A little-known mammal related to an elephant but as small as a mouse has been rediscovered in Africa after 50 years of obscurity.
The last scientific record of the “lost species” of elephant shrew was in the 1970s, despite local sightings.
The creature was found alive and well in Djibouti, a country in the Horn of Africa, during a scientific expedition.
Elephant shrews, or sengis, are neither elephants nor shrews, but related to aardvarks, elephants and manatees.
They have distinctive trunk-like noses, which they use to feast on insects.
There are 20 species of sengis in the world, and the Somali sengi (Elephantulus revoilii) is one of the most mysterious, known to science only from 39 individuals collected decades ago and stored in museums. The species was previously known only from Somalia, hence its name.
Steven Heritage, a research scientist at the Duke University Lemur Center in Durham, US, and a member of the expedition to the Horn of Africa in 2019, said he was thrilled to put the species “back on the radar”.
He told the BBC: “We were really excited and elated when we opened the first trap that had an elephant shrew in it, a Somali sengi.
“We did not know which species occurred in Djibouti and when we saw the diagnostic feature of a little tufted tail, we looked at each other and we knew that it was something special.”
The scientists had heard reports of sightings in Djibouti, and Houssein Rayaleh, a Djiboutian research ecologist and conservationist who joined the trip, believed he had seen the animal before.
He said while people living in Djibouti never considered the sengis to be “lost”, the new research brings the Somali sengi back into the scientific community, which is valued.
“For Djibouti this is an important story that highlights the great biodiversity of the country and the region and shows that there are opportunities for new science and research here,” he said.
Peanut butter bait
The team set more than 1,000 traps at 12 locations, baiting the traps with a concoction of peanut butter, oatmeal and yeast. They caught one of the creatures in the first trap they set in the dry, rocky landscape of Djibouti.
In total, they saw 12 sengis during their expedition and obtained the first-ever photos and video of live Somali elephant shrews for scientific documentation.
They did not observe any immediate threats to the species’ habitat, which is inaccessible and far from farming and human developments.
The abundance of the species seems similar to other elephant shrews and its range may extend beyond Somalia into Djibouti and possibly Ethiopia.
The Somali sengi is one of the 25 “most wanted lost species” of the charity, Global Wildlife Conservation.
“Usually when we rediscover lost species, we find just one or two individuals and have to act quickly to try to prevent their imminent extinction,” said Robin Moore.
“This is a welcome and wonderful rediscovery during a time of turmoil for our planet, and one that fills us with renewed hope for the remaining small mammal species on our most wanted list, such as the DeWinton’s golden mole, a relative of the sengi, and the Ilin Island cloudrunner.”
DNA analysis shows that the Somali sengi is most closely related to other species from as far away as Morocco and South Africa, placing it in a new genus.
The mammal has somehow dispersed across great distances over time, leaving biologists with a new puzzle.
The scientists plan to launch another expedition in 2022 to GPS radio-tag individual sengis to study their behaviour and ecology.
Kelsey Neam of Global Wildlife Conservation added: “Finding that the Somali sengi exists in the wild is the first step in conservation. Now that we know it survives, scientists and conservationists will be able to ensure it never disappears again.”
The research is published in the journal Peer J.
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