Individual Distinctiveness in Brown Bears,Ursus arctos L

Individual brown bears, Ursus arctos, behave differently from each other. Consistent behavioural differences suggest that each bear has its own distinct personality. On Admiralty Island in south-eastern Alaska, we collected longitudinal data during three years of summer salmon runs on seven individual brown bears that could be recognized from year to year. Bears fed on vegetation and on salmon along a tidal creek. Ratings of individual bears by observers on different aspects of behaviour, comparisons of behavioural frequencies, and long-term observations of individual activities served to assess personality differences. Individual bears varied in five ways: 1. Some bears were lively, animated and playful in social situations and during solitary activities such as travelling or fishing. Other bears' movements and general demeanour seemed dull and humourless; 2. Some bears were irascible, others socially uninvolved and unreactive; 3. Some bears were expert at fishing but others fished ineptly; 4. Some bears were confident with other bears but others lacked confidence in social situations; 5. Some bears were often active and alert. Others rested more frequently and for prolonged periods.     

Population-level resource selection by sympatric brown and American black bears in Alaska

Distribution theory predicts that for two species living in sympatry, the subordinate species would be constrained from using the most suitable resources (e.g., habitat), resulting in its use of less suitable habitat and spatial segregation between species. We used negative binomial generalized linear mixed models with fixed effects to estimate seasonal population-level resource selection at two spatial resolutions for female brown bears (Ursus arctos) and female American black bears (U. americanus) in southcentral Alaska during May–September 2000. Black bears selected areas occupied by brown bears during spring which may be related to spatially restricted (i.e., restricted to low elevations) but dispersed or patchy availability of food. In contrast, black bears avoided areas occupied by brown bears during summer. Brown bears selected areas near salmon streams during summer, presumably to access spawning salmon. Use of areas with high berry production by black bears during summer appeared in response to avoidance of areas containing brown bears. Berries likely provided black bears a less nutritious, but adequate food source. We suggest that during summer, black bears were displaced by brown bears, which supports distribution theory in that black bears appeared to be partially constrained from areas containing salmon, resulting in their use of areas containing less nutritious forage. Spatial segregation of brown and American black bears apparently occurs when high-quality resources are spatially restricted and alternate resources are available to the subordinate species. This and previous work suggest that individual interactions between species can result in seasonal population-level responses.     

Individual Effects of Seasonal Changes,Visitor Density,and Concurrent Bear Behavior on Stereotypical Behaviors in Captive Polar Bears (Ursus maritimus)

Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.     

Grizzly Bear Behavior and Global Positioning System Collar Fix Rates

Abstract: Animal locations collected by Global Positioning System (GPS) collars will represent a biased sample of the sites an animal used if some position fixes fail and if those missed locations do not occur randomly. Probability of a GPS receiver obtaining a position fix is known to decline as canopy cover increases, but the impact of forest canopy cover was insufficient to account for the low fix rates we observed for GPS collars on grizzly bears (Ursus arctos). We tested the hypothesis that GPS fix rates were related to the interaction between animal activity (active vs. resting) and canopy cover by evaluating the following predictions: 1) grizzly bear activity should follow a circadian pattern similar to the circadian fix-rate pattern, 2) grizzly bear use of canopy cover should follow a circadian pattern similar to the circadian fix rates, 3) grizzly bear activity should be related to canopy cover (i.e., bears should rest in areas with relatively high canopy covers and feed and move in relatively open areas), and 4) collar orientation and canopy cover should interact to affect the fix rates of test collars. The GPS fix rates traced a bimodal circadian pattern that was directly related to the circadian pattern of grizzly bear activity. Fix rates declined when bears were more likely to be using denser cover, and fix rates of test collars demonstrated that collar orientation interacted with canopy cover, such that fix rates declined much more with increasing canopy cover when the collar was on its side than when the collar was upright. We concluded that inferences made about grizzly bear microhabitat use, based on GPS locations, will underrepresent high canopy cover sites, especially when grizzly bears are resting there. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):596–602; 2008)     

Habitat use by black bears in relation to conspecifics and competitors

Sympatric black bears (Ursus americanus) and brown bears (Ursus arctos) are common in many boreal systems; however, few predator assemblages are known to coexist on a single seasonally abundant large prey item. In lowland southwestern interior Alaska, black bears and brown bears are considered the primary cause of moose (Alces alces) calf mortality during the first 6 weeks of life. The objective of this study was to document habitat use of global-positioning system (GPS)-collared black bears during peak and non-peak seasons of black bear-induced and brown bear-induced moose calf mortality within southwestern interior Alaska, in spring 2002. We compared habitats of GPS-collared black bears to those of presumably uncollared black bears and brown bears at their moose calf mortality sites. Results from this study suggest that GPS-collared black bears use similar habitat as conspecifics more than expected during the peak period of black bear predation on moose calves, whereas they use habitat in proportion to home range availability during the peak in brown bear predation on moose calves. Sex-specific Ivlev's electivity indices describe greater than expected use of mixed-deciduous forest and needleleaf forest by male GPS-collared black bears during the peak of moose calf predation, whereas females have a tendency to use these habitats less than expected. Juvenile GPS-collared black bears largely use the same habitat as other sympatric predators during the peak of moose calf predation, whereas during the non-peak period juveniles use opposite habitats as adult GPS-collared black bears. The outcome of this study offers possible explanations (e.g., sex, age) for spatial overlap or segregation in one member of a complex predator guild in relation to a seasonal pulse of preferred prey.     

Genetics and conservation of European brown bears Ursus arctos

• 1 We review the genetics research that has been conducted on the European brown bear Ursus arctos, one of the genetically best‐studied mammalian species.
• 2 The first genetics studies on European brown bears were on phylogeography, as a basis for proposed population augmentations. Two major mitochondrial DNA lineages, western and eastern, and two clades within the western lineage were found. This led to a hypothesis that brown bears had contracted to southern refugia during the last glacial maximum. More recent results suggest that gene flow among brown bears blurred this structure and they survived north of these putative refugia. Thus, today's structure might be a result of population fragmentation caused by humans.
• 3 The nuclear diversity of European brown bears is similar in range to that in North American bears: low levels occur in the small populations and high levels in the large populations.
• 4 Many non‐invasive genetic methods, developed during research on brown bears, have been used for individual identification, censusing populations, monitoring migration and gene flow, and testing methods that are easier to use in endangered populations and over large areas.
• 5 Genetics has been used to study many behavioural and population ecological questions that have relevance for the conservation and management of brown bears.
• 6 The European brown bear has served, and will continue to serve, as a model for the development of methods, analyses and hypotheses in conservation genetics.

     

Introducing a semi-naturalistic exhibit as structural enrichment for two brown bears (Ursus arctos). Does this ensure their captive well-being?

In this study we used the daily activity pattern and use of space as indicators of change in the program of structural enrichment, implemented with 2 subjects of the species Ursus arctos in the Barcelona Zoo. We collected 930 sampling points in each study phase for each of the individuals: The samples were taken in a balanced way at different times of day. We observed a wider range of behavior in the male than the female. With respect to the indicators, we observed statistically significant differences in behavior in both individuals in the 2 study phases. Both individuals showed an increase in vigilance, maintenance, and inactivity when their enclosure was changed. In terms of the subjects' well-being, we considered the percentage of stereotyped behavior within acceptable limits. The percentage of activity observed in the male was very similar to that of individuals of this species in the wild. In terms of the use of space, we observed homogeneity only in the male during the enrichment program. The 2 individuals responded in different ways to the structural enrichment.     

Hunting Patterns,Ban on Baiting,and Harvest Demographics of Brown Bears in Sweden

Abstract We analyzed harvest data to describe hunting patterns and harvest demography of brown bears (Ursus arctos) killed in 3 geographic regions in Sweden during 1981–2004. In addition, we investigated the effects of a ban on baiting, instituted in 2001, and 2 major changes in the quota system: a switch to sex-specific quotas in 1992 and a return to total quotas in 1999. Brown bears (n=887) were harvested specifically by bear hunters and incidentally by moose (Alces alces) hunters. Both hunter categories harvested bears 1) using dogs (37%), 2) by still hunting (30%), 3) with the use of bait (18%), and 4) by stalking (16%). The proportion of bears killed with different harvest methods varied among regions and between bear- and moose-oriented hunters. We found differences between male (52%) and female bears (48%) with respect to the variables that explained age. Moose-oriented hunters using still hunting harvested the youngest male bears. Bears harvested during the first management period (1981–1991) were older and had greater odds of being male than during the subsequent period. It appears that hunters harvesting bears in Sweden are less selective than their North American counterparts, possibly due to differences in the hunting system. When comparing the 4 years immediately prior to the ban on baiting with the 4 years following the ban, we found no differences in average age of harvested bears, sex ratio, or proportion of bears killed with stalking, still hunting, and hunting with dogs, suggesting that the ban on baiting in Sweden had no immediate effect on patterns of brown bear harvest demography and remaining hunting methods. As the demographic and evolutionary side effects of selective harvesting receive growing attention, wildlife managers should be aware that differences in harvest systems between jurisdictions may cause qualitative and quantitative differences in harvest biases. (JOURNAL OF WILDLIFE MANAGEMENT 72(1):79–88; 2008)     

Activity patterns of brown bears (Ursus arctos) in Slovenia and Croatia

In most of Europe, true wilderness areas do not exist and brown bears Ursus arctos generally have to cope with human disturbance and infrastructure. The few studies in Europe that have investigated brown bear activity have demonstrated a predominantly nocturnal and 'shy' behaviour in bears. There is still quite a debate on whether the shy, nocturnal bears of Europe are the result of centuries of persecution by men (genetically fixed trait) or whether hunting and the high disturbance potential in the multi-use landscapes are the driving force (individually learnt trait). We analysed the activity pattern of 16 individual bears monitored for 3372 h between May and October 1982–1998 in the Dinaric Mountains of Slovenia and Croatia. The data were collected via time sampling and basically analysed using two approaches: a general linear model with seasonal component to delineate the most important variables influencing the activity pattern and level and cluster analysis to group bears according to their 24-h activity pattern. Time of day and age were the most important variables predicting activity. Although individual variation in the activity pattern was high among individual bears, in general, yearlings were more diurnal and had a less distinct difference between day- and night-time activity levels than adult bears. Subadults were somewhat intermediate to adults and yearlings. We believe that nocturnal behaviour is most likely driven through negative experiences with humans, giving space for much individual variation. More research is needed to prove the causal relationship of nocturnal behaviour and the degree of disturbance that an individual bear is exposed to.     

A wavelet‐based approach to evaluate the roles of structural and functional landscape heterogeneity in animal space use at multiple scales

The functional relationship between habitat utilization and landscape spatial heterogeneity is fundamental to understanding the spatial nature of animal distribution across scales. Although structural and functional properties of landscape spatial heterogeneity can have different consequences for animal species, few studies have explicitly considered both forms of heterogeneity, partly due to the lack of general methods for direct assessment of scale‐specific associations between variables. We present a wavelet‐based approach to evaluate the roles of structural and functional landscape spatial heterogeneity in animal space use at multiple spatial scales. As a case study, we examined scale‐specific space use patterns of American black bears Ursus americanus in response to structural and functional spatial heterogeneity as well as spatial patterns of vegetation age‐classes in a Canadian boreal forest. We found strong differences in the effects of structural and functional spatial heterogeneity and the scales at which they are associated with the patterns of habitat use by black bears. Functional heterogeneity alone affected space use at 800 and 1600‐m scales, but had significant effects when interacting with structural heterogeneity at 400, 800, and 1600‐m scales. Compared with male bears, female black bears were most sensitive to patterns of forage abundance at intermediate scales, or more specifically, in young and regenerating forests that provide abundant soft mast in boreal forests. Our study highlights the importance of accounting for scale‐dependent properties of (structural and functional) spatial heterogeneity in assessing the ecological effects of landscape components and the effectiveness of the wavelet transform technique in identifying such scale‐specific relationships.     

Nutritional Consequences of Experimentally Introduced Tourism in Brown Bears

Abstract: Although numerous studies have documented behavioral effects of nature-based tourism on wildlife populations, few studies have determined whether behavioral changes translate to effects on individual condition and population health. This issue is currently a concern for wildlife managers in Alaska, USA, and Canada where bear viewing is a rapidly growing industry expanding into previously undisturbed bear habitats. Rather than record observations at long established tourism sites, we experimentally introduced bear viewing into 2 relatively undisturbed brown bear (Ursus arctos) populations in south-central Alaska. We examined the nutritional consequences of behavioral changes induced by the presence and activity of bear viewers for bears feeding on early summer vegetation and late-summer salmon (Oncorhynchus kisutch and O. nerka). We used Global Positioning System collars, monitored food resource availability, and quantified individual resource use and condition for a year prior to and during the introduction of bear viewing. Though bear viewing altered spatiotemporal resource use in all treatments, total resource use declined only when we exposed bears to 24-hour daily human activity. Energy expenditure, indexed as daily travel distances, was significantly higher when bears responded by altering spatial rather than temporal resource use. However, body weight and composition were unaffected by all treatments as bears shifted their foraging to other locations or times. Managers can minimize nutritional impacts of bear-viewing programs by avoiding spatial displacement and providing predictable time periods when bears can access food resources free of human activity. Bears in this study exhibited a high degree of behavioral plasticity, which may be an important factor in identifying flagship species for sustainable ecotourism programs.     

Pattern of space use by female black bears in the White River National Wildlife Refuge,Arkansas, USA

The manner in which space is used by animals may influence several aspects of biology, including the pattern of resource use and intra-specific competition. We monitored 16 radio-collared female black bears (Ursus americanus) for 9,216 radio days during 1993–1995 in the White River National Wildlife Refuge (WRNWR), Arkansas, U.S.A. to investigate space use patterns. Annual home ranges (95% convex polygon) ranged from 2.10 to 11.34 km² with a mean (± SD) size of 4.90 (± 2.09) km² (n = 16). Largest home ranges were occupied by 2 females with yearlings during one year of study. Home ranges among neighbouring bears overlapped considerably. Although bears maintained larger home ranges during summer, the size of home range did not differ among seasons (P > 0.50). Our estimates of home range size for female black bears were smaller than those obtained in a study of the same population during 1979–1982. Because the size of the bear population at WRNWR was substantially smaller (about 130 bears) during 1979–1982 compared to the present population of ≥348 bears, these results suggested that population density and size of female black bear home ranges may be negatively correlated. Conservation implications of density-dependent space use pattern are also discussed.     

Factors Affecting Date of Implantation,Parturition, and Den Entry Estimated from Activity and Body Temperature in Free-Ranging Brown Bears

Knowledge of factors influencing the timing of reproduction is important for animal conservation and management. Brown bears (Ursus arctos) are able to vary the birth date of their cubs in response to their fat stores, but little information is available about the timing of implantation and parturition in free-ranging brown bears. Body temperature and activity of pregnant brown bears is higher during the gestation period than during the rest of hibernation and drops at parturition. We compared mean daily body temperature and activity levels of pregnant and nonpregnant females during preimplantation, gestation, and lactation. Additionally we tested whether age, litter size, primiparity, environmental conditions, and the start of hibernation influence the timing of parturition. The mean date of implantation was 1 December (SD = 12), the mean date of parturition was 26 January (SD = 12), and the mean duration of the gestation period was 56 days (SD = 2). The body temperature of pregnant females was higher during the gestation and lactation periods than that of nonpregnant bears. The body temperature of pregnant females decreased during the gestation period. Activity recordings were also used to determine the date of parturition. The parturition dates calculated with activity and body temperature data did not differ significantly and were the same in 50% of the females. Older females started hibernation earlier. The start of hibernation was earlier during years with favorable environmental conditions. Dates of parturition were later during years with good environmental conditions which was unexpected. We suggest that free-ranging pregnant brown bears in areas with high levels of human activities at the beginning of the denning period, as in our study area, might prioritize investing energy in early denning than in early parturition during years with favorable environmental conditions, as a strategy to prevent disturbances caused by human.     

Seasonal and diel movement patterns of brown bears in a population in southeastern Europe

Most animals concentrate their movement into certain hours of the day depending on drivers such as photoperiod, ambient temperature, inter‐ or intraspecific competition, and predation risk. The main activity periods of many mammal species, especially in human‐dominated landscapes, are commonly set at dusk, dawn, and during nighttime hours. Large carnivores, such as brown bears, often display great flexibility in diel movement patterns throughout their range, and even within populations, striking between individual differences in movement have been demonstrated. Here, we evaluated how seasonality and reproductive class affected diel movement patterns of brown bears of the Dinaric‐Pindos and Carpathian bear populations in Serbia. We analyzed the movement distances and general probability of movement of 13 brown bears (8 males and 5 females) equipped with GPS collars and monitored over 1–3 years. Our analyses revealed that movement distances and probability of bear movement differed between seasons (mating versus hyperphagia) and reproductive classes. Adult males, solitary females, and subadult males showed a crepuscular movement pattern. Compared with other reproductive classes, females with offspring were moving significantly less during crepuscular hours and during the night, particularly during the mating season, suggesting temporal niche partitioning among different reproductive classes. Adult males, solitary females, and in particular subadult males traveled greater hourly distances during the mating season in May‐June than the hyperphagia in July–October. Subadult males significantly decreased their movement from the mating season to hyperphagia, whereas females with offspring exhibited an opposite pattern with almost doubling their movement from the mating to hyperphagia season. Our results provide insights into how seasonality and reproductive class drive intrapopulation differences in movement distances and probability of movement in a recovering, to date little studied, brown bear population in southeastern Europe.     

Efficacy of Bear Deterrent Spray in Alaska

Abstract: We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%), and polar bears (Ursus maritimus; 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears, 20 (28%) black bears, and 2 (3%) polar bears. Red pepper spray stopped bears' undesirable behavior 92% of the time when used on brown bears, 90% for black bears, and 100% for polar bears. Of all persons carrying sprays, 98% were uninjured by bears in close-range encounters. All bear—inflicted injuries (n = 3) associated with defensive spraying involved brown bears and were relatively minor (i.e., no hospitalization required). In 7% (5 of 71) of bear spray incidents, wind was reported to have interfered with spray accuracy, although it reached the bear in all cases. In 14% (10 of 71) of bear spray incidents, users reported the spray having had negative side effects upon themselves, ranging from minor irritation (11%, 8 of 71) to near incapacitation (3%, 2 of 71). Bear spray represents an effective alternative to lethal force and should be considered as an option for personal safety for those recreating and working in bear country. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):640–645; 2008)     

Experimental acoustic telemetry experiment reveals strong site fidelity during the sexual resting period of wild brown meagre,Sciaena umbra

The spatial and temporal patterns exhibited by wild brown meagre, Sciaena umbra, during the sexual resting period were determined using an array of omnidirectional acoustic receivers. In mid‐October 2010, four individuals were tagged using internal acoustic tags and released into their natural habitat. Fish were monitored for up to 70 days within the array of the acoustic receivers. The results provided proof for a variety of aspects of the behavioural biology of this species, including strong site‐fidelity and low levels of mobility. No temporal patterns related to the diel phase were observed, nor was there any significant difference between the means of detection during the day or night. The observations on the use of space also suggest that the brown meagre is a sedentary species with a very limited adult dispersal capacity, spending much of its time within a small home range area (< 1 km²). However, a larger space was used during the night, suggesting an increase in fish activity. This study also provides recommendations for further research on spatial and temporal patterns over lengthy time periods and in different behavioural states such as during the spawning season.     

Patterns of animal–enrichment interaction in captive brown bears

We studied the behavioral responses of three brown bears (Ursus arctos) to different types of enrichment devices to assess the predominant pattern of animal–enrichment interaction (PAI) to each type of enrichment. We assessed the bears' responses to feeding, sensory, and occupational enrichments over nine sessions. Using Pearson's correlation (r) and the coefficient of variation (CV)—we describe four models of PAIs: habituation, increasing, continuous, and fluctuating. The habituation model (r < 0 and p < 0.05; CV (%) > 0) consists of a loss of interest in the device over time and it occurred with the occupational device. The increasing model (r > 0 and p < 0.05; CV (%) > 0) consists of a sustained interest in the device over time and it was not observed for any device of this study. The continuous model (0 > r > 0 and p > 0.05; CV (%) < 100) consists of a consistent and unchanging interaction over time and it occurred with the feeding enrichments used in this study. The fluctuating PAI (0 > r > 0 and p > 0.05; CV (%) ≥ 100) consists of wide oscillations in the degree of interaction over time and we observed this pattern with sensory devices. Review of previous literature supports these classes of PAI, and suggests similar relationships between PAIs and the type of enrichment as we observed in this study.     

Efficacy of firearms for bear deterrence in Alaska

We compiled, summarized, and reviewed 269 incidents of bear–human conflict involving firearms that occurred in Alaska during 1883–2009. Encounters involving brown bears (Ursus arctos; 218 incidents, 81%), black bears (Ursus americanus; 30 incidents, 11%), polar bears (Ursus maritimus; 6 incidents, 2%), and 15 (6%) unidentified species provided insight into firearms success and failure. A total of 444 people and at least 367 bears were involved in these incidents. We found no significant difference in success rates (i.e., success being when the bear was stopped in its aggressive behavior) associated with long guns (76%) and handguns (84%). Moreover, firearm bearers suffered the same injury rates in close encounters with bears whether they used their firearms or not. Bears were killed in 61% (n = 162) of bear–firearms incidents. Additionally, we identified multiple reasons for firearms failing to stop an aggressive bear. Using logistic regression, the best model for predicting a successful outcome for firearm users included species and cohort of bear, human activity at time of encounter, whether or not the bear charged, and if fish or game meat was present. Firearm variables (e.g., type of gun, number of shots) were not useful in predicting outcomes in bear–firearms incidents. Although firearms have failed to protect some users, they are the only deterrent that can lethally stop an aggressive bear. Where firearms have failed to protect people, we identified contributing causes. Our findings suggest that only those proficient in firearms use should rely on them for protection in bear country. © 2012 The Wildlife Society.