Animals with loose social bonds face greater extinction risk than highly social species

For decades, scientists believed that highly social animals like lions and capuchin monkeys were the most vulnerable to population decline. The logic seemed straightforward: species that depend heavily on group living should suffer the most when their numbers drop. However, groundbreaking new research reveals the opposite may be true.

A comprehensive study examining the relationship between social behavior and survival suggests that loosely social animals—such as agoutis and tapirs—actually face greater extinction risks when their populations decline. The research, which analyzed existing models, data, and case studies, uncovers a critical difference in how various species respond to population stress.

According to Michael Gil, co-author of the study from the University of Colorado Boulder, highly social animals maintain stable social interactions even as their numbers fall. When part of an African wild dog pack is killed, for example, survivors will desperately seek to join new groups because their immediate survival depends on it. These species essentially “figure out a way” to preserve their social structures.

Loosely social species respond very differently. As their populations shrink, their social interactions decline proportionally—and they don’t compensate for the loss. This creates what Gil describes as “a dangerous feedback loop.” Fewer squirrels means fewer eyes watching for predators. Smaller fish schools reduce collective hunting success. The resulting increase in mortality further reduces population size, creating an accelerating spiral toward extinction. This discovery could fundamentally change how conservationists prioritize protection efforts for at-risk species.