Nobody likes bullies. Not even mongooses.
Say you’re watching an argument from the sidelines. No doubt you track the meanie in the bunch and make a mental note to avoid them later.
New research finds that mongooses do the same thing. They keep tabs on the aggressive behavior of other animals and then tuck that information away to act on it at another time.
Senior author Andy Radford, a professor of behavioral ecology at the University of Bristol in the United Kingdom, is the principal investigator of the Dwarf Mongoose Research Project, research that has been studying the wild animals since 2011. In the course of their studies, scientists spend many hours observing wild dwarf mongooses (Helogale parvula) every day.
“It is noticeable that there are often disagreements between group members, especially over juicy prey items,” Radford tells Treehugger. “Conflict is costly, so we wondered whether detecting aggressive interactions would have any effect on later behaviour, because there was no obvious change in the immediate aftermath.”
Because the animals were used to human presence, researchers were able to get up-close detailed field observations and they were able to perform experiments in natural conditions.
They published their findings in the journal eLife.
The Cost of Conflict
Conflict management is very important for all animal species. If conflict escalates, it can be harmful in various ways.
“For instance, contests take time and energy away from other important tasks (such as foraging and looking out for predators), there is the risk of injury or even death, and they can disrupt valuable relationships with others,” Radford says.
“As a consequence, conflict-management strategies have evolved in many social species. These take two main forms—those that prevent escalation in the first place and those that minimise the costs if escalated contests do occur.”
For their experiments, they simulated food contests between two group members by playing recordings in the afternoons of vocalizations made by aggressors and victims. The other mongooses in the group heard what sounded like repeated conflicts between those animals.
“One of the things that our new paper shows is that the mongooses use vocal cues of aggressive interactions to track their occurrence and who has been involved; they don’t need to observe the contest visually to gather that information,” Radford says
Mongooses typically groom each other regularly not just for hygiene reasons, but also to help ease anxiety. Grooming is a key part of social life, the researchers say.
But later in the evenings after they heard the recordings of the conflict, mongooses groomed one another even more than other evenings. Interestingly, perceived aggressors were groomed substantially less in the sleeping burrow by group members than they were at other times.
“Unlike in some other species, there was no evidence that there is an immediate change in behaviour after the aggressive interaction—for instance, there was no increased grooming between those not involved in the contest and the protagonists, which has been seen in lots of primates and other social species,” Radford says.
The mongooses tracked the aggressive behavior during the afternoon and acted on that information later in the day.
“We found that subordinate group members who had heard the simulated (by playback) aggressive interactions groomed one another more, but they reduced their grooming of the perceived aggressor—the dominant individual who the vocal cues suggested had been aggressive during the afternoon.”
Delayed Action
The behavior is particularly interesting because it is delayed. Earlier research analyzed grooming activity immediately after aggressive interactions. But this study examined behavior as long as an hour after the mongooses heard simulated conflicts and had already moved away from the area into their burrow.
“It is also noteworthy that the mongooses were able to obtain information about the occurrence of the aggressive encounters, and also about who seemed to be involved, just from vocal cues (evidenced because we used playbacks to simulate the occurrence of these contests),” Radford says.
He points out that it is also notable that it’s “bystanders”—individuals not involved in the aggressive interaction—who changed their behavior. It isn’t those who were a part of the conflict.
The findings are important, researchers say, because they broaden the concept of conflict-management behavior beyond what happens immediately after conflicts.
“We show that within-group aggressive interactions can have more lasting effects on behaviour between groupmates than previously demonstrated,” Radford says. “Conflict management is a key aspect of life for all social species, including ourselves, and so these findings have wide relevance.”
