WATERMAN, J.M.; University of Central Florida: Why African ground squirrels hang out with mongooses: are there benefits to interspecific associations?

Predator detection and deterrence are major benefits of sociality for many small mammals, and these benefits may extend to interspecific groups. In southern Africa, Cape ground squirrels (Xerus inauris) often share burrow systems with two species of mongoose, suricates (Suricata suricatta) and yellow mongooses (Cynictis penicillata). Each of these three species lives in highly social groups of conspecifics; for squirrels, this grouping reduces the amount of time spent vigilant and increases feeding. These species are usually very tolerant of one another, and Cape ground squirrels may benefit from the vigilance of suricates and the anti-snake behavior of mongooses; however, this hypothesis has never been tested. I observed Cape ground squirrels near their burrows in the presence and absence of suricates and yellow mongooses to determine if squirrels benefitted from these interspecific relationships. Squirrels spent significantly less time vigilant and more time resting in the presence of suricates, but time spent feeding was not affected. Vigilance was reduced much further by the presence of other squirrels than the presence of suricates. When snakes were present, Cape ground squirrels were actually more active in mobbing the predator than were yellow mongooses or suricates. Thus, there does seem to be some benefit from associating with these other species, but the survival benefits of associating with conspecifics are much stronger.