Reliability of blood parameters to assess the nutritional status of caribou

Abstract

Total body fat reserves and 13 blood parameters were assessed from 58 female caribou. Animals were sampled in autumn and in spring from the George River caribou herd, northern Quebec and Labrador. Most blood constituents showed a remarkable homeostasis even though fat reserves ranged from 1.6 to 19.3% of the body mass. Total proteins versus fat content yielded a positive relationship, yet with a poor predictive power (r² = 0.36). The lack of response in most blood parameters might be ascribable to small variations in diet among individual caribou. These variations in diet, although possibly small, may have a cumulative effect on fat reserve dynamics. Overall, we did not identify a set of blood parameters that could adequately reflect nutritional status of caribou. The limitations of blood parameters as indicators of the general nutritional status of caribou are discussed.