Paper 7 - R. Kiat

Paper 7: McNab, 1963 – by Rebecca Kiat

McNab, B. K. (1963). Bioenergetics and the determination of home range size. The American Naturalist, 97(894), 133-140.

Commentary by James H. Brown and John L. Gittleman

Brian K. McNab

·      Emeritus Professor at the University of Florida

·      Ph.D. University of Wisconsin

·      Research interests: “Ecological and physiological influences on the comparative energetics of endotherms, with special emphasis on tropical mammals and birds and on the evolution of endothermy.”

James H. Brown 

·      Professor of Biology at the University of New Mexico

·      Ph.D. from the University of Michigan

·      Research interests: “Community ecology and biogeography, with special projects on granivory in desert ecosystems; biogeography of insular habitats; and structure of dynamics of geographic-scale assemblages of many species.”

John L. Gittleman

·      Dean and UGA Foundation Professor in Ecology at the University of Georgia

·      Ph.D. from the University of Sussex

·      Research interests: Evolutionary biology, Biodiversity and conservation, Phylogenetics

The body weight of an organism will influence its rate of energy expenditure and subsequently how much food it needs to consume – how then does body size-in terms of energetics-relate to home range? In this paper, McNab continues the discussion on body weight and the home range of mammals, but extends the conversation to include an allometric and metabolic perspective (note also: Fenchel, 1974 – Paper 13).

            The size of the home range in mammals is determined by the rate of metabolism. However, there are other factors that should also be considered that is likely to play a role in the home range of a species, such as the type of food the species consumes (active hunters vs. croppers – see Figure 1), as wells as the habitat type and the type of climate the species is found in – there may also be seasonal trends due to e.g. breeding season, food availability.

Questions:

Note: The basal rate is technically the minimal rate of energy expenditure/unit time of an animal at rest.

Can we apply basal rate of metabolism for all mammal species e.g. across different sizes, different climates and in the ‘field’?

McNab highlights the usage of the basal rate of metabolism as a representation for the rate of energy exchange for mammals and recommends caution in doing so. Thoughts on basal rate of metabolism vs. total daily expenditure? (Also, the basal rate is technically the minimal rate of energy expenditure/unit time of an animal)