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The next time you watch your dog visit the same places around your yard or notice that your cat seems to explore a new area every time it ventures outside, consider this: You might be witnessing an ancient evolutionary strategy in action.

A study in the Proceedings of the National Academy of Sciences reveals that wild canids have, on average, both a greater density of travel routeways and a greater probability of routeway usage than wild felids. Led by University of Maryland researchers, the collaborative study used GPS collar data detailing the movements of 1,239 individual carnivores representing 34 species across six continents over the past decade—the largest comparative study of carnivore movement ecology ever conducted.

"We found that carnivore species use space in fundamentally different ways," said the study's lead scientist, William Fagan, a Distinguished University Professor of Biology at UMD. "Members of the dog family appear much more structured in their uses of space. On average, they rely more heavily on favored travel routes compared to members of the cat family."

Fagan and his collaborators found that wild members of the dog family—wolves, foxes, coyotes, and others—consistently create and stick to specific travel routes within their territories. But their distant carnivore cousins in the cat family—from bobcats to lions and leopards—tend to roam more freely, relying less strongly on favored routes.

The findings challenge scientists' traditional understanding of the movement ecology of mammalian predators. Historically, researchers assumed that predators moved randomly throughout their territories, an assumption so widespread that it was baked into standard mathematical models. However, the new findings show that many carnivores create invisible "highway" systems that they use repeatedly to move through portions of their home ranges, perhaps thanks in part to the dogs' powerful sense of smell.

"We suspect that this split reflects deep evolutionary differences in how these species navigate and find their way around," Fagan explained. "Canids possess superior olfactory abilities compared to felids, potentially helping them establish and remember preferred travel routes. It looks like these different navigation strategies have developed over millions of years since dogs and cats last shared a common ancestor."

"Given the inherent heterogeneity in such a large, global dataset, the magnitude and consistency of these differences is striking," says senior author Justin M. Calabrese, head of the Earth System Science research group at CASUS in Germany and Adjunct Professor at UMD. "However, we were careful to check that the lineage-specific differences persisted even after controlling for many potentially confounding factors."

Intriguingly, the differences between canids and felids actually became stronger when the researchers restricted their analyses to nine shared landscapes where both canids and felids could be studied together, removing the influence of variation in vegetation type, human "footprints," and other factors across landscapes.

The researchers believe that their findings have many implications for improving wildlife conservation and management practices. Fagan noted that understanding and anticipating the regularity of animal movement patterns is crucial for predicting human–wildlife encounters and organizing conservation areas, particularly in protecting endangered species from threats such as poachers.

For example, Fagan and collaborators held a workshop at UMD's Brin Mathematics Research Center focusing on the links between movement, encounters, and the dynamics of disease transmission, mate-finding and predator–prey systems.

"This research was a massive undertaking, beginning as a multitude of email exchanges during the COVID pandemic and ultimately transforming into the world's biggest comparative carnivore movement dataset involving 177 collaborators around the world. The project demonstrated how modern GPS technology and sophisticated analysis methods developed by our research group can reveal fascinating hidden aspects of animal behavior that were impossible to study just a short time ago," Fagan said.