Prehistoric and Extinction: Do Dogs Recall Prey Competition?

Dogs may have an age-old reason to fear and dislike cats, it turns out.

That is, after felids (wild cats) moved to North America from Asia in prehistoric times, they pretty much took over. In fact, as many as 40 canid (wild dog) species became extinct as a result, say scientists from the Universities of Gothenburg (Sweden), São Paulo (Brazil), and Lausanne (Switzerland). The cat impact on dog diversity at that time was more deadly than climate change, the researchers recently reported in the journal PNAS.

In the study, the researchers analyzed more than 2000 fossils.
"We usually expect climate changes to play an overwhelming role in the evolution of biodiversity. Instead, competition among different carnivore species proved to be even more important for canids," said lead author Daniele Silvestro at the Department of Biological and Environmental Sciences, University of Gothenburg, in a statement.

Dog family history in North America began about 40 million years ago and reached a diversity height around 22 million years ago--with more than 30 dog species. Now, only 9 species of canid live on this continent, the statement said.

Dogs in the early days also steadily increased in size and became large predators. Some weighed more than 66 pounds and held ground among the largest predators in North America. But researchers found no evidence that dogs, as large predators, faced extinction risk based partly on size-despite the fact that today, some large carnivores face a high extinction risk, according to the release.

There was probably always a great deal of competition for food. For instance, today, African wild dogs, hyenas, lions, and other felids compete for prey. The research of early North America shows that the felids were not negatively impacted by the dogs, which suggests that the wild cats must have been more efficient predators than most of the now-extinct dog species, the release said.

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