American Society of Naturalists

A membership society whose goal is to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences.

“The influence of early reproductive success on longevity and late reproductive success in an alpine ungulate”

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Andrea Panagakis, Sandra Hamel, and Steeve D. Côté

Can mountain goats ‘have it all’?

Alpine icons: mountain goats (<i>Oreamnos americanus</i>) at Caw Ridge, Alberta, Canada.<br />(Photo: Edouard Bélanger 2014)
Alpine icons: mountain goats (Oreamnos americanus) at Caw Ridge, Alberta, Canada.
(Photo: Edouard Bélanger 2014)

There’s an old Rolling Stones song that goes, “You can’t always get what you want,” suggesting that compromises are a part of life. Researchers from Université Laval in Québec, Canada, wanted to investigate whether this was the case with adult female mountain goats, an iconic alpine species found in North America. Mountain goats born under favorable environmental conditions and in good physical condition do indeed seem capable of “having it all”: They experience higher rates of reproduction throughout life and longer lifespans than females born under adverse environmental conditions who are in poor physical condition.

Ecological theory presumes that organisms must divide what are usually limited resources between three major life processes: reproduction, growth, and survival, all of which contribute to an individual’s main goal: lifetime reproductive success. If an individual devotes some of those resources to reproduction, that implies there will be fewer available for growth and survival—in other words, there will be compromises in life. In terms of reproductive timing, greater early-life reproduction was therefore expected to reduce late-life reproduction and/or survival.

The Université Laval research team benefitted from 27 years of data observing mountain goats at Caw Ridge, Alberta, Canada, located in the foothills of the Rocky Mountains. In addition to the absence of evidence for early-late life compromises in the population, the researchers added to the growing body of research that points to the considerable influence of natal environmental conditions on reproduction and survival.

The researchers believe a better understanding of reproductive strategies in long-lived species such as mountain goats will help to provide insight into why wild populations might be increasing, decreasing, or stable in size, thereby contributing to the conservation and management of charismatic mammals such as the mountain goat. Read the Article