Description
During the early 1900s the Fortymile Caribou herd once ranged from near Tanana, Alaska to Lake Laberge, Yukon Territory. After declining to a population low of about 6,500 in 1973, the Fortymile herd increased slowly to 22,000 in 1992 and has since more than doubled in numbers (51,000 in 2010). The herd range is expanding into areas used historically (most notably with an abrupt movement of most of the herd into Yukon Territory in fall of 2013). However, the herd may be showing signs of nutritional stress (Boertje et al 2012), including reduced birth rates, and lower 4 month old calf weights. State of Alaska, Department of Fish and Game (ADFG), the Yukon Governmentâ¿¿s Department of Environment (YE), National Park Service (NPS), and the Bureau of Land Management, have long been cooperating in management of the Fortymile Caribou Herd, including management of subsistence harvest. With the implementation of a cooperative program of Fortymile caribou herd monitoring with GPS radiocollars (begun in 2010), high quality animal location data are available to begin to address important management questions. Additional information, such as lichen cover maps being developed for the entire herd range, and remote sensing products (e.g., snow cover/depth/quality) from the NASA ABoVE â¿¿Animals on the Moveâ¿¿ project, will aid in describing and predicting caribou habitat use. The recent en masse movement of Fortymile caribou into the Yukon during the winter of 2013-14 has highlighted the need for international management of the Fortymile Caribou Herd and consideration of habitat across the entire historical range of the herd. Management concerns include: potential nutritional limitations experienced by the herd, potential industrial development (including plans for several large mines in the Yukon), land use and conservation planning efforts, effects of fire and climate change on caribou habitats. The recent availability of high quality radio-collar relocation data (through a cooperative monitoring program) allows for a timely investigation of Fortymile caribou habitat use that will assist in addressing these and other management concerns in Alaska and the Yukon. The Fortymile Caribou Herd is already formally part of the â¿¿Animals on the Moveâ¿¿ NASA ABoVE project via partnerships with ADFG, YE and BLM. The â¿¿Animals on the Moveâ¿¿ partnership provides opportunities to leverage ongoing comparative work on seasonal habitat use, resource selection and nutritional ecology (via remote sensing) across multiple populations of caribou in Alaska and the Yukon. Understanding how the Fortymile herd is using the landscape and where it may use it in the future (across all seasons) is of direct management interest.