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Abstract
The principle of energy allocation states that individuals should attempt to maximize fitness by allocating resources optimally among growth, maintenance, and reproduction. Such allocation may result in trade-offs between survival and reproduction, or between current and future reproduction. We used a marked population of North American elk (
Cervus elaphus) to determine how energetic costs of reproduction in the current year affect survival and reproduction in the subsequent year. Using a multistate mark-recapture model we examined the influence of individual and environmental variation on trade-offs between these 2 life-history traits. We observed no difference in survival probabilities between pregnant and nonpregnant individuals or as a function of recruiting an offspring. Nonetheless, there was a negative effect of recruiting an offspring in the current year on becoming pregnant the following year. Increased body condition, and higher precipitation, contributed to greater probabilities of becoming pregnant in a particular year regardless of reproductive state and previous recruitment. Costs associated with reproduction led to a reduced probability of future reproduction rather than a reduction in survival. These findings are consistent with risk-sensitive reproductive allocation, where adult survival is maintained through variation in reproductive effort resulting in high and stable adult survival and more-variable reproduction.
Keywords
Cervus elaphus,
fitness,
life-history strategy,
multistate mark-recapture technique,
recruitment,
reproductive costs,
resource allocation,
risk-sensitivity,
transition,
probability,
ungulates
Citation
Morano, Sabrina; Stewart, Kelley M.; Sedinger, James S.; Nicolai, Christopher A.; Vavra, Martin. 2013. Life-history strategies of North American elk: trade-offs associated with reproduction and survival. Journal of Mammalogy, Vol. 94(1): 11 pages.: 162-172.
