Reports of dying voles in Kotzebue area

Observation by Susan Tessier

Several voles have been dying in our area. In talking with others here in Kotzebue, they too have noticed the dead voles.

LEO says:

Thank you for the observation Susan. We reached out to the small rodent science community, and we used a field guide (attached) from the Northwest Territories government, "NWT Guide to Small Mammals", to help with identification. Not sure we nailed the species, but here is what we learned. As far as small mammals, both voles and lemmings are important in Northwest Alaska. Of the voles, there are eight different species that inhabit the northern regions of North America. Six of these are known to inhabit parts of Alaska, and three are species with ranges that overlap with the Northwest Arctic. These include the Northern Red-backed Vole (Clethrionomys rutilus) the Meadow Vole (Microtus pennsylvanicus), and the Tundra Vole (Microtus oeconomus). Given the hint of redish hair in the photo, our guess is that this is a Red-backed vole. See more about both species in the comments below from Jess Steketee. Call out to LEO Network members - please feel free to chime in if you have thoughts or would like to help with identification or related observations.

According to 'Team Vole' there are a variety of ongoing research projects focused on voles and the Arctic ecosystem. See links and sidebar for more information. LEO Network has seen observations about population booms of voles. Also news articles about the relationship between small mammals and a new type of zoonotic virus in Alaska, Boreal Pox. Vole populations generally have been high in the past few years from Southcentral to the Northern parts of Alaska. A die-off could be part of the natural cycle, a signal of food stress, a disease outbreak or something else. We have shared this post with wildlife science, wildlife health and public health professionals, for their information and comment. Lars Flora and Mike Brubaker

Comment by Kimberlee Beckman from Alaska Department of Fish and Game:

Thanks, the Wildlife Disease Surveillance Program hasn’t received any reports of sick or dead voles. We would need carcasses to examine to determine the cause. The State of Alaska has a wildlife disease reporting and submission form at : https://www.adfg.alaska.gov/index.cfm?adfg=disease.reporting. Our contact information is dfg.dwc.vet@alaska.gov

Comment by Jess Steketee, from the University of New Hampshire:

I am on Team Vole project and saw your message. That is very interesting about voles in Kotzebue. Tundra voles (25-80 grams) eat sedges, and leave much more visible evidence on the landscape, like clipped leaves and denuded tussocks, and well defined runways with latrines. Red-backed voles are smaller (17-32 grams), and are more omnivorous, eating berries and seeds. Their effects on vegetation are much less evident even when populations are high. We monitored voles outside of Nome over two years and documented a really massive population swing in red-backed voles and low densities of tundra voles. Typically vole and lemming populations undergo dramatic boom-bust population cycles every 3-5 years; the causes of these cycles are still debated, and are likely due to some combination of weather and/or predators. Often, if winter conditions are good, lemmings (possibly voles to some extent) can breed under the snow and increase their numbers substantially. Once the snow melts, predation can decimate their numbers. Extreme winter conditions could be responsible for a die-off if it occured over winter. We are not monitoring voles and lemmings this year so I don't have a direct comparison, but I shared your message with the small mammal biologist at NEON; they are monitoring small mammals throughout Alaska and might have some insight. It is interesting that this observation was made mid-summer, and makes me wonder if predation rates are high.