Song dogs that were thought to be extinct reappear

The Papua New Guinea song dog species was believed to be extinct for 50 years.

However, a study published in the journal Proceedings of the National Academy of Sciences (PNAS) indicates that they still exist.

This species is known for its ability to make harmonic sounds that have been compared to that of a humpback whale.

Currently, only about 200 captive song dogs live in conservation centers or zoos.

However, none had been seen in their natural habitat.