines. Accordingly, researchers and managers need to know how to best monitor bats to document population and distribution changes, as well as where to look for persisting populations. Landscape-scale WNS impacts to summer bat populations are not well understood, and although acoustic monitoring is commonly used to monitor these populations, there is limited information about differences among acoustic detectors and the implications to managers thereof. My objectives were to model the relationship between WNS impact, influence of available hibernacula, and environmental factors for summer nightly presence of three WNS-affected bats and to compare how multiple models of acoustic detectors perform in terms of detection probability and nightly recorded bat activity. I collected acoustic data from 10 study areas across Virginia, West Virginia, Ohio and Kentucky to describe changes in nightly presence of WNS-affected bat species during summer 2017. During the same period of time, I compared five types of acoustic detectors at Fort Knox, Kentucky. My results show the potential efficacy of using a WNS impact-year metric to predict summer bat presence, and highlight which environmental variables are relevant for large-scale acoustic monitoring. Additionally, my findings suggest that each of the detector types tested would suffice for most research and monitoring activities, but standardization of detector type within the scope of a project or study should be encouraged. / Master of Science / Bat populations across North America are either facing new threats from white-nose syndrome (WNS) and wind energy development or have already experienced devastating declines. Accordingly, wildlife biologists need to know how to best monitor bats to document population and distribution changes, as well as where to look for remaining populations. Landscape-scale WNS impacts to summer bat populations are not well understood, and although acoustic technology is commonly used to monitor these populations, there is limited information about differences among acoustic detectors and the implications to managers thereof. My objectives were to model the relationship between WNS impact, influence of available bat hibernation caves, and environmental factors for summer nightly presence of three WNS-affected bats and to compare how multiple models of acoustic detectors perform in terms of detection probability and nightly recorded bat activity. I collected acoustic data from 10 study areas across Virginia, West Virginia, Ohio and Kentucky to describe changes in nightly presence of WNS-affected bat species during summer 2017. During the same period of time, I compared five types of acoustic detectors at Fort Knox, Kentucky. My results show potential viability of a WNS impact-year metric to predict summer bat presence, and highlight which environmental variables are relevant for large-scale acoustic monitoring. Additionally, my findings suggest that each of the detector types tested would suit most research and monitoring activities, but standardization of detector type within the scope of a project or study should be encouraged.
15

Determining energy conservation during torpor for three Myotis species and response of Myotis species to human disturbance while day roosting

Sichmeller, Timothy J. January 2010 (has links)
The endangered Indiana bat (Myotis sodalis) has been the focus of much research in the past 40 years, primarily with respect to the summer habitat requirements for the species. Recent advances in radio telemetry have allowed researchers to learn about the specific activity patterns for roosting bats. Torpor is an energetic process that bats use to conserve energy through the day. We used an equation that gives a threshold for when the animal enters torpor to quantify the amount of energy conservation among Indiana bats, northern long-eared bat (M. septentrionalis) and little brown bat (M. lucifugus) and their reproductive stage. Additionally, we used the torpor threshold to determine if researchers were causing disturbances to roosting female Myotis bats in the summer. / Department of Biology

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