Contact Us
  • Wendy Loya
    Arctic LCC Coordinator

    U.S. Fish & Wildlife Service
    1011 East Tudor Road
    Anchorage, Alaska 99503
    (907) 786-3532
  • Paul Leonard
    Arctic LCC Science Coordinator

    U.S. Fish & Wildlife Service
    101 12th Avenue, Rm. 216
    Fairbanks, Alaska 99701
    (907) 456-0445
  • Josh Bradley
    Arctic LCC Data Manager

    U.S. Fish & Wildlife Service
    101 12th Avenue, Rm. 216
    Fairbanks, Alaska 99701
    (907) 455-1847

SnowDens-3D Decision Support Tool

SnowDens-3D is a snowdrift den-habitat decision-support tool based on the recently developed polar bear snowdrift den habitat mapping tool (Liston et al., 2016). The decision-support software ingests available topographic and weather data, and provides output maps of high-probability den locations, for any year of interest, including the current year. The software is available to end-users interested in polar bear management activities, and is available to help “fine tune” habitat search parameters and locations when managers are looking for likely denning areas.

Polar bears are protected under provisions of the 1972 Marine Mammal Protection Act and were listed as a threatened species in 2008 under the Endangered Species Act (ESA). Protective measures implemented within this legal framework include efforts to avoid disturbing maternal polar bear dens. This is challenging, however, because dens are difficult to detect under the snow surface. It is in the interests of both bear conservation and cost-containment for industry to obtain the most accurate predictions possible of potential polar bear den locations.


Screenshot of the main SnowDens-3D screen. Click the image to zoom in.

Why SnowDens-3D?

Historically, available den habitat models have been based primarily on the presence of topographic features capable of capturing drifting snow. In any given season, however, the availability and precise location of snowdrifts of sufficient size to accommodate a bear den depends on the antecedent snowfall and wind conditions, and these vary from one year to the next. Thus, suitable topography is a necessary pre-condition, but is not sufficient to accurately predict potential den sites in a given year.

To satisfy the requirements of agency and industry managers what is needed is a user- friendly decision-support tool that takes into account the current fall and early-winter meteorological conditions, and provides den habitat information that can be used to guide polar bear management and avoidance decisions for the rest of that winter after the bears have entered their dens.