By modeling wolves in Yellowstone National Park, researchers have discovered that how a population is organized into social groups affects the spread of infectious diseases within the population. The findings may be applicable to any social species and could be useful in the protection of endangered species that suffer from disease invasion. Like other social carnivores, wolves tend to form territorial social groups that are often aggressive toward each other and may lead to fatalities. During these encounters, infectious diseases like mange and canine distemper can spread between groups, which can further reduce the number of individuals in a group. Previous social group-disease models have assumed that groups do not change throughout the course of an infection, when in reality, this is unlikely to be true. Individuals within groups may die, become infected and recover at different rates, and the group may split into multiple groups or multiple groups could combine into one.

The researchers used demographic data from two decades of Yellowstone wolf research to create models for examining the effects of sarcoptic mange and canine distemper virus on wolves that accounts for both within-group and between-group processes. The models assume that disease processes, such as transmission rates, vary among groups and within groups. This finding emphasizes the need for representative sampling in socially structured populations as pathogen outbreaks in unsampled groups can be missedWildlife researchers and managers should sample from many groups in a population in order to accurately depict disease prevalence.