Time budgets for 17 behaviors were analyzed for cohort, day-period, season-period and interactions among the main effects for three colonies of yellowbellied marmots in the Upper East River Valley in western Colorado. These effects explained up to 79% of the variation in the behaviors. Marmots allocated more time (40-60%, 110-265 min daily) above-ground to sitting/lying than to any other activi...

Yellow-bellied marmots (Rodentia: Sciuridae) typically hibernate for eight months. This study explored energetic costs of hibernation in young and adults at 10 and 6 degrees C. Age significantly affected the percent time torpid, total and mass-specific VO(2), use of energy during torpor, and daily mass loss at 6 degrees C. Thus young had a higher mass-specific VO(2) during a torpor bout, which ...

Ecological factors explain variation in sociality both within and between species of marmots-large alpine ground squirrels. Fifty years of study, by me and my colleagues, of the yellow-bellied marmots (Marmota flaviventris) at the Rocky Mountain Biological Laboratory, near Crested Butte, CO, USA, has created opportunities to see how sociality changes with population and group size. Over the pas...