Wolverines live in harsh conditions; they range over large areas of cold mountainous low-productivity habitat with persistent1 snow. The paper suggests wolverines take advantage of the crevices2(裂缝) and boulders3(岩石) of the mountainous terrain4, as well as the snow cover to cache(躲藏) and "refrigerate" food sources such as elk5(麋鹿) , caribou6(北美驯鹿) , moose(驼鹿) and mountain goat carrion7, ground squirrels and other food collected during more plentiful8 times of year. These cold, structured chambers9 provide protection of the food supply from scavengers(食腐动物) , insects and bacteria. In addition, the refrigerated caches increase the predictability of available food resources, reduce the energy spent by females searching for food while in lactation(哺乳期) phase, and decrease the time mothers spend away from cubs10.
The paper appears in the current edition of the Journal of Mammalogy and was co-authored by Robert M. Inman of WCS, Audrey J. Magoun of Wildlife Research and Management, Jens Persson of the Swedish University of Agricultural Sciences, and Jenny Mattisson of the Norwegian Institute for Nature Research.
"People don't normally think of insects and microbes as being in competition for food with wolverines," said lead author Robert Inman of the Wildlife Conservation Society's North America Program. "But in fact, bacteria will devour11(吞食,毁灭) an unprotected food source if that source is available."
Through an extensive literary review, the authors noted12 that wolverine reproduction is confined to a brief period of the year, and the lactation phase in females (February through April) corresponds to a period of low availability of food resources. Wolverines, which are opportunistic foragers, have adapted by amassing13 food caches during the preceding winter months when food is more readily available. Without the cached food supply or an unforeseen alternative (such as a winter-killed ungulate), early litter loss occurs.
Inman said, "Understanding why and how wolverines exist where they do and the various adaptations they have evolved to eke14 out a living will better inform population management strategies and conservation of the species."
Climate change will play a key role in management planning for the conservation of wolverines, the authors say.
In a study published in 2010, wolverine biologists demonstrated a relationship between the areas where wolverines exist (their distribution) and persistent snow cover. The first theory advanced was that wolverines must have deep snow available in springtime so that they can give birth to their small cubs in a warm, secure den15. The newly released study suggests that other factors related to climate and snow pack, such as competition for food, may also be involved in explaining the limits to wolverine distribution.