Draft
Due to their environment, caribou have developed adaptions and methods for efficiency during the warm months as well as for warmth during the cold months. The body composition of caribou varies highly with the seasons. [1]
The environmental variations play a large part in their nutrition, as winter nutrition is crucial to adult and neonatal survival rates[2]. Lichens are a staple during the winter months as they’re a readily available food source, which reduces the reliance on stored body reserves. Despite lichens being a crucial part in the diet of all caribou, they are less prevalent in the diet of pregnant caribou compared to non-pregnant individuals. This is in part because although lichens are high in carbohydrates, they are lacking in protein that vascular plants provide[3]. It was shown that the amount of lichen in a diet decreased with increasing latitude. Nutritional stress is highest where lichen abundance was low. Lichen abundance is more closely related to adult survivorship than pregnancy itself.
Breeding females have more body mass than nonbreeding females between the months of March and September with a difference of about 10kg. However, in the November-December, nonbreeding females have more body mass than the breeding females. Body masses of both breeding and non-breeding females peaked in September. During the March-April reading, breeding females have more fat mass than the nonbreeding females with a difference of almost 3kg. After this however, every reading afterwards showed that the nonbreeding females had more fat mass than the breeding females.[4]
I think it would be more effective to make overall statements about caribou instead of referring to specific studies that have been done particularly in the second paragraph. I also think you could tie all of the information together better - RAS — Preceding unsigned comment added by Rachelsmiley (talk • contribs) 17:55, 27 April 2016 (UTC)
Updated Draft
Caribou have developed adaptions for optimal metabolic efficiency during warm months as well as for during cold months.[5] The body composition of caribou varies highly with the seasons. Of particular interest is the body composition and diet of breeding and non-breeding females between seasons. Breeding females have more body mass than non-breeding females between the months of March and September with a difference of around 10 kg more than non-breeding females. From November to December, non-breeding females have more body mass than breeding females as non-breeding females were able to focus their energies towards storage during colder months rather than lactation and reproduction. Body masses of both breeding and non-breeding females peaked in September. During the months of March through April, breeding females have more fat mass than the nonbreeding females with a difference of almost 3 kg. After this however, nonbreeding females on average have a higher fat mass than the breeding females.[6]
The environmental variations play a large part in caribou nutrition, as winter nutrition is crucial to adult and neonatal survival rates.[7] Lichens are a staple during the winter months as they’re a readily available food source, which reduces the reliance on stored body reserves.[8] Lichens are a crucial part of the caribou diet, however they are less prevalent in the diet of pregnant caribou compared to non-pregnant individuals. The amount of lichen in a diet is found more in non-pregnant adult diets than pregnant individuals due to the lack of nutritional value. Although lichens are high in carbohydrates, they are lacking in essential proteins that vascular plants provide. The amount of lichen in a diet decreases in latitude that results in nutritional stress being higher in areas with low lichen abundance.[9]
@EWool101: Emilee, thanks for commenting on Rachel's Mule deer contribution!
Rico.schultz (talk) 16:26, 29 April 2016 (UTC)
References
Karasov, W.H. and Martinez del Rio, C. 2007. The Chemistry and Biology of Food in Physiological Ecology: How Animals Process Energy, Nutrients, and Toxins (pp. 49-108).
Wilmer, Pat; Stone, Graham; Johnston, Ian (2009). Environmental Physiology of Animals. Wiley. pp. 645-663. ISBN 9781405107242.
Joly, K., Wasser, S. K., & Booth, R. 2015. Non-invasive assessment of the interrelationships of diet, pregnancy rate, group composition, and physiological and nutritional stress of barren-ground caribou in late winter. PLOS ONE, 10(6).
Allaye Chan-McLeod AC, White RG, Russell DE. 1999. Comparative body composition strategies of breeding and nonbreeding female caribou. Canadian Journal of Zoology. 77(12): 1901-1907
Karasov, W.H. and Martinez del Rio, C. 2007. The Chemistry and Biology of Food in Physiological Ecology: How Animals Process Energy, Nutrients, and Toxins (pp. 49-108).
Allaye Chan-McLeod AC, White RG, Russell DE. 1999. Comparative body composition strategies of breeding and nonbreeding female caribou. Canadian Journal of Zoology. 77(12): 1901-1907
Wilmer, Pat; Stone, Graham; Johnston, Ian (2009). Environmental Physiology of Animals. Wiley. pp. 645-663. ISBN 9781405107242.
Allaye Chan-McLeod AC, White RG, Russell DE. 1999. Comparative body composition strategies of breeding and nonbreeding female caribou. Canadian Journal of Zoology. 77(12): 1901-1907
Joly, K., Wasser, S. K., & Booth, R. 2015. Non-invasive assessment of the interrelationships of diet, pregnancy rate, group composition, and physiological and nutritional stress of barren-ground caribou in late winter. PLOS ONE, 10(6).