Conservation and Ecology of Mammals – Ursids

Contributed Paper
ROOM: Room 130 – Cimarron
SESSION NUMBER: 37
 

10:30AM Population Dynamics and Harvest Sustainability of Two Small, Reintroduced American Black Bear Populations
Sean M. Murphy; John J. Cox; Ben C. Augustine; John T. Hast; Joseph M. Guthrie; Jayson H. Plaxico; Sutton C. Maehr; Michael Strunk; Tristan M. Curry
ABSTRACT During the 1990s, two American black bear (Ursus americanus) reintroductions using small founder groups occurred along the Kentucky-Virginia and Kentucky-Tennessee borders in the Central Appalachians, USA, which established 2 relatively small, allopatric populations by 2012 (N = 482 and 228 bears, respectively). Late autumn (Nov.–Dec.) legal harvests were implemented in both populations by 2013 and harvest limits have annually increased since. An early autumn (Sept.–Oct.) harvest was subsequently added during 2015–2016, which could result in increased female bear mortality and thus, threaten reintroduction success. We captured and radio-monitored 91 (36M:55F) total bears during 2010–2016 to estimate population vital rates, and used individual-based population models to evaluate short-term reintroduction success, population viability, and harvest sustainability. Adult female annual survival was high (S = 0.93–0.99) and litter sizes were average (mean = 2.17–2.39 cubs) relative to most other hunted black bear populations. All mortality was anthropogenic; legal harvest and agency euthanasia of conflict bears were the most probable causes of mortality (P = 0.28–0.33). Average annual population growth rates were moderate in both populations (λ = 1.07–1.08/year) when only late autumn harvests occurred. However, the addition of early autumn harvests resulted in a high probability of ≥ 25% population decline within 10 years in the smallest population (P = 0.91) and stabilized the largest population (λ = 1.00/year). Although our findings demonstrate short-term reintroduction success was obtained in both populations, early autumn harvests could cause a precipitous decline in the smaller, isolated population as a consequence of increased female bear mortality. We suggest managers consider temporarily discontinuing early autumn harvests and re-implementing annual vital rate monitoring to detect responses to management changes in these relatively small, reintroduced populations.
10:50AM Understanding Motivations for Human Behaviors to Limit Human-Wildlife Conflict
Stacy Lischka; Tara Teel; Heather Johnson; Courtney Larson; Stewart Breck; Kevin Crooks
Regulations are often viewed as an effective way to motivate human behaviors to address human-wildlife conflicts. In response to increases in human-black bear conflicts in North America, many communities have instituted ordinances requiring bear-proofing of residential garbage. Compliance with these ordinances varies within and across communities, leading to varying success at reducing conflict. Human dimensions research can play an important role in improving compliance by providing information about residents’ motivations for keeping garbage secured, as well as characteristics of individuals who comply. To this end, we observed bear-proofing behavior at a sample of 240 households in 2014 and 2016, in conjunction with a community-wide bear-proofing experiment in Durango, Colorado. We used mail-back surveys and observations of human-bear conflicts to assess drivers of compliance behavior. We found that most residents used bear-resistant containers irregularly, at best; only 20% of observed households were compliant on all observations in 2014 and 26% in 2016. Garbage-related conflicts with bears were common, with residents experiencing an average of 2.6 conflicts/parcel in 2013 and 1.33 conflicts/parcel in 2015. Regression models of compliance behavior showed that experience of garbage-related conflicts with bears increased compliance and higher trust in the management agency decreased compliance behavior. Social norms regarding bear-proofing, benefits and risks associated with bears, values toward wildlife, perceptions of personal control over human-bear conflict and demographics were not important predictors of compliance. These findings indicate that rates of voluntary compliance will fluctuate with annual changes in natural food availability and conflict, and are likely to be highest in areas where residents perceive the highest risks associated with black bears. This information will allow managers and practitioners to design targeted behavior change campaigns that can account for factors which motivate voluntary compliance, and supplement those efforts with the minimal amount of enforcement required to achieve desired results.
11:10AM Compounding Effects of a Natural Food Shortage and Human Development on a Large Carnivore Population Along a Human Development-Wildland Interface
Jared Laufenberg; Heather Johnson; Paul Doherty; Stewart Breck
Climate change and human development are two stressors that threaten numerous wildlife populations, and recent research suggesting that the combined effects of multiple stressors are likely to be particularly detrimental to populations. Such effects are likely to be pronounced along the human developement-wildland interface, where changes in both natural and anthropogenic conditions interact to affect wildlife populations. To better understand the compounding influence of these stressors on a natural population, we investigated the effects of a climate-induced natural food shortage on the dynamics of a American black bear (Ursus americanus) population that surrounded the city of Durango, located in southwest Colorado. We integrated 4 years (2 years pre- and 2 years post-food shortage) of DNA-based capture-mark-recapture data with GPS-based telemetry data to evaluate the effects of a food shortage on the abundance, density and spatial distribution of female black bears living adjacent to human development. We documented a 57% decline in female bear abundance and density immediately following the food shortage, which coincided with increased bear use of development, and increases in bear mortality (e.g., vehicle collisions, lethal removals, and harvest). We also detected a change in spatial distribution of female bears with fewer occurring near human development after the food shortage, likely in response to high rates of mortality near human infrastructure. Given expected increases in climate-induced food shortages and human development, we expect that bear dynamics may be increasingly influenced by non-harvest human-caused mortality, which will be difficult to detect given current management approaches. To ensure long-term sustainability of bear populations, we recommend that wildlife agencies invest in approaches to improve monitoring of bear populations, explicitly incorporate non-harvest human-caused mortality into management models, and work to reduce non-harvest human-caused mortality, particularly in years with natural food shortages.
11:30AM Human Development and Climate Affect Hibernation in Black Bears with Implications for Human-Bear Conflicts
Heather E. Johnson; David L. Lewis; Tana L. Verzuh; Cody F. Wallace; Rebecca M. Much; Lyle K. Willmarth; Stewart W. Breck
Expanding human development and climate change are dramatically altering habitat conditions for wildlife, but little is known about the effects of these factors on hibernation behavior, a crucial life-history trait for many species. While shifts in animal hibernation can have ecological consequences for seasonal patterns of behavior and demography, they can also influence rates of human-wildlife conflicts, an issue of growing concern for wildlife managers. We investigated factors associated with the initiation, duration and termination of hibernation in black bears (Ursus americanus), a species that is strongly dependent on weather-related natural food productivity but will opportunistically forage on anthropogenic foods in developed landscapes. Using fine-scale data from 158 denning events of adult female black bears, we assessed the influence of anthropogenic food use, natural food availability, weather conditions and individual attributes on hibernation behavior. We found that individual attributes (i.e., reproductive status, age) were most strongly associated with denning chronology, but that external habitat influences (use of anthropogenic resources, natural food availability, and weather conditions) were also highly influential in shaping hibernation behavior. In the fall, black bears generally delayed hibernation when natural foods were abundant or when they used anthropogenic food subsidies, and emerged earlier in the spring with warmer temperatures. These patterns suggest that future changes in land-use and climate will decrease hibernation and increase the length of the ‘active’ season for black bears, likely resulting in subsequent increases in human-bear conflicts and human-caused bear mortalities. Numbers of bear conflicts and mortalities are commonly used by management agencies to index trends in black bear populations, but have the potential to be highly misleading when bear behavior is dynamically adapting to changing environmental conditions.
11:50AM Combining Resource Selection Functions, Space Use, and Systematic Conservation Planning to Identify Conservation Priorities for Brown Bears in the Romanian Carpathians
Mihai I. Pop; Ruben Iosif; Iulia V. Miu; Laurentiu Rozylowicz; Viorel D. Popescu
The spectacular recovery of large carnivores in the human-dominated landscapes of Europe has sparked a debate regarding the optimal landscape conditions in which carnivores can thrive and coexist with humans. As such, conservation planning has emerged as a key component for broad scale management of large carnivore populations. We use brown bears (Ursus arctos) in the Romanian Carpathians as a test case to develop a framework for identifying habitat conservation priorities based on a novel integration of resource selection functions, home range data, and systematic conservation planning algorithms. We used a comprehensive GPS telemetry dataset from 18 bears tracked between 2010 and 2014 in the Eastern Carpathians to (1) calculate seasonal home ranges using Brownian Bridge Movement Models, and (2) characterize seasonal population level habitat selection using Manly’s selection ratios. Seasonal home ranges were smallest during winter (18.5 ± 4.6 km2), and largest during the intense-feeding season (September-November: 102.5 ± 28.4 km2). Both males and females selected for mixed forest during winter and intense-feeding seasons, and for transitional woods and shrubs during low-feeding/reproductive and wild berries season. We then developed 2×2 km resolution proportional habitat layers for all habitat types used in the selection analysis, and used Manly’s selection ratios as weights for their respective habitat layers in the systematic conservation planning software Zonation. We integrated home range information as a parameter in the prioritization algorithm, and identified contiguous areas of high conservation value brown bear habitat during each season. Spatially, the winter habitat was the most dissimilar, and we identified large tracts of relatively undisturbed habitat that were selected across the four seasons as key habitats for brown bear conservation in the Carpathians. Overall, we show that common home range and habitat selection metrics can be combined with systematic conservation planning to identify biologically meaningful management and conservation priorities.

 

Contributed Paper
Location: Albuquerque Convention Center Date: September 25, 2017 Time: 10:30 am - 12:10 pm