A mouse-sized elephant shrew that had been lost to science for 50 years has been discovered alive and well in the Horn of Africa.
The Somali sengi mates for life, can race around at 30km/h and sucks up ants with its trunk-like nose. But it had not been documented by researchers since 1968.
In 2019 scientists set out to search for the animal following tips from the region, but not in Somalia, from where the only past reports had come, but in neighbouring Djibouti. Locals were able to identify the creature from old photographs with Houssein Rayaleh, of Association Djibouti Nature, saying he had seen the animal before.
The team tapped into local knowledge, and the fact that the sengis need shelter from birds of prey, to set traps in likely locations, baiting them with a concoction of peanut butter, oatmeal and yeast. They caught a Somali sengi in the very first trap set in the dry, rocky, landscape, identifying it by the tuft of fur on its tail that distinguishes it from other sengi species.
“It was amazing,” said Steven Heritage, a research scientist at Duke University in the US. “When we opened the first trap and saw the little tuft of hair on the tip of its tail, we just looked at one another and couldn’t believe it. A number of small mammal surveys since the 1970s did not find the Somali sengi in Djibouti – it was serendipitous that it happened so quickly for us.”
The team was happy not to witness any looming threats to the sengi’s habitat, which is largely unsuitable for human activities such as development or agriculture, suggesting a secure future for the creature. “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, of the Global Wildlife Conservation (GWC) group.
The team set more than 1,000 traps at multiple locations and saw 12 sengis in total, obtaining the first photos and video of live Somali sengis for scientific documentation. DNA analysis showed that the Somali sengis are most closely related to other sengis that live as far away as Morocco and South Africa.
This meant they have now been placed in a new genus, Galegeeska. It also meant that that an animal with a territory smaller than an average-sized backyard has somehow dispersed across great distances over time, leaving biologists with a new sengi evolutionary mystery to solve. Sengis are most closely related to aardvarks, elephants and manatees.
Andrew Taylor, the chair of the International Union for the Conservation of Nature’s specialist group covering sengis, said: “In a single expedition to a part of Africa that is challenging to work in, the team have achieved remarkable success. Not only have they formally documented the continued existence of the Somali sengi for the first time in 50 years, they have also corrected our understanding of the species’ genus.”
“For us living in Djibouti, we never considered the sengis to be ‘lost’, but this new research does bring the Somali sengi back into the scientific community, which we value,” Rayaleh said. “For Djibouti this highlights the great biodiversity of the country and shows that there are opportunities for new science and research here.”
The GWC’s Search for Lost Species project includes a 25 “most wanted” list, with the Somali sengi previously the fifth creature waiting to be rediscovered. The others include Jackson’s climbing salamander, in Guatemala, and Wallace’s giant bee, in Indonesia. “This wonderful sengi rediscovery fills us with renewed hope for the remaining small mammal species on our most wanted list, such as the De Winton’s golden mole and the Ilin Island cloudrunner,” said Moore.