Mianus River Gorge Preserve

Bedford, NY, United States

Mianus River Gorge Preserve

Bedford, NY, United States
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Weckel M.E.,Mianus River Gorge Preserve | Weckel M.E.,American Museum of Natural History | MacK D.,Mianus River Gorge Preserve | Nagy C.,Mianus River Gorge Preserve | And 3 more authors.
Journal of Wildlife Management | Year: 2010

The expansion of coyotes (Canis latrans) into the northeastern United States is a major challenge to wildlife professionals, especially in suburban and urban areas where reports of humancoyote interaction (HCI) are on the rise. To assist wildlife professionals in identifying potential hot spots of interaction and homeowners in evaluating their risk of a backyard encounter, we used the techniques of citizen science to build a landscape model of HCI for suburban residential properties in Westchester County, New York, USA. We distributed surveys via school children (kindergarten to grade 12) as part of a voluntary class assignment, to maximize the number of homeowners participating in our study and to provide learning experiences for students. Of 6,000 surveys distributed to schools, >1,500 students interviewed their parents on whether a coyote had been seen or heard on their property from 2003 to 2006. Although surveys could not be distributed randomly owing to the participatory process of individual schools, we did receive responses from across Westchester County, representing the spectrum from the most rural to the most urban towns. Homeowners who encountered (i.e., seen or heard) a coyote on their property were on average 50 closer to forest, 36 closer to grassland, and 66 farther from medium-to high-intensity development, complementing existing knowledge on urban coyote habitat use. Our model seemed robust in predicting an independent set of coyote observations (r 0.88). Based on this model, we generated a map describing the probability of HCI that can be used by both wildlife professionals and homeowners. Regarding the former, state wildlife agencies could more precisely target education campaigns on how to live with coyotes where the possibility of HCI was greatest. Homeowners, in turn, could evaluate their own risk and modify behaviors that would make their property less attractive to coyotes. Furthermore, in creating a descriptive model of HCI from citizen-generated data, we demonstrated how citizen science can be a useful exploratory tool, generating a wealth of data over a large geographic area in a short period, especially when the inquest is appropriate to stakeholder participation in data collection. © 2010 The Wildlife Society.

Nagy C.,Mianus River Gorge Preserve | Nagy C.,American Museum of Natural History | Nagy C.,City University of New York | Bardwell K.,Mianus River Gorge Preserve | And 5 more authors.
Northeastern Naturalist | Year: 2012

We characterized the landscape-level habitat use of Megascops asio (Eastern Screech Owl) in a suburban/urban region of New York and Connecticut using citizen-science methodologies and GIS-based land-use information. Volunteers sampled their properties using call-playback surveys in the summers of 2009 and 2010. We modeled detection and occupancy as functions of distance to forest and two coarse measures of development. AIC c-supported models were validated with an independent dataset collected by trained professionals. Validated models indicated a negative association between occupancy and percent forest cover or, similarly, a positive association with percent impervious cover. When compared against the systematic dataset, models that used forest cover as a predictor had the highest accuracy (kappa = 0.73 ± 0.18) in predicting the occupancy observations in the systematic survey. After accounting for detection, both datasets support similar owl-habitat patterns of predicting occupancy in developed areas compared to highly rural. While there is likely a minimum amount of forest cover and/or maximum level of urbanization that Screech Owls can tolerate, such limits appear to be beyond the ranges sampled in this study. Future research that seeks to determine this development limit should focus on very urbanized areas. The high accuracy of the citizen-science models in predicting the systematic dataset indicates that volunteer-based efforts can provide reliable data for wildlife studies.

Weckel M.,Mianus River Gorge Preserve | Weckel M.,American Museum of Natural History | Weckel M.,City University of New York | Rockwell R.F.,American Museum of Natural History | Secret F.,John Jay High School
Wildlife Society Bulletin | Year: 2011

Jacobson et al.'s (1997) individual branch-antlered male (IBAM) method is a popular camera technique for estimating white-tailed deer (Odocoileus virginianus) abundance. Demographic ratios are estimated from raw photographic occurrences (RPO) of males, females, and fawns. Point abundance estimates of each group are estimated by using said ratios to extrapolate from a count of uniquely identifiable males. In 2009, using camera-trap data from the Mianus River Gorge Preserve (NY), we modified the IBAM technique to 1) generate measures of uncertainty for parameter estimates via bootstrapping camera stations, and 2) address the concern that RPO ratios may be biased if groups of animals differ in their probability of being photographed (e.g., trap success [TS]). For each sex-age group, we evaluated RPO as a function of TS using linear regression to generate photographic counts standardized by TS (standardized photographic occurrences [SPO]). We generated estimates of sex-age ratios and abundances using both RPO and SPO. To evaluate the accuracy of using SPO in conjunction with the IBAM method, we independently estimated the abundance of a marked group of female deer using a Poisson log normal (PNE) mark-resight estimator. Abundance estimates across sex-age classes were most similar between PNE and IBAM when SPO demographic ratios were used. Owing to the greater TS of females, using SPO discounted the relative abundance of females and, thus, lowered the female:male ratios and raised the fawn:female ratio. Uncertainty was broad across all approaches, yet accounting for TS reduced the confounding variability owing to differences in detection probability and generated more accurate parameter estimates. © 2011 The Wildlife Society.

Nagy C.M.,Mianus River Gorge Preserve | Nagy C.M.,American Museum of Natural History | Weckel M.E.,Mianus River Gorge Preserve | Weckel M.E.,American Museum of Natural History | And 3 more authors.
Wildlife Biology in Practice | Year: 2012

We evaluated the accuracy of a previously published model of coyote (Canis latrans) sightings in suburban Westchester County, New York. This model was originally developed using citizen reports of coyote sightings to predict the probability of a human-coyote interaction based on proximity to habitat features. Because the data were obtained from surveys, researchers could not separate patterns of site occupancy by coyotes from possible patterns of detection by respondents. Nevertheless, the model could be an indicator of site occupancy within the suburban matrix. We sought to evaluate the predictive power of the human-coyote interaction model with data gathered via a more rigorous method. To build a set of validation sites, we surveyed 11 parks in Westchester County and one park in Bronx County, NY with camera traps between April and October of 2010. The probability of photographing a coyote in a single trap-night was 0.06 ± 0.12 and all sites had >0.9 probability of detecting a coyote at least once given the total trap-nights at each site. During validation, we also added four additional sites that had been surveyed by other researchers with camera traps as additional "present" sites. Predictions of coyote presence or absence based on the human-coyote interaction model for these 16 validation sites were compared to the observed survey results. The model, which contained distances to forest, grassland, and pooled medium and high development performed well in predicting the observed data (kappa = 0.75 ± 0.17, Area-Under-Curve of Receiver-Operator-Characteristic plots = 0.90). The model appears to sufficiently predict coyote occupancy in a suburban-urban landscape and will form the basis of for development of a more comprehensive model of coyote distribution in the New York City metropolitan area. Furthermore, its accuracy illustrates how citizen science can provide reliable estimates of wildlife-habitat patterns in urban areas. © 2012 C.M. Nagy; M.E. Weckel; A. Toomey; C.E. Burns; J. Peltz.

Nagy C.,Mianus River Gorge Preserve | Nagy C.,American Museum of Natural History | Aschen S.,Mianus River Gorge Preserve | Christie R.,Mianus River Gorge Preserve | And 2 more authors.
Urban Habitats | Year: 2011

Japanese stilt grass (Microstegium vimineum) is an invasive grass in the eastern and midwestern United States. It tolerates a wide range of light and moisture conditions and has readily replaced native herbaceous vegetation in many areas. Despite its detrimental effects, Japanese stilt grass does provide some benefit, serving as habitat for ground amphibians such as frogs and toads (anurans) in areas where populations of white-tailed deer (Odocoileus virginianus) have depleted native herbaceous cover. We investigated relative abundances of common anuran species both inside and outside of a stilt grass invasion front in a Northeastern mixed hardwood forest. We used pitfall trap arrays to sample anuran species during the summers of 2006 and 2007 and we captured four species: wood frog (Rana sylvatica); pickerel frog (Lithobates palustris); spring peeper (Pseudacris crucifer); and American toad (Bufo americanus). We captured more individuals from each of these species in stilt grass plots. Too few spring peepers were captured for analysis, so we modeled the captures of the three remaining species-wood frog, pickerel frog, and American toad-with negative binomial regression against stilt grass presence/absence, soil moisture, soil temperature, and relative humidity. We compared models containing these parameters using AIC (Akaike's Information Criterion), a common information criterion used in model selection. All three species selected stilt grass plots, but appeared to do so for different reasons. Pickerel and wood frogs seemed to select primarily areas of high soil moisture, which was consistently greater in stilt grass plots. American toads selected stilt grass areas and areas of high humidity, though humidity did not vary according to stilt grass presence or absence. For all three species, stilt grass seemed to provide habitat value beyond any causal or correlative relationship with microclimate. These results suggest that some invasive species of herbaceous cover provide alternative habitat for native wildlife in degraded communities. Managers need to consider the effect on wildlife when considering removal of invasives, particularly when there is little native habitat and when removal would be destructive.

Weckel M.,Mianus River Gorge Preserve | Weckel M.,American Museum of Natural History | Weckel M.,City University of New York | Rockwell R.F.,American Museum of Natural History | Wincorn A.,Mianus River Gorge Preserve
Wildlife Society Bulletin | Year: 2011

Over the last decade, wildlife professionals in the New York City (NY, USA) metropolitan area have increasingly turned to controlled archery hunts to reduce overabundant suburban deer populations. The success of these deer management programs (DMPs) depends on a willing pool of hunters motivated to meet harvest goals. This requires maintaining hunter satisfaction both now, and in the future when successful herd reduction will result in fewer opportunities for deer harvest. With the goal of providing local deer managers with feedback from hunters partaking in DMPs, we used surveys designed to evaluate why members hunted, why they joined DMPs, members' views on deer management, and ultimately, their satisfaction with controlled hunts. Members were primarily motivated to hunt by the chance to see wildlife, opportunities for recreation, and a passion for archery. Most (71%) reported that their enjoyment had increased since first joining a DMP and satisfaction was not linked to harvest opportunity or success. Nevertheless, we documented several trends that threaten the long-term sustainability of DMPs. First, 78.2% of survey respondents were over the age of 40, possibly suggesting fewer younger recruits into DMPs. Second, the opportunity to hunt previously unhunted land, a transitory incentive, was the most common reason for participating in DMPs. Third, respondents whose DMP doe harvest was limited by choosing to spend time on private, non-DMP land were also more likely to have seen fewer deer on DMP lands (G-test = 13.2, df = 4, P = 0.01). This suggests that effort will decline as deer herds decline. © 2011 The Wildlife Society.

Severe fragmentation is a typical fate of native remnant habitats in cities, and urban wildlife with limited dispersal ability are predicted to lose genetic variation in isolated urban patches. However, little information exists on the characteristics of urban green spaces required to conserve genetic variation. In this study, we examine whether isolation in New York City (NYC) parks results in genetic bottlenecks in white-footed mice (Peromyscus leucopus), and test the hypotheses that park size and time since isolation are associated with genetic variability using nonlinear regression and information-theoretic model selection.White-footed mice have previously been documented to exhibit male-biased dispersal, which may create disparities in genetic variation between males and females in urban parks.We use genotypes of 18 neutral microsatellite data and four different statistical tests to assess this prediction. Given that sex-biased dispersal may create disparities between population genetic patterns inferred from bi- vs. uni-parentally inherited markers, we also sequenced a 324 bp segment of the mitochondrial D-loop for independent inferences of historical demography in urban P. leucopus. We report that isolation in urban parks does not necessarily result in genetic bottlenecks; only three out of 14 populations in NYC parks exhibited a signature of a recent bottleneck at 18 neutral microsatellite loci. Mouse populations in larger urban parks, or parks that have been isolated for shorter periods of time, also do not generally contain greater genetic variation than populations in smaller parks. These results suggest that even small networks of green spaces may be sufficient to maintain the evolutionary potential of native species with certain characteristics. We also found that isolation in urban parks results in weak to nonexistent sex-biased dispersal in a species known to exhibit male-biased dispersal in less fragmented environments. In contrast to nuclear loci, mitochondrial D-loop haplotypes exhibited amutational pattern of demographic expansion after a recent bottleneck or selective sweep. Estimates of the timing of this expansion suggest that it occurred concurrent with urbanization of NYC over the last few dozens to hundreds of years. Given the general non-neutrality of mtDNA in many systems and evidence of selection on related coding sequences in urban P. leucopus, we argue that the P. leucopus mitochondrial genome experienced recent negative selection against haplotypes not favored in isolated urban parks. In general, rapid adaptive evolution driven by urbanization, global climate change, and other human-caused factors is underappreciated by evolutionary biologists, but many more cases will likely be documented in the near future. © 2014 Munshi-South and Nagy.

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