Posts Tagged ‘Canis lupus familiaris’

The American Dingo

February 11, 2013

The famous dingo of Australia is an ancient breed of dog that has gone feral.  Aborigines colonized Australia ~40,000 years ago–probably before man domesticated dogs–and there is no evidence they brought dogs with them.  Instead, some humans from the subcontinent of India apparently brought dogs with them to Australia about 5,000 years ago.  The Indians assimilated with the aborigines, and many of the dogs they brought reverted to a wild state and became a top predator on the island continent.  Asians also brought this ancient breed of dog with them when they colonized America.  Scientists don’t know exactly when the ancestors of modern dogs were first domesticated, but it was probably about 12,000 years ago.  (Some genetic studies suggest dogs began to evolve from wolves as long as 100,000 years ago, but many of those early lineages died out.)   In America, just as in Australia, this ancient breed of dog goes feral.  The circumstances likely varied.  If a tribe died out naturally or was destroyed by another tribe, dingos were capable of reverting to a wild state and surviving without their human masters.  On occasion some may even have purposefully escaped captivity.  In any case American dingos weren’t recognized as a distinct wild canid until the 1970’s.  Dr. Lehr Brisbin jr., a research ecologist for the University of Georgia at the Savannah River Ecology Lab, first noticed them running wild at the Savannah River Site in South Carolina.  This area itself  reverted to wilderness when the federal government purchased the land surrounding a nuclear reactor.  Dingos have since been discovered on the Fort Gordon army base in Georgia and other lightly populated areas across the south.  Dr. Brisbin has given tame American dingos the common name of Carolina dog.

An American dingo.  Adults weigh between 40-60 pounds.  They’re an ancient breed of dog capable of surviving without humans.  Tame dingos are known as Carolina dogs.  A Korean dog, the chindo-ka, is probably the same ancient breed.

I’m not sure what scientific name to give the American dingo.  When adopted, wild puppies make good pets, though they require 24 hour companionship and attention.  And they breed with other dogs.  In human households and backyards, they can be given the scientific name Canis familiaris–the domestic dog.  Australian dingos are given the scientific name Canis lupus dingo–and are considered a subspecies of wolf.  Wolves and dogs can interbeed and produce fertile offspring as well, and some scientist give dogs a wolf subspecies status with the name Canis lupus familiaris.  But others consider dogs a separate species based on differences in behavior patterns and some slight physical differences.  The classification of species is an invention of man and in this case murky.

Wild dingos reproduce faster than domesticated dogs.  It’s thought that they breed rapidly to overcome natural mortality from parasites, such as heartworm.  They are much better hunters than domesticated dogs.  They instinctively know how to pounce on mice and shrews with their forepaws.  They are snake-killing specialists.  Dingos bite the snake and whip their neck around, cracking the snake’s vertebrae.  Domesticated dogs don’t know how to do this.  Dingos form packs and also hunt raccoon, rabbit, and probably deer.   Nursing dingos bury their feces and dig numerous small pits around their dens. The dens are burrows they dig themselves or take from other animals.  These behaviors also differentiate them from domesticated dogs.

Young pups from a wild dingo are easily domesticated and reportedly make good pets, but they require constant care.  Dingos follow their human masters everywhere and, if escape from an enclosure is possible, they will figure out how immediately.  They are an intelligent breed.

Dingos are probably the oldest breed of domesticated dog still extant and are more closely related to wolves than other breeds.  This would explain their ability to survive in the wild without people.  When native Americans were forced to leave southeastern North America, they must have left many of their dogs behind.  An increased wild dingo population must have already been established by the 1830s because Indian tribes had been decimated by European diseases.  In the mid-19th century there were still hundreds of square miles of wilderness in the south where humans and domesticated dogs were scarce, and dingos could thrive.  Then, following the Civil War, vast acreages of agricultural land were abandoned.  American dingos served as top predators in these “waste” places after cougars and wolves were exterminated by settlers.  Many settlers adopted dingos, and this is the breed of dog celebrated in the famous children’s novel, Old Yeller, by Fred Gipson.  It’s kind of surprising they weren’t recognized as a wild canid until recently, but most people that saw them probably thought they were just somebody’s dogs that got loose.

Today, the American dingo is in danger of becoming extinct in the wild.  Increasing conversion of abandoned farmland to suburbs is bringing them into contact with domesticated dogs, causing them to become genetically swamped when they interbreed.  And coyotes may be outcompeting them.  Both coyotes and dingos occupy the same niche–marginal wilderness habitats where larger predators are rare or have been eliminated by man.

The University of Florida Museum of Natural History database lists 9 specimens of Canis familiaris from the late Pleistocene fossil record found in Florida.  This is evidence the Paleo-indians brought dogs with them somewhat earlier than scientists think dogs were domesticated.  The breed they brought with them was most likely the dingo.  For a few millennia wild dingos likely shared the landscape with Pleistocene megafauna.

References:

Brisbin jr., I.L.; and T.S. Risch

“Primitive Dogs, their Ecology and Behavior: Unique Opportunities to study the Early Development of the Human-Canine Bond”

Journal of American Veterinary Medical Association 210 April 1997

Pigoch, Iris; et. al.

“Genome-wide Dates Substantiate Holocene Gene Flow from India to Australia”

PNAS 110 (5) Jan 2013