It’s hard to believe that in 2021 it could still be possible for humans to discover a brand-new mammal. Yet that’s precisely what has happened. Scientists recently released a description of the new species, along with a video of its unique-sounding call.
The adorable little creature—dubbed Dendrohyrax interfluvialis—is a species of tree hyrax, in other words, a small herbivorous mammal. The nocturnal animal was first noticed by a team of researchers back in 2009, who heard its distinct bark-like call during a night expedition in Nigeria. The calls of tree hyraxes living between the Niger and Volta rivers do sound more like barks when compared with those living in other regions of the African forest zone, which use shrieking vocalizations.
In the video below, you can hear the call of the previously known species of tree hyrax followed by the call of the newly discovered hyrax:
“Sometimes a keen ear is as important as a sharp eye,” said Eric Sargis, curator of mammalogy and vertebrate paleontology at the Yale Peabody Museum of Natural History. “My co-authors Joh Oates and Simon Bearder were in Nigeria in 2009 researching galagos, a group of primates, when they noticed that the hyrax calls were different on one side of the Niger from the other. All the evidence we subsequently studied, including the distinctive vocalizations, points to a unique species in the forests between the Niger and the Volta.”
Scientists also found that there were notable anatomical and genetic differences between the two species. These variations included different skull shapes and sizes, fur colors, and that the interfluvial populations were genetically distinct from others.
“There is increasing evidence that the Niger and Volta Rivers are significant biogeographic barriers to a range of mammals,” said Oates. “Hyraxes, for instance, don’t cross water easily, so it makes sense that, through millions of years of changing climate, as African forests have expanded and contracted, new species would have differentiated in isolated forest fragments known as refugia, and then have been limited in their subsequent dispersal by large rivers.”
So, this new species of tree hyraxes is likely just one of many unique animal species in that distinct between-the-rivers region, which is exciting! However, researchers warn that the region is unfortunately under severe threat due to the ever-growing human population, commercial logging, agriculture, and hunting.