Conservation and Ecology of Mammals III

Contributed Paper
ROOM: Rooms 16 – Acoma, 32 – Teseque and 15 – Zuni Combined
SESSION NUMBER: 64
 

10:30AM The Inefficiency of Harvest-Based Selection In Ungulates
James Heffelfinger; Kevin Monteith; Ryan Long; R. Terry Bowyer; Vernon Bleich; Paul Krausman; Tayler LaSharr
Most hunters are not selective in the type of animal they take, satisfied instead to harvest any legal animal. In a few exceptions, however, regulations may force the harvest of animals of a minimum size or age regardless of the hunters’ personal choice. Harvest of animals with specific traits more so than those without has led some to argue that such selection can cause evolutionary change that may be detrimental to the species, especially if those traits are related positively to individual fitness. Using information from a broad range of aquatic and terrestrial systems exposed to a myriad of potential and operational selective pressures, several authors have made expansive generalizations about selective harvest and its applicability to ungulates. Harvest-based selection can be intensive enough to be relevant in an evolutionary sense, but phenotypic changes consistent with hunter selection often are confounded with multiple environmental influences. Factors such as age, genetic contribution of females, nutrition, maternal effects, epigenetics, patterns of mating success, gene linkage, movements, refugia, date of birth, and other selective pressures interact with harvest to impede unidirectional evolution of a trait. The intensity of selection determines potential for evolutionary change in a meaningful temporal framework. Indeed, only under severe intensity, and strict selection on a trait could harvest prompt evolutionary changes in that trait in the face of other more influential factors. Broad generalizations across populations or ecological systems can yield erroneous extrapolations and inappropriate assumptions. Removal of males expressing a variety of horn or antler sizes, including some very large males, does not inevitably represent artificial selection unless the selective pressures are intensive enough to cause a unidirectional shift in phenotype or allele frequencies that may act on some relevant life-history trait or process. Understanding harvest-based selection warrants full consideration of the inefficiency of selection.
10:50AM The Landscape of Fear May Play a Minimal Role in the Spatiotemporal Distribution of Urban Mammals
Travis Gallo; Mason Fidino; Elizabeth Lehrer; Seth Magle
Cities are a hodgepodge of isolated habitat patches intermixed in a matrix of buildings and asphalt. Within, the presence or absence of a species is often correlated to environmental features of the landscape (e.g., housing density) or land-use type, thereby ignoring other forms of habitat selection. For instance, as predators and their prey exist within these highly heterogeneous landscapes, the presence of a predator likely plays an important role in the spatiotemporal distribution of its prey. We assessed the spatial overlap of two prey species – white tailed deer (Odocoileus virginianus) and eastern cottontail (Sylvilagus floridanus) – and a common predator – coyote (Canis latrans) – in Chicago, IL USA using a Bayesian two-species co-occurrence model. We also compared the temporal activity of white-tailed deer and eastern cottontails at sites where coyotes were detected and not detected. We found that the probability of predator avoidance for either prey species was low. Spatial overlap between predator and prey was likely based on chance (species interaction factors = 1), and daily activity patterns of both prey species varied relatively little at sites where coyotes were detected compared to sites where coyotes were not detected (deer daily activity overlap = 95%; cottontail activity overlap = 83%). Our results indicate that urbanization may create a novel arrangement of habitat patches that alters expected predator-avoidance behaviors of prey species. Thus, our current theories on how and why animals distribute themselves across a landscape may differ in highly urbanized areas. How wildlife are distributed can reveal useful information for reducing human-wildlife interactions, an important component of urban wildlife management. Therefore, common paradigms should be further assessed in urban environments to better inform management decisions.
11:10AM A Dollar Out of Fifteen Cents: Estimating Fosa (Cryptoprocta ferox) Density in Northeastern Madagascar from Sparse Data
Asia Murphy; Brian Gerber; Marcella Kelly; Sarah Karpanty; Felix Ratelolahy; Zach Farris
Globally, apex predators are threatened and in decline. Many surveys of apex predators result in sparse detections that make it difficult to assess their population status. The fosa (Cryptoprocta ferox) is Madagascar’s native apex predator and it is believed that the Zahamena-Mantadia-Vohidrazana and Makira-Masoala rainforest complexes are the only protected areas large enough to hold fosa populations exceeding 300 individuals; however, both areas are lacking density estimates. We estimated fosa density using spatial mark-resight analyses of data collected during camera trapping surveys in the Masoala-Makira complex (2008-2015). We examined the response of fosa density and movement to habitat degradation and season, monitored annual density trends across seven years at two sites, and estimated fosa region-wide population size. We obtained a mean of 16.1 (SE 0.52; range: 2-49) fosa detections and three observers identified a mean of 3.62 (SE 0.09; range: 1-8) marked individuals per survey. Fosa daily baseline encounter rate was very low (λ0 = 0.004; 0.003-0.006) and density/movement estimates were similar across forest types and between seasons. There appeared to be declines in fosa density at resurveyed sites. Region-wide fosa abundance extrapolated from local density estimates was estimated to be 1,061 (95% HPDI: 596 – 1,780) adult individuals. This represents a significant portion of the global fosa population. By combining detections across surveys, we overcame issues associated with sparse data that often plague surveys for apex predators and obtained valuable information on fosa population size, which will allow us to better assess its status and prioritize conservation actions.
11:30AM Habitat Use and Movement Patterns of Wildlife on the Kenai Peninsula, Alaska Informs Mitigation Strategies for Highways
Lowell H. Suring; William L. Gaines; James S. Begley
The Alaska Department of Transportation and Public Facilities in cooperation with the Federal Highway Administration, was seeking to improve the Sterling Highway on the Kenai Peninsula, Alaska. These improvements provided the opportunity to address the effects of the Highway on wildlife movements and wildlife-vehicle collisions. We evaluated the movement patterns of 6 focal species (i.e., brown bear [Ursus arctos], black bear [Ursus americanus], wolverine [Gulo gulo], Canada lynx [Lynx canadensis], moose (Alces americanus), Dall sheep [Ovis dalli]). Our focus was on the potential influence of the existing alignment of the Sterling Highway on movement patterns and on mitigation of those effects. The objectives were to describe: 1) habitat use by the focal species, 2) potential movements and movement corridors of focal species, and 3) management actions suitable to mitigate the potential effects of the Sterling Highway Project on those movement corridors. We used Resource Selection Functions and Bayesian Networks to describe habitat quality for the focal species and Least Cost Corridor (LCC) and Circuit Theory (CT) analyses to describe potential movement corridors. A field evaluation of model results was conducted using camera trapping. Individual findings for the 6 focal species were combined to create corridor hot spots. Analysis of LCCs showed multiple potential corridors for all focal species (some by sex and season) within the project area. CT analyses helped us estimate the effective resistance of the landscape within these corridors and identify potential primary crossing points. The field evaluation generally supported our findings. Crossing points for all focal species were commonly characterized by lower total road density, proximity to a major drainage, rugged terrain, and high quality habitat. Results of the analyses of individual species and development of corridor hot spots allowed us to recommend sections of the existing Highway where mitigation measures would likely be successful.

 

Contributed Paper
Location: Albuquerque Convention Center Date: September 26, 2017 Time: 10:30 am - 12:10 pm