EFFECTS OF ELECTRIC FENCE PERMEABILIY ON GRIZZLY AND BLACK BEARS IN THE BLACKFOOT VALLEY OF MONTANA (POSTER)

Increasing agriculture-bear conflicts on private lands require innovative approaches to conserve wildlife while also conserving the economic viability of Montana farmers and ranchers.  Electric fencing has been an effective tool for deterring bears from calving areas and bee yards.  Recent advances in electric fencing materials, as well as automated deployment devices, have reduced costs and increased interest in using electric fencing to deter bears from larger areas, like crop fields. Scientific evaluations of the efficacy of temporary electric fencing at deterring grizzly (Ursus arctos) and black bears (Ursus americanus) are lacking. Additionally, large-scale installations of electric fencing may impact bear movements and habitat use.  In 2015, we began a multi-faceted study in the Blackfoot Valley to evaluate A) the efficacy of various rapid-deployment electric fencing designs in deterring bears from agricultural lands, and B) landscape level space use and permeability of agricultural lands relative to electric fences.  Baited enclosures of 2-3 fencing configurations were established in the valley during the spring of 2015.  Each enclosure is systematically energized and unenergized for 3-day periods throughout the spring and summer; passage into the enclosure is monitored with motion-activated trail cameras to provide information on configuration effectiveness and permeability.  In addition, we established 60 randomly selected camera trap stations throughout the valley to evaluate landscape-level habitat use relative to landscape metrics and electric fences.  Daily movement locations provided by 5 grizzly bears fitted with GPS collars will provide individual-level information on seasonal movements and habitat selection relative to habitat conditions and electric fences

Predicting the Spatial Distribution of Human-Black Bear Interactions Across an Urban Area

Human (Homo sapiens)-black bear (Ursus americanus) interactions are increasing throughout North America. Information that assists managers in developing methods to reduce conflicts is lacking. We used human-bear incident data, i.e., phone complaints and conflicts, collected in Missoula, Montana, by Montana Fish, Wildlife and Parks from 2003-2008 to describe the attractants and human impacts of incidents, and develop a model that predicts the spatial probability of incidents. We combined the locations of black bear sightings (n = 307), other incidents, e.g., bear seen feeding on garbage (n = 549), and sites where proactive management actions were carried out (n = 108), and compared them to 5000 random locations using logistic regression. Based on literature, we used distance to forested patches, distance to water, and housing density as variables in our model. Garbage (38%), fruit trees (10%), and bird feeders (7%) were the most common attractants at incident sites, and some incidents resulted in threats to human safety (9%) and property damage (7%). All variables were significant in the predictive model, and the model performed well at discriminating the relative spatial probability of incidents (rs = 0.782; P < 0.01). The probability of incidents increased when residents lived close to forested patches, close to water, and in intermediate housing densities (~ 6.6 houses/ha). Our results suggest that spatial patterns in human-black bear interactions are predictable and these patterns can be used to understand the potential for conflict in developing areas and to identify areas where preventative management is necessary

Estimation of Sustainable Mortality Thresholds for Grizzly Bears in the Northern Continental Divide Ecosystem

Habitat management and limits on mortality have led to population growth and sizable range expansion for the federally-listed grizzly bear population in the Northern Continental Divide Ecosystem (NCDE), Montana.  Human-caused mortality has coincidentally increased, but it is not clear what level of human-caused mortality would cause the population to decline. A record of annual documented mortalities of independent (?2 years old) bears is maintained for the NCDE, from which an estimate of the total number of mortalities is generated.  Our goal was to estimate sustainable survival rates for independent bears and to develop realistic thresholds for sustainable mortality, which could be applied to these annual estimates.  We estimated survival and recruitment rates using 662 bear-years of telemetry data, performed stochastic modeling, and estimated the annual growth rate as 1.023 and annual population size as 765–960 during 2004–2014.  We then evaluated minimum independent survival rates consistent with a stable to increasing trend, and integrated these sustainable rates with model-estimated population size and mean estimates of total annual independent bear mortality to establish mortality thresholds.  During 2004–2014, estimates of total annual mortality were highly variable, but averaged 13.8 for females and 16.4 for males.  For females and males, respectively, these estimates accounted for only 69% (range 28–168%) and 62% (28–121%) of sustainable mortality thresholds, indicating that approximately 6 and 10 additional annual mortalities could have been sustained without the population declining.  Application and periodic reevaluation of mortality thresholds will help managers reach or maintain a target population size for grizzly bears in the NCDE

Grizzly/Brown Bears

Grizzly/brown bears (Ursus arctos) of the world include numerous subspecies in Asia, Europe, and North America. The interior grizzly (Ursus arctos horribilis) is generally smaller than the coastal (Ursus arctos gyas) or island (Ursus arctos middendorffi) subspecies of North American brown bear, and it has the classic “grizzled” hair tips. Brown bears in general are very large and heavily built. Wherever brown bears live, their size is influenced by their subspecies status, food supply, and length of the feeding season. Bone growth continues throughthe sixth year, so subadult nutrition often dictates their size potential. Brown bears are typically brown in color, but vary from pure white to black, with coastal brown bears and Kodiak bears generally lighter, even blond or beige. The interior grizzly bears are typically a dark, chocolate brown or black, with pronounced silver tips on the guard hairs. This coloration often gives them a silvery sheen or halo. They lack the neck ruff of the coastal bears, and grizzlies may even have light bands before and behind the front legs. The interior grizzly’s “hump,” an adaptation to their digging lifestyle, is seen less in the coastal brown bears, polar bears, or black bears. The brown bears (including the grizzly) are also characterized by their high eye profile, dish-shaped face, and short, thick ears

Jean Dickson Jonkel Reminiscence, circa 2000

In this self-recorded reminiscence, Jean Jonkel, who graduated from the University of Montana [UM] in 1940, recounts her experiences at the University and the professors she enjoyed such as J.P. Rowe, “Psych” Smith, and J. Earl “Burly” Miller. She recalls funny stories about dogs sleeping in classrooms and students protesting bad lecturing by walking out of class. Jonkel speaks fondly of Madame Arnoldson who taught music, including a course of French opera which she held at her home. Jonkel credits Dr. G. D. Shallenberger for helping her look for a job after she graduated, and Dr. A. H. Weisberg for helping her pass German. Jonkel describes her admiration of “Burly” Miller’s teaching style and her disappointment when he moved into an administrative role and quit teaching English history. She discusses how she convinced her husband to attend the University of Montana after World War Two, and briefly mentions his experiences at the University.https://scholarworks.umt.edu/umhistory_interviews/1029/thumbnail.jp

Ecology, population dynamics, and management of the black bear in the spruce-fir forest of Northwestern Montana

This research was designed to study the ecology and population dynamics of black bears in the spruce and fir forest of northwestern Montana, to test the hypothesis that extrinsic factors caused fluctuations in population numbers, and to develop management principles for bears. The rough topography and moderate to heavy precipitation on the Big Creek study area have created varied ecological conditions which in many ways are excellent for black bears. Seral and climax stands of the Picea-Abies/ Pachistima myrsinites association are used most extensively by bears, but other vegetative types are important seasonally. The home ranges of adult bears on the area are small and they remain the same size from year to year. As resident males mature, however, their ranges increase in area. Bears do congregate, but only where there is an overlap in their home ranges. Even then they do not form compact groups, but keep at least 50 yards (48 metres) between individuals. Many adult females (bears approximately 4-1/2 years or older) do not have young, apparently because of the failure of females to ovulate, prenatal mortality, and early mortality. Tentative conclusions suggest that seasonal restrictions in nutrition delay the physical maturity and thereby the sexual maturity of some bears. These restrictions are caused by the climate of Big Creek and are detrimental even to adult females on certain years. Inadequate nutrition is also suggested by the observation that some yearlings inhibit estrus for two years by suckling up to 16 months of age. The nutrition of adult males and of many adult females generally is excellent, however. Litter sizes on Big Creek and throughout the West are smaller than in eastern North America, but apparently the cause is genetical rather than nutritional. The survival of cubs is high (95 per cent) from 1/2 to 1-1/2 years of age while they are with their mothers, but all sub-adults are physically weak in late spring and natural loss is considerable among sub-adults 1-1/2 to 3-1/2 years old. They appear especially vulnerable to changes in climate, parasitism, predation, food quantity and quality, and the behaviour of adult bears. Many sub-adult males disperse from the area. Annual changes in the density of bears on Big Creek are caused in part by man, by dispersal of sub-adults, and through changes in the reproductive success of adults and the natural mortality of sub-adults. The numbers of adults on the area remain relatively constant from year to year. Even though food is unlimited during some seasons, a form of territoriality within "social groups" spaces the bears on Big Creek and ultimately exerts a definite control over density. The density is relatively high on Big Creek and probably results in more social interaction and territoriality than in bears elsewhere. Longer care of young, smaller litter sizes, and increased social organization all seem evident as reactions to the Big Creek environment. Extrinsic and intrinsic forces unite, therefore, in population regulation, and the net result is the creation of an excellent habitat for adult black bears, but an harsh, environment for sub-adults after they have left their mothers.Science, Faculty ofZoology, Department ofGraduat