An ancient dog known for its uniquely haunting howl was, until recently, feared vanished from the wild. But a team of intrepid researchers confirmed the rediscovery of the rare dog, a finding that has big implications not only for the conservation of its kind but also the broader story of canids in Oceania.
Last month in the Proceedings of the National Academy of Sciences, researchers announced that enigmatic pooches from the Central Cordillera of New Guinea are likely the ancestral stock from which today’s New Guinea singing dogs – up until now, thought to survive only in captivity – derived.
The largest terrestrial predator in New Guinea, the singing dog is so-named for its high, keening call, one which the authors of the study note has been “described as a ‘wolf howl with overtones of whale song.’” Much resembling a smallish dingo, it was first formally described in 1897; in the 1950s, collectors obtained a pair of dogs that ultimately ended up at Sydney’s Taronga Zoo. That “original” duo is among the mere eight individuals from which today’s genetically vulnerable, inbred population of perhaps 200 to 300 captive singing dogs derives. An absence of sightings of free-ranging individuals in lowland New Guinea and the proliferation of domestic dogs on the island suggested wild singing dogs had dwindled away – or, in the opinion of some scientists, had never been a distinct wild race in the first place, but rather were simply feral domestic dogs or perhaps a hybrid of domestic dogs and dingos.
But how, or whether, these singing dogs related to elusive canids periodically sighted in the Central Cordillera was a matter of speculation. Those “highland wild dogs,” as they’re called, had been captured on film only twice before a 2016 field expedition into the Sudirman Range of Indonesia’s Papua Province identified 15 wild dogs in the vicinity of the Grasberg Mine, a giant open-pit gold and copper mine in the shadow of New Guinea’s highest peak, Puncak Jaya. That fieldwork – headed up by James McIntyre, president of the New Guinea Highland Wild Dog Foundation – gathered photographs of the canids as well as faecal material (wild dog doo-doo).
The DNA analysis published in PNAS results from a followup expedition to the same area conducted in 2018, during which researchers (including McIntyre) were able to gather blood samples from three highland wild dogs: two that were live-trapped and GPS-collared, a third that had been apparently killed by a vehicle.
If you have half an hour, here's a documentary chronicling the 2018 trip:
Comparing the genetic makeup of those highland wild dogs with the captive New Guinea singing dogs, Australian dingos, and many domestic dog breeds, the researchers found a strong affiliation – roughly 72 percent – between the highland and singing dogs, which in turn are closely related to dingos. The team concluded that highland wild dogs likely represent the original population from which today’s genetically deteriorated captive stock of singing dogs sprang.
In other words, highland wild dog and New Guinea singing dog seem to be one and the same, and thus the former, the PNAS study’s authors propose, “should be resourced for conservation efforts to rebuild this unique canid population.”
The study found highland dogs claim a more diverse genome than their captive cousins, which isn’t unexpected given the latter’s heritage of inbreeding. The greater genetic variation of highlands dogs may represent a better-preserved picture of the singing dog’s original genome as well as, perhaps, the contribution of at least some interbreeding with domestic dogs.
The re-discovery of a wild population of singing dogs, and their blood ties to dingoes – plus, to a lesser extent, certain domestic breeds such as the akita and the shiba inu – also offer clues to the evolutionary history and patterns of domestication in the dogs of Asia and Oceania. “They provide this missing piece that we really didn’t have before,” Elaine A. Ostander of the U.S. National Institutes of Health, a co-author of the new study, told the New York Times.
Speaking to CNN, another co-author and a colleague of Ostrander’s at the National Institutes of Health, Heidi Parker, said the DNA work showed that highland wild dogs “are in a branch of a tree together with dingos, which suggests that singing dogs and dingos and highland wild dogs split off really early. They’re much older in terms of dog development.”
As a 2007 review in Australian Mammalogy noted, local people in New Guinea clearly distinguish between village dogs and highland wild dogs. Historically, the latter were taken from the wild as puppies by some native cultures to rear as hunting companions – a tradition of “taming” singing dogs, the paper emphasises, but not of domesticating them, a process that involves humans breeding animals for particular traits.
“Singing dogs were highly valued by highland hunters because they helped to increase the products of the hunt several times over,” the Australian Mammalogy paper stated. “Those hunting dogs that excelled in their services to their human partner were treated as an honorary human in their final burial rites, and their bones were placed in branches of a forest tree, while the jaws of their kills decorated the human hunter’s house.”
The close kinship between the New Guinea singing dog and the Australian dingo, meanwhile, has long been suspected given the strong morphological similarities. Indeed, the singing dog has sometimes been pegged as the dingo’s probable immediate ancestor. The dogs may have journeyed to Oceania some 6,000 to 8,000 years ago when a land bridge connected New Guinea and Australia, but dingo ancestors could also have reached the island-continent with seafaring people. How and when these dogs spread through Oceania remain fertile veins of research. The Australian Mammalogy review noted that canid remains in New Guinea have been dated to 5,500 years ago. Recent genetic work suggests at least two lineages of dingo in Australia, perhaps the outgrowth of two separate colonisation episodes. A study published earlier this year in Nature Communications analysed dingo and singing-dog DNA and, besides confirming their close genetic relationship, suggested they arose some 8,300 years ago from a Southeast Asian line of ancestral dogs.
The authors of the PNAS paper stress that its exciting revelation is also a call for further investigations: The current size and range of the highland wild dog population in New Guinea is still unknown, and they call for genetic sampling and field research on dogs “from more remote regions along the central range such as Puncak Mandala, Puncak Trikora, and equally remote areas on the Papua New Guinea side” of the island.
Besides clarifying the status of free-roaming highland wild dogs, such work could address the limited genetic diversity of the captive population. “Conservation efforts will benefit most from inclusion of the greatest number of specimens that best represent the original dogs, with the least amount of influence from outside sources,” the authors write, “making it imperative that these studies be continued.”
Header image: Anang Dianto/New Guinea Highland Wild Dog Foundation
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