monitoring spatial and temporal distribution of polar bear maternity dens in Svalbard

Sea ice distribution has been shown to influence the number of females that reproduce locally in Svalbard. At Hopen, few females den in winters if arrival of sea ice is late (e.g. in December).
The project aim at explaining how sea ice influence denning of polar bears both within years (the distribution of dens and how this fit with sea ice conditions around the different islands), and temporally over years (e.g. if the number of females denning varies both locally and on a larger scale).

The main motivation for this monitoring program is to study how climate might affect reproduction and thus population growth in Svalbard, and not least to be better able to predict how future changes in sea ice conditions will influence the population.

The survey is done from helicopter in spring.
dens are located from air, frequently using tracks as clues to locate den openings.
Telemetry data is also used to locate females that den, and the location. In spring 2009 a ground survey at Kongsøya will be used to evaluate how efficient the helicopter air survey is to estimate the number of dens in an area.

Most dens in Svalbard are located within 5 main areas, making it possible to perform a den study with reasonable effort. Norwegian POlar Institute has already a data base with a few hundred den observations from those areas that can be included in data analyses.

The den surveys are planned to be performed every spring with a coverage that includes the main denning areas.