Kristin S. Simac

Detecting Denning Polar Bears with Forward-Looking Infrared (FLIR) Imagery

Abstract Polar bears give birth in snow dens in midwinter and remain in dens until early spring. The survival and development of cubs is dependent on a stable environment within the maternal den. To mitigate potential disruption of polar bear denning by existing and proposed petroleum activities, we used forward-looking infrared (FLIR) viewing to try to detect heat rising from dens. We flew transects over dens of radio-collared females with FLIR imager–equipped aircraft, recorded weather conditions at each observation, and noted whether the den was detected. We surveyed 23 dens on 67 occasions (1 to 7 times each). Nine dens were always detected, and 10 dens visited more than once were detected on some flights but not on others. Four dens were never detected (17 percent), but three of those were visited only under marginal conditions. The odds of detecting a den were 4.8 times greater when airborne moisture (snow, blowing snow, fog, etc.) was absent than when it was present, and they increased 3-fold for every 1°C increase in temperature–dew point spread. The estimated probability of detecting dens in sunlight was 0. Data suggested that FLIR surveys conducted during optimal conditions for detection can produce detection rates approaching 90 percent and thus can be an important management and mitigation tool.

Effects of capturing and collaring on polar bears: findings from long-term research on the southern Beaufort Sea population

Abstract Context. The potential for research methods to affect wildlife is an increasing concern among both scientists and the public. This topic has a particular urgency for polar bears because additional research is needed to monitor and understand population responses to rapid loss of sea ice habitat. Aims. This study used data collected from polar bears sampled in the Alaska portion of the southern Beaufort Sea to investigate the potential for capture to adversely affect behaviour and vital rates. We evaluated the extent to which capture, collaring and handling may influence activity and movement days to weeks post-capture, and body mass, body condition, reproduction and survival over 6 months or more. Methods. We compared post-capture activity and movement rates, and relationships between prior capture history and body mass, body condition and reproductive success. We also summarised data on capture-related mortality. Key results. Individual-based estimates of activity and movement rates reached near-normal levels within 2–3 days and fully normal levels within 5 days post-capture. Models of activity and movement rates among all bears had poor fit, but suggested potential for prolonged, lower-level rate reductions. Repeated captures was not related to negative effects on body condition, reproduction or cub growth or survival. Capture-related mortality was substantially reduced after 1986, when immobilisation drugs were changed, with only 3 mortalities in 2517 captures from 1987–2013. Conclusions. Polar bears in the southern Beaufort Sea exhibited the greatest reductions in activity and movement rates 3.5 days post-capture. These shorter-term, post-capture effects do not appear to have translated into any long-term effects on body condition, reproduction, or cub survival. Additionally, collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival. Implications. This study provides empirical evidence that current capture-based research methods do not have long-term implications, and are not contributing to observed changes in body condition, reproduction or survival in the southern Beaufort Sea. Continued refinement of capture protocols, such as the use of low-impact dart rifles and reversible drug combinations, might improve polar bear response to capture and abate short-term reductions in activity and movement post-capture.

Serum Urea and Creatinine Levels of Spring-caught Polar Bears (Ursus maritimus) in the Southern Beaufort Sea, 1983-2016, and Chukchi Sea, 1987-1993

These data are serum urea nitrogen and creatinine levels for polar bears captured in the southern Beaufort Sea 1983-2016 and the Chukchi Sea 1987-1993. The dataset includes relevant information about the bears that were captured including the latitude and longitude of their capture location, capture date, age class and sex, the age and number of cubs accompanying an adult female, and whether the bear denned during the previous winter or exhibited signs of being engaged in mating behavior at the time of or just prior to capture.

Human–Polar Bear Interactions in a Changing Arctic: Existing and Emerging Concerns

The behavior and sociality of polar bears (Ursus maritimus) have been shaped by evolved preferences for sea ice habitat and preying on marine mammals. However, human behavior is causing changes to the Arctic marine ecosystem through the influence of greenhouse gas emissions that drive long-term change in ecosystem processes and via the presence of in situ stressors associated with increasing human activities. These changes are making it more difficult for polar bears to reliably use their traditional habitats and maintain fitness. Here, we provide an overview of how human activities in the Arctic are likely to change a polar bear’s behavior and to influence their resilience to environmental change. Developing a more thorough understanding of polar bear behavior and their capacity for flexibility in response to anthropogenic disturbances and subsequent mitigations may lead to successful near-term management interventions.