“THIS is an ideal place for manatees,” says Lucy Keith-Diagne, squinting at a gradual, muddy sweep of the Niandan river. It appears unbelievable: why would these lumbering aquatic mammals, additionally known as sea cows, be dwelling some 4000 kilometres up the Niger river in Guinea, nearly as near the Sahara desert as to the Atlantic Ocean? However because the world professional on African manatees, Keith-Diagne would know.

These chubby creatures are identified to reside decrease down the Niger river, which stretches like a large boomerang via a lot of West Africa, and anecdotal proof over time has hinted at one other inhabitants excessive up in tributaries close to its supply. What’s extra, Keith-Diagne believes this group has been separated from different manatees for therefore lengthy that its members might be evolving right into a separate subspecies. “They went up the Niger. They discovered great things. They stored going. They by no means got here again and so they turned totally different,” she says. However, for now, that is only a guess.

To search out out extra, we have now pushed a whole lot of kilometres from Guinea’s swampy coast, over the highlands and down into the forested savannah in quest of these elusive creatures. In a two-week expedition, Keith-Diagne and her group will interview locals, chase up any leads on latest sightings and search for telltale indicators of feeding alongside riverbanks. Crucially, they may also accumulate samples of…