Foxes, and how are they doing?
The swift fox is a small carnivore that weighs about 2.5 kg, eats mainly mice and voles, is lighter than most house cats, is half the size of a red fox, and got its name because it can run faster than 60 km / hr! It went extinct in Canada by 1938, but reintroduction releases spanning from 1983-1997 re-established a small population.
We conducted population surveys in the winters of 1996/97, 2000/01, and 2005/06. While the first was only in Canada the other two included Montana where some foxes had dispersed. In Canada the population grew until 2001, after which it seemed to stay the same. The results triggered an improvement in the national conservation status of the species from “Endangered” to “Threatened” in 2012. In Montana, the population was still expanding in 2006.
Where are we now?
There has been no population–wide survey conducted across their range since 2006. Threats to swift foxes continue to exist so we want to determine if the population will be able to sustain its status, or if positive/negative changes in abundance, distribution, or composition have occurred.
Field work spanning from 2013-2015 was initiated last winter which includes camera-trap monitoring that spans 2013-2015 and live trapping that spans the winter of 2014-2015. Starting October 31,an area of 21,742 km2 (237 townships) including Canadian areas spanning roughly from Manyberries, Alberta to the east block of Grasslands National Park Saskatchewan will be surveyed. Montana Fish, Wildlife and Parks will be surveying their relevant area at the same time.
Camera-trapping: A non-invasive method of re-sampling where a movement-sensor camera is set near a small wooden post that is put in the ground and scented with fish oil.
Live-trapping: a method where a set of six box traps are set, near the centre of each township, 1 km apart for three consecutive nights. The traps have been custom-lined to prevent any injuries to foxes. Traps are checked every six hours at night and closed during the day. Upon capture, the foxes are removed from the trap with a denim handling bag, weighed, sexed, tattooed in the ear, aged by looking at teeth and subsequently released.
– Excerpts from 2014/205 Canada/Montana Swift Fox Population Survey brochure created by Cynthia Moehrenschlager