The influence of reproductive status on foraging by hoary marmots (Marmota caligata)

Summary Predictions were made and tested, comparing the foraging behavior of reproductive (rf) and nonreproductive (nrf) female hoary marmots, with the following findings: In June, no differences occur between rf's and nrf's, regarding daytime foraging. However, rf's forage more in the evening and during inclement weather, suggesting that greater nutritional needs and higher reproductive value select for the assumption of more risk while foraging. These differences disappear by August, when nutritional needs and reproductive values of rf's and nrf's are comparable. Finally, rf's reduce their near-burrow foraging relative to nrf's, which minimizes competition with their own young.