Kin Selection for Alarm Calls in Belding Ground Squirrels

 Ground Squirrels (Spermophilus beldingi) live in colonies of related individuals. Like other mammals, some members of the colony emit alarm calls at the approach of predators. The data show that pre-reproductive juveniles males and females emit calls at about equal rates, whereas reproductive adult females with offspring and relatives in the colony emit calls at a substantially higher rate than males, even though the behavior increases the danger to themselves. The behavior appears to be partially learned: pre-reproductive yearling females also emits calls at a higher rates than males, even though they do not yet have offspring of their own.