The effects of food addition on life history of yellow-bellied marmots. Bliïanie dopolnitel’nogo pitaniïa na obraz jizni jeltobriukhikh sourkov. [Effets de l’addition de nourriture sur l’histoire de vie des marmottes à ventre jaune].

Résumé

We provided two social groups with supplemental food for several years (River Colony, June 1996-August 2000 and Marmot Meadow, June 1998-August 2000) to examine the effects of food addition on life history characteristics of female yellow-bellied marmots (Marmota flaviventris). We compared demographic and life history characteristics of supplemented females and reference females living within the same colony but adjacent home ranges. Supplemental food did not increase growth rates during gestation and lactation. Growth rates of supplemented mothers were higher only after weaning their young. There was no clear effect of food addition on survival rates, female recruitment, age of first reproduction, or reproductive effort, such as increased litter size or weaning masses of young. Social structure of yellow-bellied marmots is most likely the main factor influencing life-history characteristics and the role of food availability is minor.