Seasonal variation in the foraging activity of desert argali (Ovis ammon) in Mongolia

Canadian Journal of Zoology,Volume 97, Issue 10, Page 931-939, October 2019. Debate remains whether energy maximization or time minimization strategies best explain foraging in ungulates. It has also been hypothesized that the capacity of an animal to dissipate body heat regulates animal activity. We investigated these hypotheses while measuring the daily activity of desert argali (Ovis ammon (Linnaeus,1758)) for 12 months and relating the activity pattern to environmental seasonality. We found significant seasonal cycles in argali activity, with the greatest proportion of daytime in winter spent foraging and the greatest proportion of daytime in summer spent bedding. Consistent with an energy maximization strategy, argali reduced all behaviors during the winter in favor of foraging, compensating for the increased energy demands of winter at a time of low forage quality. Consistent with a time minimization strategy, argali in summer significantly reduced foraging and spent more time bedding in shaded areas to avoid hyperthermia due to high ambient temperatures. Both optimal foraging and heat dissipation can be used to explain the observed foraging pattern. Foraging behavior in argali is best described by the extent to which the animals schedule their activities to meet their physiological demands, the way these demands are affected by environmental variables, and the time that is available to accomplish them.
Source: Canadian Journal of Zoology - Category: Zoology Authors: Source Type: research