Conservation and Ecology of Mammals V

Contributed Paper
ROOM: CC, Room 15
SESSION NUMBER: 90
 

1:10PM Examining Habitat Partitioning between Pennsylvania’s Apex Carnivores and a Common Prey Species (White-Tailed Deer Fawns)
Asia Murphy; David Miller; Duane Diefenbach
A key ecological question is how prey use habitat to avoid predators. We examined white-tailed deer (Odocoileus virginianus) fawn, black bear (Ursus americanus), coyote (Canis latrans), and bobcat (Lynx rufus) habitat use to determine whether there was overlap and how that might relate to which predators cause the most fawn mortality. We surveyed 354 camera points in three Pennsylvanian state forests during the summer (May-September) for three years (2015-2017). We used single-season occupancy models to examine how understory composition and landscape habitat variables were related to carnivore and fawn occupancy. We found that coyotes were 24 times more likely to occupy camera points in hemlock-mixed hardwood palustrine forest compared to mixed oak-mixed hardwood forest, and that, despite black bears and coyotes being the two major predators of fawns, black bear, coyote, and fawn habitat use did not overlap. We conclude that prey perception of predation risk might influence habitat use.
1:30PM Examining Exploratory Tendencies of Free-Ranging Coyotes Via Novel Object Testing
Katie E. Robertson; Shane C. McKenzie; Chris Anchor; Stanley D. Gehrt
As human influence has spread further into natural areas, some species have adapted their behaviors to live in proximity to people. The coyote (Canis latrans) has used its behavioral flexibility to ultimately thrive in natural, suburban, and urban settings. To survive in different environments and cope with various stressors, individuals within populations can express suites of related behaviors that form the basis of behavioral syndromes. While some individuals exhibit reactive (i.e., shy) behavioral patterns and others exhibit proactive (i.e., bold) behavioral patterns, each pattern likely has associated costs and benefits. One method of examining the exploratory tendencies of individuals is through novel object testing. To determine if coyotes vary in terms of exploratory behavior across an urbanization gradient, we conducted novel object tests (n=50) on free-ranging coyotes in the Greater Chicago Metropolitan Area. Reactions to objects were recorded via camera traps so coyote behaviors could be ranked along a neophobic-to-neophilic scale. Distributions of reactions along the scale varied by location type, with suburban and urban matrix areas tending to have more coyotes on the neophilic end of the spectrum than forest preserves (p < 0.001). A combination of neophobic and neophilic individuals were found in both matrix and forest preserve sites, however, suggesting there is some within-site, individual variation in coyote behavior, regardless of urbanization level. Our findings support the idea that exploration-prone animals are more common in urban areas, possibly due in part to their ability to find and successfully use novel resources.
1:50PM Variations in Reproduction and Age Structure in the North American River Otter in North Carolina
Charles W. Sanders; Christopher S. DePerno; Colleen Olfenbuttel; Dennis L. Stewart
The river otter (Lontra canadensis) is an important furbearer in North Carolina and international guidelines recommend monitoring the harvest through reproductive studies. We compared reproductive parameters and age-at-harvest of a reintroduced otter population in the Mountain Furbearer Management Region (MFMR) to the established populations in the Coastal Plain and Piedmont Furbearer Management regions (CPFMR and PFMR). Also, we compared our results with a study conducted from 1978-80 in the CPFMR. From 2009-15, in all three FMRs and from 1978-80 in the CPFMR, we collected otter carcasses from fur trappers. We extracted lower canine teeth for age analysis and removed female reproductive tracts to examine the ovaries and count fetuses. We collected data from 540 (2009-15=266; 1978-80=274) female otters. The age distribution was skewed in both time periods toward juveniles and yearlings (2009-2015: 57% [154/266]; 1978-80: 58% [160/274]). There was no difference in age distribution between time periods (p=0.8989) or the 3 FMRs (p=0.6559). We compared corpora lutea and fetus counts among FMRs for the 2009-15 dataset. The MFMR corpora lutea counts (2.59) were higher (p=0.0014) than the CPFMR (1.70) and PFMR (1.91). Litter sizes of adults (>2 years old) in the CPFMR between the two studies were similar (µ=2.6, p=0.9003); however, average reproduction was lower (µ=2.07, p<0.0001) among 2009-15 specimens versus 1978-80 (µ=2.97). While the 1978-80 study showed no reproductive subadults, the 2009-15 study showed subadult reproductive activity in the MFMR (100%), followed by the PFMR (83%), and CFMR (77%). The only difference among FMR means was between the MFMR (µ=2.22) and CFMR (µ=1.39, p=0.0080). North Carolina harvests approximately 2,000 otters annually and otters remain abundant across the state. A better understanding of the shift in the reproductive structure over time will inform the management decisions and aide other states in monitoring and reestablishing populations.
2:10PM Stable Isotopes and Home Range Areas as Tools to Evaluate Bias When Designating Black Bears as Food-Conditioned
Don W. Hardeman
As human development continues expanding into natural landscapes, increases in human-wildlife interactions are inevitable. This is particularly important for large carnivores because their interactions with humans often lead to conflict, resulting in their removal from the population. The ability of bears to adapt to changing environments and exploit the anthropogenic foods available in the human-dominated landscape increases the likelihood of human-bear conflict. How wildlife managers address human-bear conflict plays a pivotal role in shaping public perception of black bear conservation and management policy. Direct observation is often used to identify bears in human-use areas with the underlying assumption that the individual is food-conditioned or will become food-conditioned (FC). Using this method alone poses a problem because it incorporates limited information when deciding whether to euthanize a bear. Stable isotope analysis (SI) is an effective method to investigate bear diet and can aid in predicting the management status of individuals. Our objectives were to 1) identify bears consuming anthropogenic foods, 2) predict whether unknown bears in human-use areas were FC, and 3) utilize home range analysis and SI to predict the management status of black bears collared on the human-wildland interface. We used a discriminant function analysis to build an isotopic model of a FC bear using hair samples from individuals removed for consuming human food. We used this model to predict the status of unknown management bears captured in human-use areas and bears on the human-wildland interface. Our results indicated that the majority of bears known apriori to be FC were correctly identified, but only 60% of unknown management bears removed were identified as FC. We found that home-range analysis explained the management status of our collared bears. Based on our results, we suggest using a combination of methods when identifying bears that may be of management concern.
12:50PM Deer Use of Jumpouts Ramps and Factors Influencing Wildlife Use of Undercrossings along a Highway with Wildlife Exclusion Fencing
Alex Jensen; John Perrine; Andrew Schaffner; Nancy Siepel; Morgan Robertson
Highways can fragment habitat and wildlife-vehicle collisions (WVCs) can be a significant mortality source for wildlife, as well as a human safety concern. Wildlife exclusion fencing has been shown to reduce WVCs, but can also trap animals near the road if they enter at access roads or at fence ends. Earthen escape ramps (“jumpouts”), have been proposed as a possible solution, but they remain relatively untested. We used wildlife cameras to document mule deer (Odocoileus hemionus) activity at 4 jumpout ramps within a 2.5-mile wildlife exclusion fence project along Highway 101 near San Luis Obispo, California, from 2012-2017. We aimed to determine the rate at which the deer used the jumpouts, and how group demographics influenced jumpout use. Deer never “reversed” the jumpout to enter the highway corridor, and when at the top of ramp only jumped out 20% of the time. However, two-thirds of our events were pseudoreplicates; two groups of female deer accounted for nearly half of the activity at the jumpouts. We also documented wildlife use of undercrossings in the same area from 2012-2017. We were interested in determining which factors were related to mountain lion (Puma concolor), black bear (Ursus americanus), mule deer, and bobcat (Lynx rufus) activity. Dimensionality and distance to cover were related to deer and bobcat activity, but not mountain lion and bear activity. Whether or not the undercrossings were within the fenced zone was related to the activity of all four species, and substrate was related to activity for all species except bear. To our knowledge, this is the largest dataset ever collected on jumpouts, and undercrossings are rarely monitored for more than two years. This 5-year dataset allowed us to account for temporal variation, with the goal of reducing WVCs while facilitating regional connectivity.

 

Contributed Paper
Location: Cleveland CC Date: October 11, 2018 Time: 12:50 pm - 2:30 pm