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dc.contributor.advisorChairperson, Graduate Committee: Scott Creel.en
dc.contributor.authorChristianson, David Alan.en
dc.date.accessioned2013-06-25T18:37:35Z
dc.date.available2013-06-25T18:37:35Z
dc.date.issued2008en
dc.identifier.urihttps://scholarworks.montana.edu/xmlui/handle/1/1076
dc.description.abstractUntil recently, predators have been though to regulate prey primarily through direct predation, in ecosystems where top down effects have been shown to be important. However, experiments and recent empirical observations show that the costs of antipredator responses in individuals that successfully avoid predation can exert equal or larger driving forces on population dynamics than the numerical effect of direct predation. Such a mechanism has not been explored in a large terrestrial vertebrate. I explored the antipredator responses of elk (Cervus elaphus) to wolves (Canis lupus) in the Upper Gallatin Canyon of southwest Montana, USA, December through May in the winters of 2003-2006. First I reviewed elk winter diet studies to understand what drives elk foraging behavior. Next I modeled the consequences of diet shifts in grazing and browsing on mass dynamics in wintering female elk. I also developed a new nutritional index, fecal chlorophyll, that I used primarily between winter and spring periods of nutrition as foraging constraints (and costs of antipredator response) would be quite different between these two periods. Specifically, I measured foraging behavior, diet selection, and nutrient balance in wintering elk and monitored daily predation risk as wolves moved naturally, in and out of four creek drainages that formed the primary winter range. Elk showed great sensitivity to fine-scale descriptions of wolf predation risk in nearly every response variable. In particular, adult female elk increased browsing on woody stems, sagebrush, and confers while adult males showed the opposition response and increased grazing on days when wolves were present in the same drainage. This work implies that predator may in fact play a large role in ecosystems including ecosystems where predators were deemed non-influential and bottom up effects important.en
dc.language.isoengen
dc.publisherMontana State University - Bozeman, College of Agricultureen
dc.subject.lcshElk Behavior.en
dc.subject.lcshWolves.en
dc.subject.lcshPredation (Biology)en
dc.subject.lcshElk Feeding and feeds.en
dc.titleRisk effects in Elk (Cervus elaphus) : behavioral and nutritional responses to wolves and environmental conditions
dc.typeDissertation
dc.rights.holderCopyright David Alan Christianson 2008en
thesis.catalog.ckey1327458en
thesis.degree.committeemembersMembers, Graduate Committee: Peter Gogan; Bruce Maxwell; Billie Keransen
thesis.degree.departmentLand Resources & Environmental Sciences.en
thesis.degree.genreDissertationen
thesis.degree.namePhDen
thesis.format.extentfirstpage1en
thesis.format.extentlastpage183en
mus.identifier.categoryLife Sciences & Earth Sciences
mus.relation.departmentLand Resources & Environmental Sciences.en_US
mus.relation.universityMontana State University - Bozemanen_US


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