Friday, March 25, 2016

Tracking Meadow Voles

Meadow Vole - Microtus pennsylvanicus

Meadow Voles have the largest range of any North American vole and can be found in every province and in the Arctic.

Meadow voles do not hibernate and are active all year round.

The photo below shows the bounding gait of a Meadow Vole in the snow. The tail is responsible for the center line between the prints. 

Winter nests are usually created in grassy areas on the ground and under a layer of snow. Burrows are connected to grassy runways which allow the vole access to feeding sites.

The photo below shows a snow tunnel created by a vole on an ice surface over a shallow portion of the Elbow River. The tunnel started by the land edge where tussocks of marsh grass served as the burrow. The vole likely abandoned this runway when continued ice implied that a feeding site was not close.

Below is a photo of a typical Meadow Vole runway through yard grass. The runways were created during the winter under the snow and are conspicuous once the snow melts in the spring.

In the photo below, the runway from the upper left leads to a nesting area towards the right.

Summer nests are similarly built as shallow burrows, often under debris, and are connected to a network of runways through the grass. 

Breeding starts in early spring while the burrows are still covered in snow and continues until autumn. Females are sexually mature as early as 25 days of age. Gestation last 21 days. The average litter is 4 to 6 infant voles. There are two to four litters a year in the wild. In captivity a female who mates immediately after every litter might give birth up to 17 times a year. Theoretically, with enough food and without any predation, illness, or injury, a pair of Meadow Voles could produce a million descendants in one year!!

Naughton D. The Natural History of Canadian Mammals. University of Toronto Press. 2012. 

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