Habitat specificity among ground squirrel populations at multiple spatial scales ...

• Main Author: Werner, Jeffery Ross
• Format: Text
• Language: English
• Published: University of British Columbia 2017
• Subjects: Arctic ground squirrel; Arctic; Urocitellus parryii; Yukon
• Online Access: https://dx.doi.org/10.14288/1.0340522; https://doi.library.ubc.ca/10.14288/1.0340522

The arctic ground squirrel (Urocitellus parryii; AGS) comprised 17% of the herbivore biomass in the Yukon boreal forest during the summer months from 1987 to 1996 and accounted for 23% of the energy flow at the herbivore level. By 2000 these ground squirrel populations had collapsed to nearly zero and today they comprise ~1% of the herbivore biomass in this zone. Most forest populations (~95%) are extirpated, whereas only 65% of low-elevation meadow populations are extirpated. AGS remain abundant in alpine (93% occupancy) and in human altered habitats (97% occupancy). During spring, postpartum females in forests weighed less and were in poorer condition than females in meadows. However, by onset of hibernation, forest squirrels had reached parity with meadow squirrels in mass and condition. For squirrels in formerly occupied boreal forests a) poor spring body condition likely decreased reproductive success, and b) achieving compensatory growth, via increased foraging, may result in higher predation risk. ...