(CNN)This dog can sing ... or at least it can yodel.
The New Guinea singing dog, an extremely rare breed, is best known for its unique barks and howls -- it's able to make harmonic sounds that have been compared to the calls of a humpback whale.
Only around 200 captive singing dogs live in conservation centers or zoos, the descendants of a few wild dogs captured in the 1970s. The animals are severely inbred due to a lack of new genes.
None had been seen in their natural habitat for half a century until 2016, when an expedition located and studied 15 wild dogs in the remote highlands of the western side of New Guinea, known as Papua, in Indonesia. A new expedition returned to the study site in 2018 to collect detailed biological samples to confirm whether these highland wild dogs truly are the predecessors of the singing dogs.
A comparison of DNA extracted from blood collected from three of the dogs suggested they have very similar genome sequences and are much more closely linked to each other than any other canine, according to research published on Monday in the journal PNAS.