A breed of wild dog known for its lyrical sounds may not be as extinct as we thought, according to a new paper out Monday. The study details genetic evidence suggesting that the New Guinea singing dog — thought to have only existed in captivity for the past 50 years — is still alive in the wilds of Indonesia. The authors say their findings confirm that the New Guinea singing dog is in fact the same as the Highland wild dog, a dog that’s been spotted in the area in recent years.
New Guinea singing dogs produce distinctive, high-pitched noises, and, unlike domesticated dogs, they don’t bark or yip. They’re native to the remote mountainous Highlands of the island of Papua New Guinea, and they’re closely related to the dingos found in nearby Australia. Spanish navigators described the dogs in written records during the early 17th century, and archaeological evidence suggests the dogs have existed there for thousands of years.
These singing dogs were a rare sight to begin with, given their geographical isolation from humans and general shyness, though people living in the area would occasionally adopt them. But by the 1970s, they were assumed by scientists to have dwindled to nothing. Since then, various zoos and conservation centres have raised captive populations of New Guinea singing dogs, bred from a handful that were collected from the island, and their numbers are thought to be no more than 300 in total.
In recent years, however, there have been several alleged sightings of wild dogs in New Guinea that look very similar to the New Guinea singing dogs; these dogs were named Highland wild dogs. Some conservationists were quick to suspect these Highland wild dogs were a surviving population of singing dogs, but the evidence wasn’t definitive. Other experts have argued that the first singing dogs bred in captivity over 50 years ago weren’t fully wild dogs at all, but dogs that had long intermingled with domestic breeds raised by local villagers.
In 2016, researchers in the U.S. and Indonesia were finally able to find and photograph 15 Highland wild dogs in their natural environment. Two years later, they collected blood samples from some of these dogs and studied their behaviour more closely. Along the way, the group began a collaboration with scientists from the National Human Genome Research Institute (NHGRI), part of the U.S. National Institutes of Health. And the later expedition allowed the genetic researchers to fully sequence the dogs’ DNA and compare it to the DNA of captive singing dogs and other dogs.
Their new findings, published today in the journal PNAS, appear to confirm that Highland wild dogs are very genetically close to the captive singing dog population, more than most any two breeds of domestic dogs are from one another. That’s not to say there aren’t differences between them. The captive dogs are much less genetically diverse, thanks to the inbreeding needed to sustain the very small population of founding dogs. The Highland wild dogs, on the other hand, seem to possess genes that were lost in the captive dogs over time, having around 30 per cent more genetic diversity.
But the dogs are so closely related to one another, the authors say, that they belonged to the same original population of wild dogs not too long ago, and the Highland wild dogs are effectively New Guinea singing dogs that managed to survive mostly hidden away from humans all these years. Not only that, the hope is that we’ll be able to bring back genetic diversity into captive populations by breeding them with their wild counterparts.
“Assuming these Highland wild dogs are the original New Guinea singing dogs, so to speak, that really gives us a fantastic opportunity for conservation biology,” senior author Elaine Ostrander, head of the research group at NGHRI studying these dogs, said by phone. “It’ll give us a chance to to reintroduce the original genetics of these dogs into this conservation population.”
Singing dogs, dingos, and domestic dogs are all considered the same species, though dingos and singing dogs are thought by many scientists to be a subspecies distinct from domestic dogs (modern wolves are another family tree branch of canines, wholly separate from dogs). Both singing dog and Highland dog populations seem to have genes that were once found in the common ancestor of all dogs living today but which have since disappeared in fully domesticated dogs. So these reclusive wild dogs also represent some piece of the legacy of ancient dogs that would have otherwise faded away completely.
According to co-author Heidi Parker, singing dogs, Highland dogs and dingos may very well be the last truly wild dogs around, distinct from domestic dogs and those that went feral later on. Understanding what makes them different could also very well provide insight into how most dogs became our best friend.
“These three populations of dogs are very similar to each other, and very distantly related to most dogs today, the modern dog breeds. And it appears that this separation took place long before all of the breeds formed or even before the dogs split into a different continent. So this is a very old breed,” Parker, a researcher at the NHGRI, said. “So this gives us a very different way to look at dogs and how they evolved.”
The researchers plan to continue surveying the island’s populations of Highland wild dogs, including in higher elevations where they might be even more genetically distinct from other dogs. By studying the intricacies of their melodies, we might also better understand how the capacity for singing evolved in animals more closely related to humans than to birds.
It’s their singing ability, Ostrander said, that makes conservation efforts to save them all the more meaningful.
“It’s not just that they’re wild and that they represent this last wild population, but they do make this beautiful vocal, harmonic sound, which distinguishes them from all the other populations of dogs anywhere,” she said. “They’re really something quite unique and quite special. And as a species, we don’t want to lose them from the face of the earth.”