Territorial behavior may help animals flatten disease curve

Territorial animals may be buffering themselves against disease transmission through behavior similar to social distancing in humans.

While illness may still spread between individual animals through scent cues or other avenues of infection, this social distancing probably helps flatten the curve for transmission.

“It flattens the curve but helps the pathogen persist for longer,” said Lauren White, a researcher at the National Socio-Environmental Synthesis Center in Maryland and the lead author of a study published recently in PLOS ONE Computation Biology that uses mathematical models to link animal movement with the spread of disease.

Previous disease transmission models didn’t really take behavior like territoriality into account, White said, and they assumed that individual animals encounter each other at the same rate.

But this doesn’t necessarily reflect the reality of some animals’ behavior.

White and her co-authors simulated scenarios involving a high density of animals that recovered slowly from a given disease, a low density that recovered quickly and other variations. When comparing territorial versus non-territorial behavior, they found that simulated, territorial populations had higher disease peaks.

Their model showed that when animals were more territorial, disease infected fewer individuals at any given time, but the overall epidemic stuck around for longer in the population.

The simulation also showed that pathogens spread more in areas where some species’ leave their scents. Pumas (Puma concolor), for example, mark the edges of their territories with their scent. While male pumas usually stay out of each other’s areas, there are some overlaps at the edges of their turf where there may be interaction, particularly around these scent marks or in the surrounding area. Male territories also can overlap with the territories of several females.

Pathogens may be able to pass from one host to another through these scent marks, and White said that the study suggests that some pathogens may have even evolved to spread through indirect contact.

She and her colleagues plan to expand their models in the future to include other factors where animals may interact such as kill sites or the way that different habitat types may affect disease spread.

Header Image: Populations of territorial animals like pumas may be affected differently than more social animal populations. Credit: National Park Service