Cooperative Breeding in Meerkats
Biology 342 Fall 08
Daniel Bernstein and Justine Spencer
Why co-operate? What value does this have over evolutionary time?
Success in Numbers
Belonging to a group is necessary to survive the harsh environment in which Meerkats live. They huddle together for warmth, dig burrows together, and groom each other. They take turns on sentry duty, without which Meerkats could not feed safely. Group sizes are large to achieve the necessary strength to defend their territory. Meerkats must co-operate to achieve and sustain the success of the group, whereas individually this is not possible. Individual prospects for survival and reproduction rely on the survival and prosperity of the group as a whole.
Meerkats cannot produce offspring without the help of the group. An individual Meerkat simply cannot find enough food and protection to safely raise offspring. The group raises the young collectively, by feeding and protecting the young. As a result, pup survival increases with group size (Clutton-Brock et al, 2001).
However, there is a catch. Resources are too limited to care for the young of all females who become pregnant. The number of offspring must be controlled so that the young can be successfully reared into healthy adults. This means there is competition among females for who becomes pregnant. If the competition fails to reduce the number of offspring, infanticide is common (Young & Clutton-Brock, 2006).
Photo courtesy of nationalgeographic.com
Not Simple Altruism
Photo courtesy of nationalzoo.si.edu