Comparison of energy metabolism in relation to daily activity and milk consumption by caribou and muskox neonates
Growth rates, milk intake, activity patterns, and daily energy expenditures of neonatal caribou (Rangifer tarandus granti) and muskoxen (Ovibos moschatus) were compared over a 100-day period to examine the strategies of two arctic follower species with different life history patterns. Relative growt...
| Published in: | Canadian Journal of Zoology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1990
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z90-015 http://www.nrcresearchpress.com/doi/pdf/10.1139/z90-015 |
| Summary: | Growth rates, milk intake, activity patterns, and daily energy expenditures of neonatal caribou (Rangifer tarandus granti) and muskoxen (Ovibos moschatus) were compared over a 100-day period to examine the strategies of two arctic follower species with different life history patterns. Relative growth rates, which reflected milk protein and energy intake, were higher for caribou during the 1st week of age and after 75 days of age than for muskox calves. Daily energy expenditures, estimated with the doubly labeled water technique, were significantly greater for caribou neonates than for muskoxen. Adult female caribou lost body weight during the first 2–3 weeks of lactation, but then increased 15% above postpartum weights during the summer period. Adult female muskoxen maintained weight, with no significant changes throughout the summer. Caribou milk was higher in protein, dry matter, and energy content than that of muskoxen. |
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