Conneaut Lakeshore, PA, United States
Conneaut Lakeshore, PA, United States

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Miller-Butterworth C.M.,Pennsylvania State University | Vonhof M.J.,Western Michigan University | Rosenstern J.,Pennsylvania State University | Turner G.G.,Pennsylvania Game Commission | Russell A.L.,Grand Valley State University
Journal of Heredity | Year: 2014

Until recently, the little brown bat (Myotis lucifugus) was one of the most common bat species in North America. However, this species currently faces a significant threat from the emerging fungal disease white-nose syndrome (WNS). The aims of this study were to examine the population genetic structure of M. lucifugus hibernating colonies in Pennsylvania (PA) and West Virginia (WV), and to determine whether that population structure may have influenced the pattern of spread of WNS. Samples were obtained from 198 individuals from both uninfected and recently infected colonies located at the crest of the disease front. Both mitochondrial (636bp of cytochrome oxidase I) and nuclear (8 microsatellites) loci were examined. Although no substructure was evident from nuclear DNA, female-mediated gene flow was restricted between hibernacula in western PA and the remaining colonies in eastern and central PA and WV. This mitochondrial genetic structure mirrors topographic variation across the region: 3 hibernating colonies located on the western Appalachian plateau were significantly differentiated from colonies located in the central mountainous and eastern lowland regions, suggesting reduced gene flow between these clusters of colonies. Consistent with the hypothesis that WNS is transmitted primarily through bat-to-bat contact, these same 3 hibernating colonies in westernmost PA remained WNS-free for 1-2 years after the disease had swept through the rest of the state, suggesting that female migration patterns may influence the spread of WNS across the landscape. © 2014 © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.

Robinson K.F.,Cornell University | Diefenbach D.R.,U.S. Geological Survey | Fuller A.K.,Cornell University | Hurst J.E.,NY Environmental Conservation | Rosenberry C.S.,Pennsylvania Game Commission
Journal of Wildlife Management | Year: 2014

Many studies have documented that coyotes (Canis latrans) are the greatest source of natural mortality for white-tailed deer (Odocoileus virginianus) neonates (<3 months old). With the range expansion of coyotes eastward in North America, many stakeholders are concerned that coyote predation may be affecting deer populations adversely. We hypothesized that declines in neonate survival, perhaps caused by increasing coyote predation, could be offset by adjusting or eliminating antlerless harvest allocations. We used a stochastic, age-based population simulation model to evaluate combinations of low neonate survival rates, severe winters, and low adult deer survival rates to determine the effectiveness of reduced antlerless harvest at stabilizing deer populations. We found that even in regions with high winter mortality, reduced antlerless harvest rates could stabilize deer populations with recruitment and survival rates reported in the literature. When neonate survival rates were low (25%) and yearling and adult female survival rates were reduced by 10%, elimination of antlerless harvests failed to stabilize populations. Our results suggest increased deer mortality from coyotes can be addressed through reduced hunting harvest of adult female deer in most circumstances throughout eastern North America. However, specific knowledge of adult female survival rates is important for making management decisions in areas where both neonate and adult survival may be affected by predation and other mortality factors. © 2014 The Wildlife Society.

Silvis A.,Virginia Polytechnic Institute and State University | Ford W.M.,Virginia Polytechnic Institute and State University | Ford W.M.,U.S. Geological Survey | Britzke E.R.,U.S. Army | Johnson J.B.,Pennsylvania Game Commission
Behavioural Processes | Year: 2014

How wildlife social and resource networks are distributed on the landscape and how animals respond to resource loss are important aspects of behavioral ecology. For bats, understanding these responses may improve conservation efforts and provide insights into adaptations to environmental conditions. We tracked maternity colonies of northern bats (Myotis septentrionalis) at Fort Knox, Kentucky, USA to evaluate their social and resource networks and space use. Roost and social network structure differed between maternity colonies. Overall roost availability did not appear to be strongly related to network characteristics or space use. In simulations for our two largest networks, roost removal was related linearly to network fragmentation; despite this, networks were relatively robust, requiring removal of >20% of roosts to cause network fragmentation. Results from our analyses indicate that northern bat behavior and space use may differ among colonies and potentially across the maternity season. Simulation results suggest that colony social structure is robust to fragmentation caused by random loss of small numbers of roosts. Flexible social dynamics and tolerance of roost loss may be adaptive strategies for coping with ephemeral conditions in dynamic forest habitats. © 2014 Elsevier B.V.

Norton A.S.,Pennsylvania State University | Norton A.S.,University of Wisconsin - Madison | Diefenbach D.R.,U.S. Geological Survey | Wallingford B.D.,Pennsylvania Game Commission | Rosenberry C.S.,Pennsylvania Game Commission
Journal of Wildlife Management | Year: 2012

The performance of 2 popular methods that use age-at-harvest data to estimate abundance of white-tailed deer is contingent on assumptions about variation in estimates of subadult (1.5 yr old) and adult (â¥2.5 yr old) male harvest rates. Auxiliary data (e.g., estimates of survival or harvest rates from radiocollared animals) can be used to relax some assumptions, but unless these population parameters exhibit limited temporal or spatial variation, these auxiliary data may not improve accuracy. Unfortunately maintaining sufficient sample sizes of radiocollared deer for parameter estimation in every wildlife management unit (WMU) is not feasible for most state agencies. We monitored the fates of 397 subadult and 225 adult male white-tailed deer across 4 WMUs from 2002 to 2008 using radio telemetry. We investigated spatial and temporal variation in harvest rates and investigated covariates related to the patterns observed. We found that most variation in harvest rates was explained spatially and that adult harvest rates (0.36-0.69) were more variable among study areas than subadult harvest rates (0.26-0.42). We found that hunter effort during the archery and firearms season best explained variation in harvest rates of adult males among WMUs, whereas hunter effort during only the firearms season best explained harvest rates for subadult males. From a population estimation perspective, it is advantageous that most variation was spatial and explained by a readily obtained covariate (hunter effort). However, harvest rates may vary if hunting regulations or hunter behavior change, requiring additional field studies to obtain accurate estimates of harvest rates. © 2011 The Wildlife Society. Copyright © The Wildlife Society, 2011.

Fleegle J.T.,Pennsylvania Game Commission | Rosenberry C.S.,Pennsylvania Game Commission | Wallingford B.D.,Pennsylvania Game Commission
Wildlife Society Bulletin | Year: 2013

Effective deer management must consider diverse stakeholder values. From 2006 to 2011, the Pennsylvania (USA) Game Commission implemented citizen advisory committees (CACs) to measure deer- human conflicts and tolerance for deer populations in each wildlife management unit. There was a general lack of public interest in participating in CACs. Key stakeholder groups were often absent and CACs exhibited a strong hunter bias. Although the CAC process seemed to benefit those involved, the scope was limited and likely did not represent the values and attitudes of the entire citizenry within the wildlife management unit. As a result of this CAC experience, the Pennsylvania Game Commission moved to a citizen survey in 2011 to ensure all interests are represented as the future success of deer management depends on greater understanding of the values and attitudes of every stakeholder. © 2013 The Wildlife Society.

Long E.S.,Pennsylvania State University | Long E.S.,Seattle Pacific University | Diefenbach D.R.,Pennsylvania State University | Wallingford B.D.,Pennsylvania Game Commission | Rosenberry C.S.,Pennsylvania Game Commission
Journal of Wildlife Management | Year: 2010

Natural and anthropogenic landscape features, such as rivers, mountain ranges, and roads can alter animal dispersal paths and movement patterns. Consequently landscape, through its effects on dispersal, may influence many ecological processes, including disease transmission, invasion dynamics, and gene flow. To investigate influences of landscape features on dispersal patterns of a large mammal, we captured and radiomarked 363 juvenile male white-tailed deer (Odocoileus virginianus), including 212 confirmed dispersers, in 2 topographically dissimilar study areas in Pennsylvania, USA. Dispersal azimuths were uniformly distributed in the western study area (WSA), where there was irregular, hilly topography. Mean dispersal azimuths paralleled ridge direction in the eastern study area, where long parallel ridges were aligned northeastsouthwest. Major roads in both areas and a large river in the WSA were semipermeable barriers to dispersal of juvenile males; dispersal paths were less likely to intersect these linear features. Dispersal movements were direct and brief, typically lasting <12 hours. For all dispersers, we found no evidence for preference or avoidance of establishing adult, postdispersal ranges in proximity to roads; however, deer that encountered roads near the terminus of their dispersal path were more likely to stop on the near side. Further, for deer that established postdispersal home ranges near major roads, these features influenced range placement such that locations were typically clustered on one side of the road. The influence of roads, rivers, and mountains on dispersal paths and postdispersal locations of white-tailed deer suggest that landscape-specific features should be considered in conservation and management of this and possibly other species of large mammals. © 2010 The Wildlife Society.

Buderman F.E.,Pennsylvania State University | Diefenbach D.R.,U.S. Geological Survey | Casalena M.J.,Pennsylvania Game Commission | Rosenberry C.S.,Pennsylvania Game Commission | Wallingford B.D.,Pennsylvania Game Commission
Ecology and Evolution | Year: 2014

The Brownie tag-recovery model is useful for estimating harvest rates but assumes all tagged individuals survive to the first hunting season; otherwise, mortality between time of tagging and the hunting season will cause the Brownie estimator to be negatively biased. Alternatively, fitting animals with radio transmitters can be used to accurately estimate harvest rate but may be more costly. We developed a joint model to estimate harvest and annual survival rates that combines known-fate data from animals fitted with transmitters to estimate the probability of surviving the period from capture to the first hunting season, and data from reward-tagged animals in a Brownie tag-recovery model. We evaluated bias and precision of the joint estimator, and how to optimally allocate effort between animals fitted with radio transmitters and inexpensive ear tags or leg bands. Tagging-to-harvest survival rates from >20 individuals with radio transmitters combined with 50-100 reward tags resulted in an unbiased and precise estimator of harvest rates. In addition, the joint model can test whether transmitters affect an individual's probability of being harvested. We illustrate application of the model using data from wild turkey, Meleagris gallapavo, to estimate harvest rates, and data from white-tailed deer, Odocoileus virginianus, to evaluate whether the presence of a visible radio transmitter is related to the probability of a deer being harvested. The joint known-fate tag-recovery model eliminates the requirement to capture and mark animals immediately prior to the hunting season to obtain accurate and precise estimates of harvest rate. In addition, the joint model can assess whether marking animals with radio transmitters affects the individual's probability of being harvested, caused by hunter selectivity or changes in a marked animal's behavior. © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

News Article | December 28, 2016

Wildlife officials in Pennsylvania have identified a common yet highly poisonous shrub as the one that killed a family of bears in a church parking lot earlier this month. Officers from the West Wyoming Police Department received reports of a dead bear cub found at a local parking lot on Dec. 6. When they arrived at the scene, they found four dead bears instead of just one, all of which showed no apparent signs of trauma. The police department said that it considered the death of the bears as suspicious at the time. To find out what could have killed the animals, wildlife officials sent two of the dead bears to the Animal Diagnostic Laboratory at Pennsylvania State University for testing. Following the laboratory tests, officials discovered that the animals were killed not by human interference but by ingesting a poisonous shrub known as an English Yew. The four bears — a bear sow and her three cubs — could have eaten leaves and seeds of the plant, which is known to be very poisonous to humans and animals alike. According to the Pennsylvania Game Commission (PGC), the English Yew (Taxus baccata) is a species of conifer native to Africa, Europe, and southwest Asia. While the plant can grow up to 30 feet in height, it is often pruned into various sizes and configurations. In eastern North America, the English Yew can be found in urban environments, mostly used as an ornamental shrub in gardens. The plant's relatively long life and ability to grow on different soil types make it an ideal choice for topiaries or hedges. The PGC, however, warned that all species of the plant have an alkaloid compound known as taxine, which has been proven to be fatal if ingested. Animals that have single-chambered stomachs are particularly susceptible to the toxin's effects. The game commission believes that the bear sow and her cubs may have been attracted to the yew just when the plant reached its highest toxin levels and no other food sources were available to them at the time. Mark Ternent, a bear biologist for the PGC, explained that black bears often feed the most when they are about to go into hibernation to build their body fat. This would allow them to last all through the winter. It is likely that the bear sow and her cubs were about to enter hibernation, which is why they went out to forage for food. While wildlife officials have encountered bears that have died from unusual causes before, the PGC said this could be the first involving the poisonous shrub. "This unfortunate occurrence was extremely rare and one we hope will not be repeated," Ternent said. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.

News Article | January 19, 2016

Ray's property borders Rothrock State Forest, a prime location for an outdoorsman like himself. Yet when it comes to the apple trees he uses for his annual homemade apple cider, the location poses a bit of a challenge. Those apples are a favorite snack for deer, and he's witnessed firsthand how innocent snacking can ruin any hopes of delicious apple cider. According to Christopher Rosenberry, supervisor of deer and elk management with the Pennsylvania Game Commission, deer snacking like the kind that wipes out Ray's apple harvest is normal behavior, and it presents a danger to the entire forest. "Deer are browsers. They will browse on woody vegetation, and too much browsing may eliminate the small trees in the forest. If there's a timber harvest or an ice storm or something that removes the canopy, and those young trees do not exist under the canopy, you can potentially lose your forest." Thanks to geospatial technologies like GPS, one Penn State research study may soon have a better understanding of how to balance these woodland creatures' affect on forest vegetation. The Deer-Forest Study, led by professors Duane Diefenbach and Marc McDill, is a collaborative project among Penn State, the Pennsylvania Game Commission, the Pennsylvania Department of Conservation and Natural Resources, Bureau of Forestry and the Pennsylvania Cooperative Fish and Wildlife Research Unit. Entering its third year, the study outfits deer in three areas—Rothrock, Bald Eagle and Susquehannock State Forests —with GPS collars that monitor each deer's location. In addition to the GPS collars, field researchers also go in the field to collect data on vegetation levels in the locations visited by each deer. "The objective of the research is to look at the simultaneous effects of deer browsing, competing vegetation and soil conditions on the vegetation that's out there in our forests," said Diefenbach, an adjunct professor of wildlife ecology. According to Diefenbach, the GPS technology has been instrumental in the success of the project. "The deer collar is basically a GPS unit that relies on satellites to estimate a location," Diefenbach said. "Those collars can transmit data to a satellite, which then transfers that information to us via the Internet. Because of this technology, we can get more locations over a longer period of time." Thanks to this technology, Diefenbach, McDill and other researchers can watch remotely from their computers as each deer zigzags across the forest terrain. "I think one thing that the GPS collars have provided is some insights into how adult male deer are able to avoid being killed," Diefenbach said. "Because we've been following their movements every 20 minutes during the hunting season, you can see they respond incredibly quickly to the hunters." According to Diefenbach, opening day of regular deer hunting season in Pennsylvania brings as many as 700,000 hunters to the state's forests. "We've known for decades that adult males are much harder to kill than females or even younger males, but this study has really shed light on how they survive." For a seasoned researcher like Diefenbach, the evolution of technology in the field has been crucial to recent discoveries and advancements in deer research. "When I was a graduate student, we had very high frequency (VHF) collars. Generally, what people did was go out on the ground, try to plot the animal's location as best they could on a USGS topographic map, and then by recording multiple readings of where a signal was coming from so they could determine the location," Diefenbach said. "Using the technology we have today, we can get hundreds of locations per day on one animal. So it's just a game changer in understanding animal movements and how they respond to environmental factors and human activity. There's just no other way we could collect data this accurate." According to Rosenberry, studying deer movements isn't only crucial to species-specific management, it's also necessary for a better understanding of forest management in general. "One of our goals is to maintain deer populations at levels where forest habitat is sustainable. And that's important not only from a deer standpoint—because the forest provides a habitat for deer—but for many other wildlife species, plant species and recreation." For Rosenberry, studying this relationship is an important step in preserving forests for future generations. "When we look at a forest, a lot of times we just see the big trees," Rosenberry said. "But in order for those big trees to exist, there had to be small trees at some point in the past. Those small trees that are growing today will be the forests of tomorrow."

News Article | December 23, 2016

A newly discovered virus infecting the fungus that causes white-nose syndrome in bats could help scientists and wildlife agencies track the spread of the disease that is decimating bat populations in the United States, a new study suggests. Regional variations in this virus could provide clues that would help researchers better understand the epidemiology of white-nose syndrome, according to Marilyn Roossinck, professor of plant pathology and environmental microbiology, College of Agricultural Sciences, Penn State. White-nose syndrome is a particularly lethal wildlife disease, killing an estimated 6 million bats in North America since it was identified in 2006. The disease, caused by the fungus Pseudogymnoascus destructans, first was found in New York and now has spread to 29 states and four Canadian provinces. Although several species of bats have been affected, some of the most prevalent species in the Northeast -- such as little brown bats -- have suffered estimated mortality as high as 99 percent. These losses have serious ecological implications. For instance, bats have a voracious appetite for insects and are credited with helping to control populations of mosquitoes and some agricultural pests. The researchers examined 62 isolates of the fungus, including 35 from the United States, 10 from Canada and 17 from Europe, with the virus infection found only in North American samples. P. destructans is clonal, meaning it is essentially identical everywhere it has been found in North America, making it difficult to determine how it is moving, said Roossinck, who also is affiliated with Penn State's Center for Infectious Disease Dynamics. "But the virus it harbors has quite a bit of variation," she said. "For example, in all the fungal isolates from Pennsylvania we analyzed, the viruses are similar. But those viruses differ from the ones we found in isolates from Canada, New York and so forth." Roossinck explained that fungal viruses are not readily transmitted among fungi, so the variation in the viral genome probably is occurring as the virus evolves within each fungal isolate, providing a marker. "So we believe the differences in the viruses reflect the movement of the fungus, and this viral variability should enable us to get a better handle on how the disease is spreading," she said. The virus is not thought to cause disease, but researchers don't yet know whether it influences the virulence of the fungus, Roossinck noted. "It's very difficult to study virulence in terms of infection in the bats in part because there are almost no bats left to study, and we don't have an experimental system that works." The researchers, who reported their results today (Dec 23) online in PLOS Pathogens, were able to eliminate the virus from one fungal isolate, which provided a virus-free isolate that they could compare to wild isolates that harbor the virus to look for biochemical changes. "Although we didn't look directly at the role of the virus in white-nose syndrome, there is evidence of a close biological relationship between the fungus and the virus," Roossinck said. "We found that the virus-free isolate makes many fewer spores than an isolate with the virus, suggesting that the virus may be beneficial to the fungus in reproduction. "We don't know whether the fungus spreads through spores or through direct contact between bats," she said. "But if it spreads via spores, the virus actually could be enhancing the spread of white-nose syndrome as a result of this increased spore production." Roossinck said the study has important implications in the search for ways to save the bats of North America. "There's a lot we don't know about white-nose syndrome, and before we can develop control strategies, we have to better understand the biology of the system. We now have a tool that can be used in broader studies to examine the epidemiology of the disease." Other Penn State researchers on this project were Vaskar Thapa, postdoctoral fellow in plant pathology and environmental microbiology, and Susan Hafenstein, assistant professor of medicine. Other researchers were Gregory G. Turner, Pennsylvania Game Commission; Barrie E. Overton, biology professor, Lock Haven University of Pennsylvania, and Karen J. Vanderwolf, formerly at New Brunswick Museum, Saint John, Canada, and now at University of Wisconsin, Madison. The Pennsylvania Game Commission, the Huck Institutes of the Life Sciences and the College of Agricultural Sciences, Penn State supported this research.

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