We often ask, ‘why the hell dogs chase cats or rather, why the hell do dogs hate cats?’ To us, it looks like a very irrational behavior on part of dogs. However, prehistoric records say otherwise. In fact, this hatred has been embedded in dogs through evolutionary process over millions of years.
Fossil records from pre-historic turfs of our planet shows that dogs and cats had been through a very rough past where everything hinged on one thing – survive! Evidences show that cats and dogs had absolutely no contact with each other. Each species was even completely unaware of the presence of the other until cats crossed over from Asia and entered North America some 18.5 million years ago (mya).
Yes, that’s how aloof the two species of animals were. The canines (that include families like coyotes, wolves etc.) came to existence in area that we today call North America some 40 mya. For the next 18 million years, they thrived and increased in numbers and diversity until they reach their maximum diversity some 22 mya from today. By this time, 30 different species of canids were ruling the area.
All these findings come from a study that was conducted by an international team of scientists from universities of Lausanne, Switzerland; Sao Paulo, Brazil and Gothenburg, Sweden. The team took the pain of studying 2,000 different fossils and published their findings in Proceedings of the National Academy of Science – a journal.
According to the study, nearly half of these species went extinct on their own over the course of millions of years. The ancient canids, according to the scientists, were extremely large and some reached the weight of around 33 kilograms or 66 pounds. The extinct Epicyon and dire wolves were even larger and reached almost double the size mentioned above.
While the ancient dogs enjoyed their unrivalled rule, they were little aware of the fact that a formidable opponent was on its way to challenge them. Some 18.5 mya, ancient felines from Asia, managed to enter North America. They crossed what is known as Bering Land Bridge.
This bridge was just a natural formation – a mass of land that connected Asia and Alaska some 18.5 mya. Once in new turfs, these felids started settling down and inhabiting the area. As their numbers grew, they became a serious rival of the canids because both of them depended on the limited food source.
According to the researchers, it turned out that the felines who entered North America were better hunters than many of the already existing canines. Scientists are not very sure which specific canine species were affected by rising competition but they are pretty sure that one particular canine subfamily – the bone-crushing dogs – were the most affected ones.
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- 20 Interesting Cat Facts – Part IV
According to the scientists, as the ancient feline species started growing in North America, the bone-crushing dogs registered a sharp decline some 15 mya and eventually went extinct some 2 mya.
Researchers say that the sub-family of the bone-crushing dogs had about 60 species and all these species were the ones that were worst-hit by the competition from the felines and eventually embraced extinction. This happened because the bone-crushing dogs and the ancient felids both depended on the same food source and with felids. With limited food sources and ancient felids being more efficient killing machines, these dogs – all 60 species of the subfamily – were drove to extinction.
The same type of competition is prevalent even today, specifically in Africa where canines like hyenas and wild dogs compete with felines like big cats.
So, the ancient canids, over millions of years were threatened by the felids and developed a natural instinct to drive the felines away. This instinct passed down from generations to generations and continue to exist to this day in all the 9 species of canines known to us now. Yes, from 30 different species and a wide range of subspecies, the canines have now been reduced to only 9 species which includes our domestic dogs and through all these years, they nurtured their instinct of chasing cats away.