Factors influencing the seasonal diet selection by woodland caribou ( Rangifer tarandus tarandus) in boreal forests in Ontario

We used remote video cameras to assess seasonal diet composition of woodland caribou (Rangifer tarandus tarandus (L., 1758)) at three areas across the boreal forest of Ontario. Caribou consume lichens in winter, but we expected they would significantly reduce lichen consumption in favour of higher p...

Full description

Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Thompson, Ian D., Wiebe, Philip A., Mallon, Erin, Rodgers, Arthur R., Fryxell, John M., Baker, James A., Reid, Douglas
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2015
Subjects:
Online Access:http://dx.doi.org/10.1139/cjz-2014-0140
http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjz-2014-0140
http://www.nrcresearchpress.com/doi/pdf/10.1139/cjz-2014-0140
Description
Summary:We used remote video cameras to assess seasonal diet composition of woodland caribou (Rangifer tarandus tarandus (L., 1758)) at three areas across the boreal forest of Ontario. Caribou consume lichens in winter, but we expected they would significantly reduce lichen consumption in favour of higher protein levels in green plants in summer. We sampled videos from 23 caribou, from 2 years, to derive seasonal diet composition. Diet differed among seasons and study areas, except in winter when lichens dominated. Diet breadth doubled from winter to summer, but overlap between seasons was still >60%. Green plants were less commonly eaten than we expected, only three genera were preferred, and few species constituted more than 2% of the diet. Preferred foods varied by land-cover types. Diet differed between managed and unmanaged landscapes but did not result from use of plant species found in successional habitats. Caribou selected a nonoptimal diet in the snow-free seasons, especially with respect to protein, suggesting factors other than nutrition influenced diet choice, and indicating the possibility of bottom-up limitation on production.