AUBURN – Research by an Auburn University doctoral student is drawing connections in science magazines to Kevin Bacon, the Hollywood actor whose name has become synonymous in the popular culture with social networks among celebrities.
However, Theo Manno, a doctoral candidate in biological sciences, has found three degrees of separation, on average, not six, among his subjects, none of which are the famous actor, and none of which are American or even human. Yet Manno’s research on free-ranging, wild Columbian ground squirrels in Alberta, Canada, found some parallels with human social activity.
The research findings, recently published in the journal “Animal Behavior” and featured in the magazines “Discovery News” and “New Scientist,” also could have implications for social policy affecting management of natural resources.
Expanding upon studies by Stephen Dobson, a professor in the College of Sciences and Mathematics at AU, Manno and two assistants – including AU education Master’s student Lili DeBarbieri – observed the interaction of a colony of 65 ground squirrels in a nature park in the western Canada province from April-July 2006 and ran the results through a computer model. The model ran on software known as UCINET, which has been used by scientists in a variety of disciplines to identify networks on the Internet and among airline hubs as well as social connections among animals and even among humans.
The computer analysis identified two communities that were further divided into two and four subgroups, respectively.
Using a wilderness research site Dobson has used for more than a decade, Manno confirmed that ground squirrels are social animals and found that their social groups have some of the same characteristics as those of humans. For instance, the colony’s extroverts are so friendly with members of their groups that the larger, most structured social networks form around them. He also noted that groups accepted outsiders in their midst if the outsiders were friendly with a member of the group but were rejected them if that connection did not exist.
As expected, the social groups are at their strongest during the mating period, and Manno also confirmed that dynamics of the groups change over time, with females having less social contact even with other females after giving birth. Yet, the groups maintain their cohesion as long as the most socially active individuals remain in their midst.
Although mating behavior figured prominently in relationships between males and females, individuals were amicable with members of the same gender when mating was not the primary factor of group dynamics, Manno observed.
He defined amicable, “friendly” interactions as instances in which ground squirrels “kissed,” sniffed, played together or groomed one another.
While the socially active animals grouped themselves into networks with each other, Manno found that squirrels that were less socially active formed their own, smaller networks. “It is a lot like high school,” Manno said, noting the first networks that most Americans encounter outside the family.
To tell the individuals apart, the researchers trapped, marked and released each squirrel at the start of the project. To avoid further contact with the animals, the researchers would climb aboard a platform five feet above the forest floor each morning before the ground squirrels left their burrows and would climb down each day after the squirrels retreated to their nests for the night.
Manno, who earned his bachelor’s degree from Rider University in New Jersey, is on course to receive a doctorate from AU in August. After he earns his doctorate, he will head to the Southwest, where, before coming to Auburn, he worked as an assistant to University of Maryland researcher John Hoogland in studies of the social behavior of prairie dogs. Some of the techniques learned in that work carried over to his studies at Auburn, Manno said.
The AU researcher said similarities can be found between the animal networks and networks of all types, not just humans. Since many animals form social groups, the research could have implications for public policy regarding wildlife. For instance, in computer simulations he removed certain individuals of the colony. When those individuals were selected at random, their removal had little impact on the cohesiveness of the networks until the removal exceeded 10 percent. Yet when the group leaders were removed, he found that the networks deteriorated.
Wildlife management authorities could use the results to prevent the spread of disease in an animal population, Manno said, by identifying and removing the central figures in a colony. As the group breaks apart, the remaining individuals would have less contact with one another, thus reducing their risk of infection.
The findings, which are consistent with studies of other socially cohesive animal populations, also raise questions about hunting policy that encourages the killing of “trophy” animals. These are the largest, most prominent members of a group and are often male. In such cases, the group will usually disperse, and the females may not join another group or find another mate until the following year, reducing the colony’s population more than the hunt totals indicate. In such cases, random hunts would be better than trophy hunts for maintaining a stable population, he said.
Dobson, himself an internationally prominent authority on behavioral ecology, said Manno’s research is a significant advance in the biological sciences. “I consider Theo’s work as critical to understanding the general principles that govern social life in simpler rodent societies and have extensions to our own social evolution,” Dobson said.
“My collaboration with Theo is one of the highlights of my career,” added Dobson, whose own international reputation in the sciences earned him induction in 2002 into the Order of the Academic Palmes, France’s highest academic honor.