Cooperation

== Kin selection ==
One specific form of cooperation in animals is [[kin selection]], which can be defined as animals helping to rear a relative's offspring in order to enhance their own fitness.<ref name="Hamilton" /><ref name="Clutton" />

Different theories explaining kin selection have been proposed, including the "pay-to-stay" and "territory inheritance" hypotheses. The "pay-to-stay" theory suggests that individuals help others rear offspring in order to return the favor of the breeders allowing them to live on their land. The "territory inheritance" theory contends that individuals help in order to have improved access to breeding areas once the breeders depart. These two hypotheses both appear to be valid, at least in cichlid fish.<ref>Balshine-Earn, S., Neat, F.C., Reid, H., & Taborsky, M. (1998). "Paying to stay or paying to breed? Field evidence for direct benefits of helping behavior in a cooperatively breeding fish". ''Behavioral Ecology'', 9(5), 432–38.</ref>

Studies conducted on red wolves support previous researchers'<ref name="Clutton" /> contention that helpers obtain both immediate and long-term gains from [[cooperative breeding]]. Researchers evaluated the consequences of red wolves' decisions to stay with their packs for extended periods of time after birth. It was found that this "delayed dispersal," while it involved helping other wolves rear their offspring, extended male wolves' life spans. These findings suggest that kin selection may not only benefit an individual in the long-term in terms of increased fitness but in the short-term as well through enhanced chance of survival.<ref>Sparkman, A. M., Adams, J. R., Steury, T. D., Waits, L. P., & Murray, D. L. (2011). "Direct fitness benefits of delayed dispersal in the cooperatively breeding red wolf (''Canis rufus'')". ''Behavioral Ecology'', 22(1), 199–205. {{doi|10.1093/beheco/arq194}}</ref>

Some research even suggests that certain species provide more help to the individuals with which they are more closely related. This phenomenon is known as kin discrimination.<ref name="Griffin">Griffin, A. S., & West, S. A. (2003). "Kin Discrimination and the Benefit of Helping in Cooperatively Breeding Vertebrates". ''Science'', 302(5645), 634–36. {{doi|10.1126/science.1089402}}</ref> In their meta-analysis, researchers compiled data on kin selection as mediated by genetic relatedness in 18 species, including the Western bluebird, Pied kingfisher, Australian magpie, and Dwarf Mongoose. They found that different species exhibited varying degrees of kin discrimination, with the largest frequencies occurring among those who have the most to gain from cooperative interactions.<ref name="Griffin" />