This project was funded through a co-operative agreement between the Alaska Center for Conservation Science – Zoology Program and The Alaska Department of Fish and Game – Threatened, Endangered and Diversity Program
During summer of 2015, the zoology program conducted baseline surveys for small mammal taxa and habitat along the Colville River, a historically under-sampled region. The goals of the study were to determine (a) what species/subspecies are currently present along the Colville River, (b) what is the distribution of each taxon, and (c) what types of habitat are currently being used by each taxon. In addition, we investigated the northern range extent for the Alaska tiny shrew and little brown myotis (species of high interest) and contributed samples to the University of Alaska Museum of the North collection.
Once habitat analysis is complete, we will provide a detailed report of survey methods and results. We are also working on a peer-reviewed publication describing our findings.
The Colville River runs 560 km east from the De Long Mountains, along the Brooks Foothills and into the Beaufort Sea. Historically, the majority of the wildlife studies in the area and on the North Slope have focused mainly on large, fur-bearing mammals such as caribou, brown bears, and muskox. To our knowledge, there are no recent surveys on the status or habitat use of small mammals in the Brooks Foothills. Small mammal surveys were conducted at 5 sites along a 250 mile section of the Colville River between the confluence of the Kiligwa River and Umiat from 10 June to 26 June, 2015.
According to range maps and distribution models developed for the Alaska Gap Analysis Project, the following small mammal species are expected to occur in the Brooks foothills: Nearctic collared lemming (Dicrostonyx groenlandicus), Nearctic brown lemming (Lemmus trimucronatus), singing vole (Microtus miurus), root vole (Microtus oeconomus), meadow vole (Microtus pennsylvanicus), taiga vole (Microtus xanthoghathus), northern red-backed vole (Myodes rutilus), masked shrew (Sorex cinereus), dusky shrew (Sorex monticulous), tundra shrew (Sorex ugyunak), and Alaska tiny shrew (Sorex yukonensis).
At each survey site, we set up three trapline “loops”, each placed in a habitat type distinct from the others (e.g. riparian, low shrub tundra, tussock tundra, etc.). Each loop was approximately 1 kilometer in length and consisted of 100 trap placements approximately 10 meters apart. We used three different trap types (Sherman, pit-fall, and museum special) to diversify our efforts and increase our capture success across species. Traps at each survey site were set for two nights and one day, totaling 600 trap-nights per site. In addition, trail cameras and echolocation recorders were placed to observe medium to large mammals and bats, respectively. We captured and identified to species level 176 individuals. Morphometric measurements were recorded for each capture, including mass, body length, tail length, ear length, and hind foot length. Captures were distributed among a total of five species.
This project was funded through the Alaska Department of Fish and Game: Threatened, Endangered, and Diversity Species Program.