Examining the influences of changes in snowpack structure on the declining Bathurst caribou herd in the Northwest Territories.
Examining the influences of changes in snowpack structure on the declining Bathurst caribou herd in the Northwest Territories.
Abstract ID#: 35850
English Abstract:
Over the past 15 years the Bathurst Caribou herd in the Northwest Territories has undergone a dramatic 96% decrease in population. The objective of this research is to determine if snowpack conditions in the winter foraging grounds of the Bathurst herd have changed over long periods of time in response to a warming climate and, in response to this, if the frequency of ice lens formation in the snowpack has changed over the past 20 years. Changes in snowpack characteristics such as dpeth, and increases in ice lenses may provide physiological challenges to caribou as for 6-7 months of the year their primary food source –lichen- lays at the base of the annual snowpack. To explore this idea remote sensing tools are employed. The Globsnow database is utilized to quantify changes in snowpack water equivalent (SWE) and assess the probability of ice lens formation especially during the fall and spring of sequential years between the late 1990’s to present time. The snowpack water equivalent data is derived from a combination of SSM/I satellite data (passive microwave emissions at 37 GHz and 19 GHz) and local weather station data. Over the past several years the Environment and Natural Resources Ministry (Wildlife Division) of the Government of the Northwest Territories has monitored the movement of approximately 20 caribou of the Bathurst herd outfitted with satellite collars. Assuming the movement of these individuals is representative of the pattern of movement of the non-collared herd it is possible to relate caribou spatial movement with respect to snowpack conditions on a daily basis. To assess whether snowpack conditions impact the distribution of the collared caribou specific pixels within the fall to early spring foraging habitat have been selected for long term evaluation and compared to caribou occurrence. Areas previously burned by forest fires are included in the data evaluation.