Progress 10/01/16 to 09/30/19
Outputs
Target Audience:The project web page (http://mlitvaitis.unh.edu/Research/BobcatWeb/bobcats.htm) is the main venue for communicating results to the general public. A public talk at the Odiorne Science Center in Rye, NH reached about 60 adults. Data and results generated during the project were being used in two UNH junior/senior-level course on Conservation Genetics and Physiological Ecology, as well as a freshmen course in Environmental Biology. Professional scientists (wildlife biologists,ecologists, zoologists) have been reached via a peer-reviewed article, and statebiologists were updated on the progress of the project during sample collection and pickup. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The work of a PhD student in his final year of study was supported by the project. How have the results been disseminated to communities of interest?A pubic talk, a peer-reviewed manuscript, our project web page, and updated news releases of the project by the UNH AES were the main forms of dissemination of our results. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
With an increase in urbanization and development of the landscape, increased interactions (sightings, conflict, injury) between wildlife and humans are reported; and although the public often responds enthusiastically, the potential for property damage, injury and loss of domestic animals, and risk of disease transmission also exist. Adjustment to urban conditions by wild animals requires a suite of physiological and behavioral adaptations referred to as synurbization. The project tested proxies of synurbization (i.e., dietary shifts, levels of stress hormone in hair) against the population genetic structure of bobcats in northern New England so as to increase our understanding of bobcat distributions, especially relative to human landscape use. The results can be used to develop recommendations for effective management strategies that balance the interests of different stakeholder groups. Our results for each objective were as follows: Objective 1: Identify diet shifts associated with increased synurbization using isotope signatures. Results: An analysis of carbon and nitrogen isotope ratios of 154 contemporary and 122 historic bobcat samples and their putative prey species revealed that historically bobcats fed mostly on rabbits and snowshoe hares (lagomorphs). Today's bobcats have switched prey to mostly small mammals, especially squirrels. This prey switch most likely is due to habitat changes. A marked increase in human population resulted in more suburban and exurban tracts that encroach on what formerly was continuous wildland habitat. Consequently, bobcats may experience increased opportunities to prey on a variety of small mammals common in such areas. Our results do not support turkeys as a major component of bobcat diets despite the dramatic resurgence of turkeys in New England. Objective 2: Quantify and compare levels of a stress hormone (cortisol) in rural vs. synurbic bobcats. Results: Cortisol levels were measured in 124 samples of bobcat hair collected from New Hampshire and Vermont, and from three captive individuals. Females had consistently higher hair cortisol concentrations (HCC) than males. Overall individuals living in areas of high agricultural use and open development had higher HCC. However, development associated with human housing corresponded with lower HCC values. This suggests that bobcats habituate to human presence and may even select for it due to the availability of anthropogenic resources (e.g., backyard bird feeders visited by squirrels). Objective 3: Further refine an existing population genetic structure model of bobcats and determine any correlations with results from objectives 1 and 2. Results: The population genetic structure model was completed in year 2 and was published in a peer-reviewed journal. An integration of the results from objectives 1 and 2 with the model revealed differences in diets among genetic subpopulations, a reflection of significant differences in landscape. Furthermore, trophic dynamics have direct impacts on stress hormone levels of populations by altering the ease of access to resources, or indirectly via competitive interactions. Increased HCC were found with higher proportion of squirrels in the bobcat diet, whereas lower HCC were measured in bobcats feeding on large mammals (e.g., white-tail deer, porcupines). This suggests large mammals may be a more profitable prey species for bobcats than smaller-bodied prey such as squirrels. Thus, more profitable prey species explain the negative association between HCC and large mammals, whereas smaller prey, like squirrels drive the positive association with HCC. Objective 4: Public and educational outreach. Results: see section on dissemination of results and target audience.
Publications
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2019
Citation:
Carroll, RP. 2019. Direct and indirect effects of anthropogenic land use on bobcats (Lybx Rufus) in New England. PhD Dissertation, University of New Hampshire, Durham, NH.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Carroll RP, Litvaitis MK, Clements SJ, Stevens CL, Litvaitis JL. History matters: Contemporary vs. historic population structure of bobcats in the New England region, USA. Conservation Genetics 20: 743-757
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience: The project web page (http://mlitvaitis.unh.edu/Research/BobcatWeb/genetics.htm) is the main venue for communicating results to the general public. Hands-on presentations to elementary school students on bobcats and wildlife continue, as well as public talks and presentations at the NH Farm and Forest Expo and the New Boston Farmers Market. Data and results generated during the project are also being used in two UNH junior/senior-level course on Conservation Genetics and Physiological Ecology, as well as a freshmen course in Environmental Biology. Professional scientists (wildlife biologists, ecologists, zoologists) have been reached via a presentation at a national meeting of the Wildlife Society. State wildlife biologists are updated on the progress of the project during sample collection and pickup. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The workof a PhD student in his final year of studycontinues to be supported by the project. How have the results been disseminated to communities of interest? Pubic talks and presentations, a presentation at a scientific conference, a peer-reviewed manuscript, our project web page, and updated news releases of the project by the UNH AES. What do you plan to do during the next reporting period to accomplish the goals?1. We will examine isotope ratios in a few additonal prey items to further refine the isotope comonent of the project. 2. Cortisol quantification and data analysis will be the major focus of the next reporting period. 3. We will continue to provide formal and informal presentations on the project to any group requesting them.
Impacts
What was accomplished under these goals?
This project aims to identify recent dietary shifts andlevels of stress hormone in hairof New England bobcats. This will lead to a more comprehensive understanding of bobcat distributions in the region, especially relative to human landscape use. The results will impact management strategies, allowinga moreeffectivebalancingofinterests of different stakeholders. 1. We have largely completed our data collection and analysis of bobcat trophic ecology using stable isotopes. We found that carbon and nitrogen isotopes in bobcat hair are on average higher than in the diet (2.339‰and 3.596 ‰, respectively). Comparisons between historic (1952-1964) and contemporary (2008-2017) samples revealed that contemporary bobcats have significantly larger carbon isotope values and occupy a three-times-larger trophic niche. This is an indication of human-facilitated subsidies to the bobcat diet, especially corn. We also classified 32 potential bobcat prey species into seven isotopically-distinct diet guilds. This allowed us to identify a diet shift from a historic diet that was very heavy in rabbit and snowshoe hare based to a new diet consisting of rabbits and squirrels. Our results do not support turkeys as a major component of bobcat diets despite the dramatic resurgence of turkeys in New England. 2. We continued to assay bobcat hair samples to quantify individual cortisol levels. As is standard in studies using ELISA assays, we have validated our assay through repeated quantification of samples and we determined intra- and inter-assay variation. Further analysis, including incorporating whether there is a link between diet and stress, is expected in the coming months. 3. Our population genetic model has been completed and the results were submitted for publication to the peer-reviewed journal Conservation Genetics. The manuscript has been accepted, pending revisions which were returned on Nov 12, 2018. We found population substructure in bobcats across New England. Some subdivisions correspond to anthropogenic barriers (e.g., interstate highways). Correlations with isotope analyses from objective 1 reveal that some population structuring is a result of behavioral dynamics based on diet preferences, especially in areas of agriculture.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Carroll RP, Litvaitis MK, Hobbie EA. 2018. Setting the table: Large-scale human influence on the diet of a charismatic mesopredator, the bobcat (Lynx rufus). Annual meeting of the Wildlife Society, Cleveland, OH, October 2018.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience: The project web page (http://mlitvaitis.unh.edu/Research/BobcatWeb/genetics.htm) is the main venue for communicating results to the general public. It is continually expanded and updated. Hands-on presentations to middle and high school students on bobcats and wildlife continue, as well as public talks. Data and results generated during the project are also being used in a UNH junior/senior-level course on Conservation Genetics. Professional scientists (wildlife biologists, ecologists, zoologists) have been reached via a peer-reviewed publication, and a regional and an international presentation. State wildlife biologists are updated on the progress of the project during sample collection and pickup. Changes/Problems:Currently, we are facing a delay for receiving our isotope data from the UNH Isotope facility. What opportunities for training and professional development has the project provided?Two undergraduates have worked in the lab as paid interns on the project. One PhD student is also being trained. How have the results been disseminated to communities of interest?Through public talks, a presentation at a scientific conference, a peer-reviewed manuscript, our project web page, and interviews with the media. In addition, the news release of the project has been picked up by more than 40 national and international media outlets. What do you plan to do during the next reporting period to accomplish the goals?1. We plan to analyze data from our submitted isotope samples. This will allow us to refine our sampling approach. 2. Hair collection for cortisol quantification will continue. We have contacted an additional facility (Buttonwood Zoo, New Bedford, MA) that holds captive bobcats and will be receiving samples before the end of the year. 3. Final analyses of the genetic component are in progress and a manuscript will be submitted during the next reporting period. 4. We will continue to provide formal and informal presentations on the project to any group requesting them.
Impacts
What was accomplished under these goals?
With an increase in urbanization and development of the landscape, increased interactions (sightings, conflict, injury) between wildlife and humans are reported.Adjustment to urban conditions by wild animals requires a suite of physiological and behavioral adaptations referred to as synurbization.Thisproject will test proxies of synurbization (i.e., dietary shifts, levels of stress hormone in hair) against the population genetic structure of bobcats in northern New England to contribute to a more comprehensive understanding of their distributions, especially relative to human landscape use.The results can be used to develop recommendations for effective management strategies that balance interests of different stakeholder groups. 1. We have collected and processed 326 bobcat and 260 prey samples. Thus far 522 samples have been submitted to the UNH Stable Isotope Lab for isotopic analysis of carbon, nitrogen, and sulfur. We are awaiting the results from the facility. Bobcat samples come from New Hampshire, Vermont, Maine, and Texas. Texas bobcats are included because they come from a very urbanized population (Dallas-Fort Worth) and can serve as a standard for urbanized isotopic values. Bobcat samples vary in their sampling period and tissue type (hair vs. bone), to allow for recognition of long- and short-term trophic trends. We also have collected samples from captive bobcats (n = 12) and their known diets (n = 5) to calibrate our models of prey species importance. 2. Hair samples of 187 bobcats, including 99 males and 88 females, have been collected and their cortisol concentrations have been quantified. Additionally, 11 samples from captive bobcats to serve as controls have also been analysed. Preliminary analyses reveal a positive correlation between development and levels of the stress hormone cortisol at multiple scales. At the town scale, low intensity development such as suburban or exurban areas corresponded to higher cortisol levels in synurbic bobcats. At the much larger Wildlife Management Unit scale, a high density of roads was the greatest predictor of stress hormone levels. 3. We have added 63 bobcats (NH, n = 20; VT, n = 43) to our sample population in the past year, collecting tissue for genetic analysis, hair for cortisol analysis, and hair and bone for stable isotope analyses. All samples have been genotyped with 13 molecular markers and are being included in future population genetic analyses. 4. We have provided 3 area schools with show-and-tell demonstrations of the project and with general activities regarding carniovore ecology. We also have provided lab activities for a college-level course in "Inventory and Monitoring" for Widllife and Conservation Biology majors. Finally, we gave a public presentation about the importance of biodiversity conservation to about 150 attendees of the Green Mountain Conservation Group, and presented our results at a scientific conference.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Reed GC, Litvaitis JA, Callahan C, Carroll RP, Litvaitis MK, Broman DJA. 2017. Modeling landscape connectivity for bobcats using expert opinion, and empirically-derived models: how well do they work? Animal Conservation 20: 308-320
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2017
Citation:
Carroll RP, Litvaitis MK, Litvaitis JA, Foxall TL. 2017. Stress in the city: Influence of landscape-scale development on chronic stress levels in bobcats. Northeast Natural History Conference, Cromwell, CT.
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