The Dhole (Cuon alpinus) is recognized as a canid endemic to Asia. But it has an evolutionary history that is far more complex and interesting. Contemporary Dhole populations are divided into two subspecies – the Northern (Tien Shan) and Southern (Ussuri) Dholes. Once upon a time, there were many more races, spread over a far greater range, and even in continents that are now devoid of wild Dholes. The earliest member of the genus Cuon was the species Cuon majori of Early Pleistocene China (living between 2.5 to 1.8 million years ago). It resembled the Canis species much more than its modern day descendants. The two genera might have diverged between 3.6 to 2.6 million years ago (in the Late Pliocene).
By the Middle Pleistocene (between 781,000 to 126,000 years ago), Cuon species had grown large (almost to the size of a Gray Wolf) and dispersed from Central Asia to Central and Western Europe. Some paleontologists have classified the large European specimens as Cuon stehlini. Others call them Cuon priscus. They would be replaced by Cuon alpinus arriving from Asia in the later half of the Middle Pleistocene. Cuon alpinus also crossed the Bering Land Bridge into North America by the Late Pleistocene (between 126,000 to 5,000 years ago). The world of the Late Pleistocene was a snow world, created by the Wurm (the Alps), Weichselian (Northern Europe), Zyryanka (Siberia), Fraser (the Pacific Cordillera) and Wisconsin (central North America) Glaciations.
Dholes ranged across the entire Northern Hemisphere. The formation of gigantic glaciers and ice fields all over the globe led to a drop in sea levels, opening up land bridges to islands that had been cut off from mainland Asia. That is how the species spread to Sri Lanka, Borneo, Palawan and Japan. In North America, Dholes could be found as far south as Mexico. One particular subspecies, the European Dhole (Cuon alpinus europaeus) was even larger than the Ussuri Dhole, rivaling Gray Wolves (Canis lupus). Dhole populations might have survived in Europe and North America as recently as 12,000 years ago. Habitat loss (caused by changes in climate), decline in the numbers of large ungulate prey (a major challenge for a hypercarnivorous species) and competition with other canids (more suited to the rapidly changing conditions) might have pushed it to extinction.
Image Attribution: The image above, sourced from Wikimedia Commons, shows a pack of Northern Dholes pursuing an Argali. It is taken from the book ‘Mammals of the Soviet Union’ (1988), edited by V G Heptner and N P Naumov.
- San Diego Zoo
- The IUCN Red List of Threatened Species
- Walker’s Carnivores of the World by Ronald M. Nowak
- Research Gate
- The Guardian