Time and wariness in Yellow-bellied marmots

Abstract

The time budget of Marmota flaviventris was measured during the summer of 1990 to determine the pro-portion of time allocated to wariness, a set of behaviors in which a marmot scans the environment presumably to detect potential predators or conspecifics. Wariness occurred in three major forms: (1) sitting or lying on theground or on an elevated object; (2) alert, when an animal raised its head while walking or foraging; (3) vigilance, when an animal sat upright on its haunches with its forelegs held in front of its chest. Wariness occurred more fre-quently near the burrow area than far from the burrow area. Most time was allocated to inactivity such as sitting; only about 1.7% to 6.5% of above-ground time was spent feeding. Non-reproductive adult females that were socially subordinate to the reproductive female allocated more time to wariness and yearling females allocated more time to feeding than did the other animal groups. The reproductive female increased her wariness after her litter emerged. Various interactions among season, time of day, location, and animal group indicate adjustment of the time budget to prevailing conditions. The overall wariness strategy of marmots is to spend time near the burrow to assess potential risk before initiating foraging.