The author documented the distribution of polar bears deans in the Arctic National Wildlife Refuge between 1981 and 1992, and observed responses of bears in dens to various human disturbances. Bears were radiocollared during this study period, and showed substantial tolerance for human activities. The purpose of this report was to determine whether the effects of human disturbances resulting from this denning study could be relevant to potential effects of human disturbances resulting from future hydrocarbon development in the 1002 Area of the refuge. The author concludes that the resilence of bears to human disturbance during his research study makes it possible to assume the effects are transferential to future oil field development.
Across the central coast of Alaska’s North Slope, human-polar bear interactions concern both industry and wildlife managers alike. In response to sea ice reductions due to climate change, parturient polar bears (Ursus maritimus) in the Southern Beaufort Sea subpopulation are increasingly accessing coastal topography for suitable denning habitat. Land-denning bears are more susceptible to anthropogenic stressors, chiefly in areas with high levels of energy exploration, extraction, and production. For over 30 years, denning polar bears in the Southern Beaufort Sea subpopulation have been monitored directly or through opportunistic observations. Scientists have opportunistically recorded polar bear responses to aircraft, snow machines, track vehicles, heavy machinery, trucks, dogs, and humans afoot within the denning area. The long-term nature of this work and associated human-bear interaction observations represent a unique dataset that provides insight to wildlife managers into the way polar bears have responded to anthropogenic stimuli in active oil fields. Our objective here is to analyze the different disturbance stimuli at den sites and the associated bear responses. To do so, we subdivided potential stimuli into four groups based on the size, noise levels, and motion of each. Both field notes and video recordings of interactions were analyzed and ranked by response intensity where available. We found significant probabilities for disturbance among all stimulus classes, with aircraft showing the highest potential for initiating den abandonment. However, while all human activities elicited varying degrees of response, the overall response intensity was less than anticipated, even under high-use scenarios. Our data indicate that the current guideline of a 1.6 km (1 mile) buffer zone effectively minimizes disturbance to denning polar bears. These data will provide both wildlife managers and industry with information that can be used to promote polar bear conservation through minimizing disturbance and informing the development of alternative actions for dealing with bears denned near industrial activity.
Sea otters and polar bears are carnivorous marine mammals that still resemble their terrestrial ancestors. Compared with Cetacea (whales and dolphins), Sirenia (dugongs and manatees), and Pinnipedia (seals, sea lions, and walrus), they are less adapted for an aquatic life and the most recently evolved among marine mammals. Sea otters are amphibious but seldom come ashore, and polar bears primarily occur on sea ice or along the shore. When at sea, both species spend most of their time swimming at the surface or making short, shallow dives when foraging or pursuing prey. Indeed, polar bears rarely pursue seals in water. Nevertheless, polar bears are powerful swimmers and will stalk seals from the water. As with many other large carnivores, they are solitary hunters. Although sea otters are gregarious and form aggregations at sea called rafts, they are primarily asocial. Except during mating, the principal interaction among sea otters occurs between a female and offspring during the six-month dependency period. In large carnivores (e.g., wolves and lions) that feed on ungulates, sociality and cooperation are favored because of the need to capture large prey and defend carcasses. Polar bears, which are the largest terrestrial carnivore, are solitary hunters of seals and are neither gregarious nor social. Males and females briefly associate during courtship and mating. During this time, males aggressively compete for females. At other times, males generally avoid each other except for aggregations of males that form while summering on land, and females with cubs avoid males, which are known for infanticide. As with sea otters, the interaction of polar bears outside of mating occurs between a female and her offspring during the 2-3 year dependency period. This interaction is critically important when altricial cubs are born in the winter den. This book provides new insight into the ethology and behavioral ecology of sea otters and polar bears. Each chapter reviews the discoveries of previous studies and integrates recent research using new techniques and technology. The authors also address historic and current anthropogenic challenges for their survival as climate change alters entire marine ecosystems.
These proceedings provide an overview of the ongoing research and management activities on polar bears in the circumpolar arctic. Together with the previous 12 proceedings, they provide an historic record of international efforts in protecting polar bears from over-harvest and document more recent concerns of threats arising from increased human activities in both the Arctic and in regions far beyond the realm of polar bears. More proactive management is needed to address limitations in the knowledge of population dynamics. New information indicates that the greatest future challenges to polar bear conservation may be ecological change in the Arctic due to climate change and pollution. The complex, global nature of the issues requires international cooperation and development of diverse, new approaches to address them.
In Arctic Canada, Hudson Bay is a site of great exploration history, aboriginal culture, and a vast marine wilderness supporting large populations of marine mammals and birds. These include some of the most iconic Arctic animals like beluga, narwhal, bowhead whales, and polar bears. Due to the challenges of conducting field research in this region, some of the mysteries of where these animals move, and how they are able to survive in such seemingly inhospitable, ice-choked habitats are just now being unlocked. For example, are polar bears being replaced by killer whales? This new information could not be more salient, as the Hudson Bay Region is undergoing rapid environmental change due to global warming, as well as increased pressures from industrial development interests. A Little Less Arctic brings together some of the world’s leading Arctic scientists to present the current state of knowledge on the physical and biological characteristics of Hudson Bay.
