Paul R. Krausman

Food availability and foraging near human developments by black bears

Abstract Understanding the relationship between foraging ecology and the presence of human-dominated landscapes is important, particularly for American black bears (Ursus americanus), which sometimes move between wildlands and urban areas to forage. The food-related factors influencing this movement have not been explored, but can be important for understanding the benefits and costs to black bear foraging behavior and the fundamental origins of bear conflicts. We tested whether the scarcity of wildland foods or the availability of urban foods can explain when black bears forage near houses, examined the extent to which male bears use urban areas in comparison to females, and identified the most important food items influencing bear movement into urban areas. We monitored 16 collared black bears in and around Missoula, Montana, during 2009 and 2010, while quantifying the rate of change in green vegetation and the availability of 5 native berry-producing species outside the urban area, the rate of change in green vegetation, and the availability of apples and garbage inside the urban area. We used parametric time-to-event models in which an event was a bear location collected within 100 m of a house. We also visited feeding sites located near houses and quantified food items bears had eaten. The probability of a bear being located near a house was 1.6 times higher for males, and increased during apple season and the urban green-up. Fruit trees accounted for most of the forage items at urban feeding sites (49%), whereas wildland foods composed <10%. Black bears foraged on human foods near houses even when wildland foods were available, suggesting that the absence of wildland foods may not influence the probability of bears foraging near houses. Additionally, other attractants, in this case fruit trees, appear to be more important than the availability of garbage in influencing when bears forage near houses.

Vigilance in Cattle: The Influence of Predation, Social Interactions, and Environmental Factors

Abstract Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% ± 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% ± 0.46%) as those without calves (2.0% ± 0.27%). Single cattle and groups of two to five exhibited higher vigilance rates (4.2% ± 0.79%) than groups of six to 20 (2.5% ± 0.32%) and groups of > 20 (3.0% ± 0.41%). Cattle in groups of > 20 increased vigilance as visual obstruction increased. Mother cows whose calves were preyed upon (n = 5) exhibited a 3% to 48% increase in vigilance within 3 d after their calves were killed; this rate returned to near baseline levels after 10 d. Conversely, mother cows reduced foraging after their calves were killed from 88.5% ± 1.69% to 43.5% ± 11.4%; foraging rate also returned to near baseline levels after 10 d. Cattle exhibit vigilance at lower levels compared to wild ungulates, but this behavior appears to be at least partially an antipredatory behavior. Our findings provide support that predators can influence cattle behavior.

Observations of Coyote-Cat Interactions

Abstract Coyotes (Canis latrans) pose a risk to domestic cats (Felis catus). We captured, radiocollared, and tracked 8 coyotes from November 2005 to February 2006 for 790 hours in Tucson, Arizona, USA. We observed 36 coyote–cat interactions; 19 resulted in coyotes killing cats. Most cats were killed in residential areas from 2200 hours to 0500 hours during the pup-rearing season. Single coyotes were as effective killing cats as were groups (>1) of coyotes. Documented cases of predators killing cats could encourage cat owners to keep their cats indoors and assist wildlife managers in addressing urban wildlife issues.

Predicting spatial distribution of human–black bear interactions in urban areas†

ABSTRACT Human—wildlife interactions are often associated with a myriad of stakeholder groups, intense political scrutiny, and limited biological data, creating complex decision-making situations for wildlife management agencies. Limited research exists on the development and testing of tools (e.g., models to predict the spatial distribution of interactions) to reduce human—black bear (Ursus americanus) interactions (HBI). Available models predicting spatial distribution of HBI are usually developed at scales too large to predict across urban areas, are rarely tested against independent data sets, and usually do not incorporate both landscape and anthropogenic variables. Our objective was to develop a predictive modeling tool that could identify areas of high conflict potential across urban landscapes. We compared locations of HBI in Missoula, MT, recorded by Montana Fish, Wildlife & Parks from 2003 to 2008, to random locations using logistic regression. The final model discriminated the relative spatial probability of HBI within Missoula well, and a second study area moderately. The probability of HBI in Missoula increased when residents lived close to forested patches and major rivers and streams and in intermediate housing densities (approx. 6.59 houses/ ha). Our results provide a wildlife management tool and a repeatable statistical framework that predicts spatial distribution of HBI using only a small set of variables.

Livestock Grazing, Wildlife Habitat, and Rangeland Values

livestock and wildlife values should be placed within this broader context. Ranchers and conservationists in the West realize that debates over grazing systems and stocking rates are of little consequence if rangelands continue to be lost or fragmented due to subdivision, farming, weed invasion, catastrophic wildfi re, and energy development. However, impacts of domestic grazing that diminish land value via reduced range productivity and wildlife habitat quality can also lead to alternative land uses and habitat conversion. Maintaining the multiple values of western rangelands will require a shift from local to landscape conservation to match the scale of land use change that threatens grazing, rural ways of life, and wildlife habitat. The future of western rangelands is in developing partnerships that help keep sustainable grazing the prevailing land use. Indeed, as rangelands are lost to other land uses, overlapping interests will make conservation partners out of otherwise odd associates—ranchers need open space for grazing and wildlife biologists, managers, and other conservationists want to maintain or enhance the wildlife values on working ranches. In this paper, we review a representative sampling of scientifi c literature to document grazing impacts on wildlife and its habitat to better understand the roles of grazing strategies in wildlife habitat conservation. Further, we explore commonalities between grazing and conservation interests and provide a vision for advancing wildlife and habitat management and conservation.

Bison Versus Cattle: Are They Ecologically Synonymous?

Abstract Historically, the plains bison (Bison bison Linnaeus) was the most numerous and influential grazer on the Great Plains. Today 500u200a000 bison occupy North America among more than 100u200a000u200a000 cattle. In an attempt to restore their historical ecological role, bison are translocated onto landscapes previously manipulated for cattle use through water and fence development. We hypothesized that bison would use these landscapes similarly to cattle, thus maintaining homogenous grazing and reducing the restoration potential of bison at a landscape scale. We quantified differences between bison populations at different locations and spatial scales (American Prairie Reserve, Malta, Montana, USA, and Grasslands National Park, Val Marie, Saskatchewan, Canada, 2010–2011) and bison and cattle at similar locations and spatial scales using behavioral observations, movement analyses, and resource selection functions. Bison and cattle differed in all behaviors (grazing, standing, bedded, moving, other); however, landscape attributes resulted in behavior differences within species. Cattle spent a higher proportion of time grazing (45–49%) than bison (26–28%) and increased time at water. Bison moved at a 50–99% faster rate than cattle, and first passage time movement analyses identified selection of bison foraging patches (11u200a690 ha) larger than cattle foraging patches (48–615 ha). Similar to cattle, bison avoided most vegetation communities in relation to riparian communities and selected areas closer to water. Cattle selected for high plant biomass, whereas bison selected for intermediate plant biomass. This study has implications when bison and cattle are used to meet prairie restoration objectives. For bison, large landscapes that include variation in topography and vegetation communities are required. Furthermore, limiting manmade water sources may facilitate bison grazing patterns that more closely approximate historical bison use. For livestock, reduced movement and increased time spent grazing encourage grazing practices that increase heterogeneous grazing at a pasture scale.

Fire History in a Chaparral Ecosystem: Implications for Conservation of a Native Ungulate

Abstract Mature chaparral vegetation in the San Gabriel Mountains, California, resulting from long fire-return intervals (50–70 yr), has resulted in reduced visibility and availability and quality of forage, all of which are important attributes of mountain sheep (Ovis canadensis) habitat. Concomitantly, vegetation changes have decreased availability and quality of forage. We developed a resource-selection model to determine the effect of fire history on habitat use by mountain sheep, examined the hypotheses that habitat selection was associated with fire occurrence, and determined whether fire occurrence influenced the amount of potential habitat available to mountain sheep. The best model indicated that mountain sheep selected vegetation that had burned within 15 yr and avoided areas that had not burned within that time frame. We then used our model to quantify potential changes in mountain sheep habitat that have occurred over time based on fire conditions. We identified 390 km2 of mountain sheep habitat that existed in 2002 (when only 63 mountain sheep were tallied), 486 km2 in 1980 (when the mountain sheep population was at its highest), and 422 km2 in 2004 (just after a series of large wildfires). We also estimated that 615 km2 of suitable habitat would be available in a hypothetical situation in which the entire study area burned. Our results suggest that restoration of mountain sheep to their historical distribution in chaparral ecosystems will depend upon more frequent fires in areas formerly occupied by those specialized herbivores.

Behavioral and attitudinal change of residents exposed to human–bear interactions

Abstract Human–black bear (Ursus americanus) interactions (HBI) have been increasing in frequency and magnitude in North America since the 1960s, and many wildlife management agencies are turning to proactive management actions to reverse this trend. Information and education efforts (IEE) are the most common proactive management actions used; however, few studies monitor behavior and attitudes of residents exposed to HBI and IEE. We used a case study in the Rattlesnake Valley of Missoula, Montana, USA to describe the diversity of anthropogenic attractants available to black bears based on self-reported human behaviors, and to test for changes in resident behavior and attitudes over a 4-year exposure to HBI and IEE. We identified >5 non-vegetative attractants, and >12 species of native and non-native vegetation available to black bears. Comparing the responses from mail questionnaires in 2004 (n u200a=u200a 369, response rate u200a=u200a 74%) and 2008 (n u200a=u200a 560, response rate u200a=u200a 60.1%), we found that the prevalence of 1 important behavior (outdoor garbage storage) decreased, and support for management actions used to deal with HBI increased, suggesting behavior and attitudes of residents changed from 2004 to 2008. We suggest that bear managers developing proactive management plans for HBI must incorporate (1) the varying effects of reducing the prevalence of 1 or numerous attractants, (2) the changing dynamics of human behavior and attitudes, and (3) the importance of incorporating monitoring and evaluation procedures.

Experimentally Derived δ13C and δ15N Discrimination Factors for Gray Wolves and the Impact of Prior Information in Bayesian Mixing Models

Stable isotope analysis of diet has become a common tool in conservation research. However, the multiple sources of uncertainty inherent in this analysis framework involve consequences that have not been thoroughly addressed. Uncertainty arises from the choice of trophic discrimination factors, and for Bayesian stable isotope mixing models (SIMMs), the specification of prior information; the combined effect of these aspects has not been explicitly tested. We used a captive feeding study of gray wolves (Canis lupus) to determine the first experimentally-derived trophic discrimination factors of C and N for this large carnivore of broad conservation interest. Using the estimated diet in our controlled system and data from a published study on wild wolves and their prey in Montana, USA, we then investigated the simultaneous effect of discrimination factors and prior information on diet reconstruction with Bayesian SIMMs. Discrimination factors for gray wolves and their prey were 1.97‰ for δ13C and 3.04‰ for δ15N. Specifying wolf discrimination factors, as opposed to the commonly used red fox (Vulpes vulpes) factors, made little practical difference to estimates of wolf diet, but prior information had a strong effect on bias, precision, and accuracy of posterior estimates. Without specifying prior information in our Bayesian SIMM, it was not possible to produce SIMM posteriors statistically similar to the estimated diet in our controlled study or the diet of wild wolves. Our study demonstrates the critical effect of prior information on estimates of animal diets using Bayesian SIMMs, and suggests species-specific trophic discrimination factors are of secondary importance. When using stable isotope analysis to inform conservation decisions researchers should understand the limits of their data. It may be difficult to obtain useful information from SIMMs if informative priors are omitted and species-specific discrimination factors are unavailable.

Spatial and temporal interactions of sympatric mountain lions in Arizona

Spatial and temporal interactions among individual members of populations can have direct applications to habitat management of mountain lions (Puma concolor). Our objectives were to evaluate home range overlap and spatial/temporal use of overlap zones (OZ) of mountain lions in Arizona. We incorporated spatial data with genetic analyses to assess relatedness between mountain lions with overlapping home ranges. We recorded the space use patterns of 29 radio-collared mountain lions in Arizona from August 2005 to August 2008. We genotyped 28 mountain lions and estimated the degree of relatedness among individuals. For 26 pairs of temporally overlapping mountain lions, 18 overlapped spatially and temporally and eight had corresponding genetic information. Home range overlap ranged from 1.18% to 46.38% (