Predator Threat Boosts Friendships Among Guppies, Study Finds

A new study finds that danger from predators causes animals to form stronger friendships. The researchers Scientists from the University of York, University of Exeter and University of the West Indies, St Augustine, conducted a study on the reaction of Trinidadian guppies with regards to danger and predators and found the fish developed stronger and more stable social bonds when they thought predators were in the area.

The researchers report that their findings coincide with social groups being smaller which invariably suggest a likely conflict between the ability of the guppies to form strong social relationships and the ability to live in larger social groups. Their finding is the first experimental evidence which reveals that proximity to predators can lead to the intensity of animal social bonds.

"This research is important in our efforts to understand why social bonds and friendships form," study's first author, Dr Robert Heathcote from Exeter's Centre for Research in Animal Behavior. He added that the influence of dangerous environments on social relationships are also present in humans, just like between soldiers who form strong and long-lasting bonds during active duty in war zones, according to Eurekalert.

Previous studies on the topic have revealed that guppies recognize other individual guppies and then develop long-lasting and stable social relationships with each other. While conducting the experiment during the study, the researchers kept some of the fishes in pools, some were exposed to model predators, and others were not.

Since guppies often quit and join new shoals, the researchers decided to measure their social ties by seeing how often the same fish swam together. They found that although, all guppies developed stronger social bonds when faced with predators, the effect was strongest among larger and bolder individuals who are at higher risk.

Many animals are known to form large social groups in order to gain protection from predators, but the researchers discovered that guppies formed smaller groups as they strengthened their social ties. They believe that this could be reflective of the conflict between the benefits of forming larger groups and those of forming stronger bonds, according to Science Daily.

A co-author on the study, Dr Safi Darden stated that maintaining a good social relationship usually requires individual recognition, which can be difficult when it involves large number of individuals. The researchers published their findings in the journal Scientific Reports. The study was supported by Danish Council for Independent Research and the Natural Environmental Research Council, Leverhulme Trust.