• Effects of diet quality and quantity on caribou and reindeer (Rangifer tarandus)

      Thompson, Daniel Paul; Barboza, Perry S.; Parker, Katherine L.; Kielland, Knut; Hundertmark, Kris J. (2013-05)
      Caribou and reindeer (Rangifer tarandus) encounter natural and anthropogenic disturbances across the landscape. In late winter, Rangifer encounter acute food from disturbances such as icing events. Furthermore, as shrubs expand into the Arctic tundra, the proportion of low quality browse may increase in the summer diet of Rangifer. This study evaluated how Rangifer tolerate 1) fluctuations in food quantity in late winter and 2) changes in forage quality over the summer. Rangifer can compensate for food shortages by increasing intake after restriction, which would allow animals to restore body mass quickly during migration. High body fat reserves increase the tolerance of food shortages. During the summer, Rangifer can consume exclusively browse to meet daily energy requirements; however, low nitrogen supply and high toxin load would require the use of alternative forages to supplement nitrogen and reduce toxins.