C Cooperative Grooming

Grooming functionally serves different hygienic purposes such as removing dead skin and parasites. Therefore, it is an important part of hygienic routine in most animals and is strongly associated with survival. In many species, individuals do not only groom themselves but are also frequently observed grooming conspecifics (reviewed in Spruijt et al. 1992) or even individuals from other species (cleaning symbiosis; Poulin and Grutter 1996). Within species, besides increasing hygiene, allogrooming relaxes the receiving individual, serves as appeasement gesture to reduce aggression between partners, can be part of courtship behavior, and facilitates social bonds such as between mother and offspring or between individuals of a social group. However, allogrooming imposes important costs to the donor, such as decreasing their predator vigilance or time spent foraging. Symbiosis, kin selection, direct reciprocity, and being part of complex social functions are the main mechanisms proposed through which donor individuals may gain benefits and increase their fitness via grooming a conspecific.