Population time budget for yellow-bellied marmots at high elevation site [Budget-temps d'une population de marmottes à ventre jaune d'un site à haute altitude].

Résumé

Time budgets for six behaviors were analyzed for a population of yellow-bellied marmots (Marmota flaviventris) at 3400 m elevation in the Upper East River Valley in western Colorado. Behaviors were divided into six categories: vigilant, foraging, antagonistic behaviors, sitting/lying, grooming, and locomotion. We compared our results to a previous study on time budgets of marmots at lower elevation sites. We hypothesized that the shorter growing season of higher elevation sites would influence time budgets of marmot populations. Marmot allocated the majority of their time to sitting/lying followed by foraging. High elevation populations spent 61% (278 min daily) or their time sitting, 19% (85 min daily) of their time foraging, and 7% or less of their time was spent on the remaining categories. Yearlings spent more time foraging (29%) compared to adult marmots (15%). Yearling females spent 41% of their time foraging compared to males who spent only 16% of their time foraging. However, high elevation yearling males had higher growth rates than female yearlings. Marmots must adjust their behaviors to maximize energy intake in preparation for hibernation. Although length of active season can decrease with elevation, marmots at higher elevation do not appear to be constrained by available foraging time. The variation in foraging time among marmots of different sex, age class, or elevation remains unclear.