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.

Made available in DSpace on 2014-12-17T15:37:13Z (GMT). No. of bitstreams: 1 MariliaASB_DISSERT.pdf: 1394968 bytes, checksum: b076e332a2c3f4b9375156425fad6f0f (MD5) Previous issue date: 2012-05-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Bats correspond to 20% of the extant mammal species and, with a few exceptions, use echolocation, a spacial orientation system based on emission and analysis of echoes from sound waves, generally ultrasounds. Echolocation was discovered in the 1940 s and since the 1970 s ultrasound detectors have been commercially available, allowing the investigation of several aspects of the natural history and ecology of bats. Passive acoustic monitoring has been frequently used in habitat use studies, predominantly in North America and Europe, by comparing the number of bat passes between different habitat types. This dissertation presents the first evaluation of the spacial and seasonal variation patterns in the activity of insectivorous bats in the Brazilian biome Pampa, in the state of Rio Grande do Sul. Since bat activity can vary according to habitat type, time of year and climatic conditions, the following hypotheses were tested: 1. bat activity varies between different types of habitat; 2. bat activity varies seasonally; 3. bat activity is influenced by temperature, humidity and wind speed. The acoustic samples were taken along fixed transects of 1500 meters, which were monitored monthly from April 2009 to March 2010. Five habitat types were sampled: eucalypts, stream, riparian forest, wetland and grassland. In each sample, the number of bat passes was obtained by using an ultrasound detector Pettersson D230. A total of 1183 bat passes were registered. Greater bat activity levels was observed along large eucalypts (1.93 bat passes/3min) and along a stream (1.61 bat passes/3 min). A riparian forest (0.94 bat passes/3 min) and a wetland area (0.61 bat passes/3 min) exhibited statistically equal levels of activity. Bat passes were fewer in grassland areas (0,16 bat passes/3 min). Bat activity was not correlated with abiotic factors. However, bat activity was significantly low in the colder season, winter, and was similar in autumn, spring and summer. The observed preference for vegetation borders and water courses agrees with reports from other countries and is attributed predominantly to the high prey abundance in these types of environments. Additionally, low activity in the winter is probably a response to the reduced availability of insects, and to lower temperatures. Our results indicate which areas of arboreal vegetation and water courses should be priorities for the conservation of bats and that alterations of these habitat types might negatively influence bat activity in the region / Os morcegos correspondem a 20% dos mam?feros atuais e, com poucas exce??es, apresentam ecolocaliza??o, um sistema de orienta??o espacial a partir da emiss?o e an?lise de ecos de ondas sonoras, geralmente ultrassons. A ecolocaliza??o foi descoberta na d?cada de 1940 e a partir de 1970 detectores de ultrassons tornaram-se comercialmente dispon?veis, permitindo a investiga??o de diversos aspectos sobre hist?ria natural e ecologia de morcegos. Monitoramentos ac?sticos passivos tem sido frequentemente utilizados em estudos de uso de h?bitat, principalmente na Am?rica do Norte e Europa, comparando-se diferentes locais quanto ao n?mero de vezes em que morcegos s?o detectados. A presente disserta??o apresenta a primeira avalia??o de padr?es espaciais e sazonais na atividade de quir?pteros inset?voros do Brasil, realizada no bioma Pampa, Estado do Rio Grande do Sul. Uma vez que a atividade de morcegos pode variar de acordo com o h?bitat, o per?odo do ano e condi??es clim?ticas, foram testadas as seguintes hip?teses: 1. a atividade de morcegos ? heterog?nea entre diferentes tipos de h?bitat; 2. a atividade apresenta varia??es sazonais; 3. a atividade ? influenciada pela temperatura, umidade e velocidade do vento. As amostragens ac?sticas foram realizadas em transectos fixos de 1500 metros, monitorados mensalmente de abril de 2009 a mar?o de 2010. Os transectos abrangeram cinco tipos de h?bitat: Eucaliptos, Mata Ciliar, Banhado, Canal e Campo. Em cada amostragem, foram obtidos o n?mero de registros de atividade com um detector de ultrassons Pettersson D230. No total, foram obtidos 1183 registros de atividade, sendo que os maiores n?veis de atividade de quir?pteros foram observados em ?rea de ?rvores de eucaliptos de grande porte (1,93 registros/3 min) e de um canal (1,61 registros/3 min). Em segundo lugar, a borda de uma mata ciliar (0,94 registros/3 min) e a margem de um banhado (0,61 registros/3 min) apresentaram n?veis estatisticamente equivalentes de atividade. As ?reas de campo foram menos utilizadas. A atividade de quir?pteros n?o apresentou correla??o com os fatores abi?ticos. Por?m, foi significativamente menor na esta??o mais fria, o inverno, e apresentou valores similares no outono, primavera e ver?o. A prefer?ncia por bordas de vegeta??o e cursos d??gua coincide com o documentado para outros pa?ses e ? atribu?da principalmente ? concentra??o de presas nestes tipos de ambiente. Do mesmo modo, a diminui??o da atividade no inverno ? provavelmente uma resposta ? menor disponibilidade de insetos, al?m das baixas temperaturas. Nossos dados indicam que ?reas de vegeta??o arb?rea e cursos d??gua s?o priorit?rias para a conserva??o de morcegos e que altera??es nestes tipos de h?bitat tendem a influenciar negativamente a atividade de morcegos na regi?o