Dr. James F. Hare
My research program focuses on questions pertaining to the evolution and maintenance of sociality, and the roles that communication and cognitive abilities play in social species. My students and I employ both field research on ground-dwelling squirrels and controlled laboratory and field experiments on slave-making ants to address a variety of research questions.
Comparative Social Recognition in Ground Squirrels
By contrasting closely related species manifesting various levels of sociality, insight can be gained into the ecological correlates and evolution of sociality in that group. We have found that highly social Columbian ground squirrels become familiar with, and are highly amicable toward all members of their local group, independent of their degree of relatedness. In the less social Richardson’s ground squirrel, close relatives are treated most amicably, though neighboring group members are accorded more amicable treatment than non‑neighbors. Finally, in relatively asocial Franklin's ground squirrels, it seems that relatives only are afforded preferential treatment. Thus it appears that kin bias represents an ancestral pattern that ultimately gives way to the broader inclusion of group members in advanced vertebrate societies.
Alarm Communication in Richardson's Ground Squirrels
Communication among group members is essential to the integration of a society. Ground squirrels routinely employ alarm vocalizations to provide conspecifics with information about predators. Our research on Richardson's ground squirrel alarm communication has shown that callers communicate the extent of threat posed by a predator by varying the rate of syllable production within repeated calls. We have also shown that call recipients discriminate among individual callers, and use that ability to weight their response according to the past reliability of the calling individual. Further, caller discrimination appears to allow adult call recipients to adjust their response according to the number of calling individuals, revealing underlying numerical ability in these ground squirrels. Extensive variation in signal spectral structure may communicate even more exacting details regarding a predator encounter: recently we have shown that the incorporation of frequency-modulated "chucks" into audible calls allows receivers to pinpoint the location of the signaler, and that squirrels occasionally produce ultrasonic calls, thereby reducing their risk of being detected by predators, and limiting their audience to nearby relatives. Many opportunities exist for novel and exciting work on communication in ground squirrels.
Life-history of Franklin's ground squirrels
Little is known about the biology of Franklin's ground squirrels (Spermophilus franklinii), though this species is of considerable interest given its relatively asocial nature, and its low abundance through much of its historical range. My students and I have collected much-needed data on patterns of space use relative to kinship and on aspects of mating and reproductive success from two Franklin's populations since 1998, and thus are poised to address the functional basis of kin discrimination documented in my earlier research. Our field work on this species has also identified certain interesting and previously undescribed behaviors among these squirrels which represent promising prospects for future studies.
Social Recognition and the Biology of Slave-making Ants
Slave-making ants are socially parasitic species that raid the nests of their host species, "kidnapping" larvae and pupae that, as adults, augment the slave‑maker's work force. Enslaved workers thus propagate slave-maker genes at the expense of genes shared with relatives. My work on the Myrafant hosts of the slave-maker Protomognathus americanus has revealed that host-species workers prefer P. americanus larvae over conspecific larvae without any experiential modification of their brood acceptance behaviour. The chemical cues underlying that preference have yet to be elucidated, and further research is necessary. Further work is also warranted on what Prof. Tom Alloway and I described as "prudent social parasitism": the tendency of P, americanus to steward their host species populations, thereby ensuring an ongoing source of slave labour. Abundant opportunities exist for work on behavioural, chemical and evolutionary ecology with these slave-making ants and their hosts.
