Cooperation
Naked mole-rats display several behaviors that do not benefit their own reproductive success. This is made possible because by how related naked mole-rats are, which makes kin selecting behaviors more beneficial to the individual performing the “altruistic” act than in most other species. In most species siblings are related by a factor of 0.5 in naked mole-rats, siblings are related by a factor of 0.81, and even aunts or uncles are related by 0.72. This has occurred because naked mole-rats breed with individuals outside of there colony extremely infrequently, which has caused naked mole-rats to become the most inbred species of mammals recorded (Hudson et al., 1990).
Care for young, gathering
food, limited breading possibilities, and sacrificing
oneself to protect the colony are
all examples of naked mole-rat cooperative behavior, doing what is best for
the colony (but also what will pass as much
of their genetic material on to the next generation as possible). Non-breeding
colony members will expend energy both to care for young (that are not their
own) and to gather food, both of which will not help them to bear pups of
their own (Jarvis, 1981). As a result of the mating system in naked
mole-rats, most
individuals will never mate (Reeve and Sherman, 1991). Naked mole-rats also
commit the ultimate sacrifice as a result of kin selection: sacrificing themselves
to help protect the colony. If a snake attacks a colony, entering the via
a molehill, a naked mole-rat will block the hole with dirt from the
outside, in doing
so this individual will be eaten by the snake, but will protect the rest
of the colony from any further predation for the time being (Brett,
1991a).
This web site was completed in partial fulfillment of the requiremtns for Biology 323, Animal Behavior at Davidson College in the Spring Semester of 2003.