The New Guinea Highland dog is native to the island of New Guinea. They are unique among their Canidae biological family because of their status as a rare representative of wild dogs, isolated habitat, and vocalization. These mysterious and ancient dog species once resounded throughout the island’s valleys and mountains but they have been thought to have gone extinct in the wild 50 years ago.
The discovery of the New Guinea singing dogs (NGSD)
A new study suggests, though, that the wild dogs living near a gold mine in New Highlands are the same as the singing ancestral dog population. This means that they still thrive and are stealthily wandering on the island, a finding that could open a new door for protecting such a remarkable creature and could teach us about human vocal learning.
Authors Suriani Surbakti from the Department of Biology in the Universitas Cenderawasih and the team said that the NGSD is identifiable because of their namesake vocalizations. Their presumption that their population only exist in captivity was probably because there was a lack of sightings in the lowlands of the island and the expansion of Asian- and European-derived dogs.
Dogs that can make harmonic sounds
It was in 1897 when the NGSD was first studied and their species became known for their vocalization as they can make harmonic and pleasing sounds with tonal quality. Only about 200 to 300 captive NGSD species exist in conservation centers and none was observed in the wild ever since the 1970s.
Senior author Elaine Ostrander, Ph.D., who is also the Distinguished Investigator in the National Human Genome Research Institute, told Phys.org that the captive NGSD that we know of today is a breed that was created by people. Eight of them were brought to the US from the Highlands of New Guinea and they were bred with each other to create the group.
A large amount of inbreeding, however, altered their genomic makeup by reducing the variation in the NGSD group’s DNA and it threatens their survival. It may also be because of this that the captive NGSD today has lost a large number of their genomic variants that existed only in their wild counterparts. Before the discovery of the NGSD in the wild, their origins remained a mystery to scientists.
Surbakti and the team hypothesized that the Highland wild dog may be the predecessor to the captive NGSD but it is difficult to test such theory due to lack of genomic information and the reclusive nature of the Highland wild dog.
In 2016, the Highland Wild Dog Foundation even collaborated with the University of Papua researchers to lead an expedition to Puncak Jaya, a mountain in Papua, Indonesia. The team reported sightings of 15 Highland wild dogs near the largest gold mine in the world called Grasberg Mine.
Collecting blood samples from the Highland wild dogs
Then, in 2018, the researchers conducted another field study in the area to collect blood samples from three Highland wild dogs while they are in their natural environment as well as their behavioral data, physiological data, and their demographic.
National Human Genome Research Institute staff scientist Heidi Parker, Ph.D. led the genomic analyses of the said blood samples and they compared the DNA of the Highland wild dogs and the NGSD. That was when they found that they indeed have a “very similar” genome sequences. It was even much closer to each other compared to any other canine they know. Dr. Parker added that if they would look at it in the tree of life, this makes the Highland wild dogs much more related to the captive NGSD than other modern breeds, like the bassett hound and the German shepherd.
Comparing the genome sequences of NGSD and Highland wild dogs
The researchers explained that the NGSD and the Highland wild dogs do not have the identical genome sequence because they have been physically separated for several decades and also because of the inbreeding that occurred among the captive NGSDs and not because they are of different breeds.
The authors even believe that the Highland wild dogs are the original and wild New Guinea singing dog population. Therefore, despite their different names as of now, they are still the same breed, in essence. Their study also provided that the NGSD is not extinct in the wild.
Significance in the study of human vocal disorders
Surbakti and colleagues believe that the NGSD can be used as a unique and valuable animal model to study how human vocal disorders arise as well as the possibility of searching for treatment opportunities.
For most of us humans, our voices play an important part in what we do, how we communicate, and in who we are. Like our fingerprints, each person’s voice is also unique. Yet, many things can injure our vocal cords and can lead to problems, such as polyps, nodules, and sores on the vocal cords. According to the American Speech-Language-Hearing Association, voice disorders have been estimated to be present in between 3 to 9% of the US population.
The occupational groups that appear to be most at risk for developing a voice/vocal disorder include teachers, factory or manufacturing workers, salespersons, and singers. In a recent study that appeared in peer-reviewed open access journal MDPI, authors Yaping Tao from Yancheng Teachers University and colleagues also highlight the relevant work factors associated with voice disorders in early childhood teachers. Through cluster sampling, 414 teachers from five public kindergartens in Yancheng, China, and 203 teachers from four public elementary schools in the same school district participated in the study. Voice problems among kindergarten teachers were higher than elementary school teachers.
The top voice symptoms were hoarseness (72.4% among kindergarten teachers and 59.2% among elementary school teachers), dryness (70%, 50.2%), tired voice (67%, 48.3%), ache (51.2%, 44.1%), and scratchiness (45.8%,37%).
Recurrence of vocal fatigue in different voice types
In another study about vocal fatigue in professional opera singers, they also showed the percentage of vocal fatigue reoccurrence among different voice types. They found that sopranos (40.00%) and tenors (25.45%) were most frequently affected by the reoccurrence of VF.
The discovery of the ancestral dog population can help researchers gain a more accurate insight into how vocal deficits happen and not rely heavily on birdsong data.