Outside conflict makes some animals more cooperative with each other
According to a new study from the University of Bristol, dwarf mongooses become more cooperative and work closely together when faced with potential violence from rival groups.
While conflict among rivals is common throughout the animal world, the consequences of this behavior are relatively unknown. The current study provides evidence to suggest that the threat of clashes with outsiders causes changes in a range of group behaviors.
“Much is known about the behavior that occurs when groups of the same species actually interact with one another,” said study lead author and PhD student Amy Morris-Drake. “However, we have shown that the threat of between-group battles can lead to increases in within-group cooperation, including greater grooming of group mates and contributions to sentinel duty (acting as a raised guard).”
“Experimental tests of the consequences of out-group conflict are extremely rare, especially on wild animals,” added study co-author Professor Andy Radford. “By working with groups of dwarf mongooses habituated to our close presence, we could collect detailed observations and conduct experimental manipulations in natural conditions.”
Some experts believe that high levels of cooperation in human societies stem from the need to unite in times of war. Through this study, the researchers found a similar link among animals.
“We tested our theories by simulating territorial intrusions of rival groups,” explained Morris-Drake. “To do so, we used call playbacks and faecal presentations, creating the impression that trouble-makers had crossed the border into a group’s own land.”
“We then carefully observed the behavior of the resident group after they had interacted with the cues of rivals, and found differences compared to control conditions,” said Professor Radford. “Individuals groomed one another more and foraged closer together, potentially due to higher anxiety levels; their increase in sentinel behaviour was likely an attempt to gather more information about the threat.”
The findings suggest that the effects of warfare can be identified in the threats as well as in the actual fights, and that the indirect impacts on societies must be considered as much as the outcomes on the battlefield.
The study is published in the journal Behavioral Ecology.
Image Credit: Shannon Wild