Many species, including humans, can discriminate among individuals according to genetic relatedness. Yet how this kin recognition is accomplished remains largely unexplored. Belding's ground squirrels, Spermophilus beldingi, are group-living squirrels that exhibit many forms of nepotism (preferential treatment of relatives), including cooperative territory defense and predator avoidance, which require the ability to identify relatives. The PI's previous NSF-supported research showed that S. beldingi produce at least six individually distinct odors which can be used for social recognition, as well as several odors that vary with relatedness. The proposed research seeks to demonstrate for the first time a direct, causal association between odors, recognition mechanisms and preferential treatment of relatives. These studies will determine how this species uses odors for recognition, examine the limits of kin discrimination, and describe how kin-recognition abilities facilitate inbreeding avoidance. The ability of animals to use different recognition mechanisms in different contexts would be favored in unpredictable social environments; thus this research will test the hypothesis that if S. beldingi lose all memories of kin during hibernation they must later rely on their own odors to help them recognize their kin in the spring. Theory also predicts that animals will avoid mating with close kin; these studies will therefore determine whether kin-recognition abilities also function in mate choice, using observational and genetic techniques. They will test whether the recognition abilities used to treat particular kin classes favorably are the same as those used to avoid close inbreeding. This research program is among the first to examine if particular odors have numerous, overlapping functions and whether there are commonalities between the mechanisms of recognition in multiple contexts. Given the importance of social relationships for understanding speciation, population dynamics, mating systems and reproductive success, the proposed research offers a unique opportunity to integrate both mechanistic and functional levels of analysis for an understanding of kin recognition in both mating and nepotistic contexts. Recognition abilities can either promote or limit adaptive responses to kin, and the combined field and laboratory components of this research will facilitate exploration of these outcomes. The results of the proposed research can be applied to studies of social recognition in a variety of taxonomic groups, and can also be applied to captive breeding and re-introduction programs, particularly if social recognition influences the formation and stability of social groups or their mating success. This project will support the interdisciplinary training of a postdoctoral scholar and, indirectly, 2-3 graduate students from several programs on the University of Chicago campus. Students will be trained in theory and concepts as well as field and experimental techniques, integrating proximate and ultimate approaches to behavior, ecology and evolution. Each year of the award will also support participation of 4-5 undergraduate field assistants, giving them an opportunity to experience field biology regardless of income or prior experience. Historically, assistantships have been offered to females and ethnic minorities, as both groups tend to be discouraged from fieldwork. The award will also be used to promote further development of a multi-user molecular genetics facility, as well as to produce lectures and lay articles for the local communities near the field site.
