TRACK-A-MOLE: SNIFFER DOG AND eDNA HELP ‘REDISCOVER’ SOUTH AFRICAN GOLDEN MOLE

Scientists have uncovered gold in the dunes of South Africa’s northwest coast: the De Winton’s golden mole, a species not seen by scientists since 1936.

Like moles in general, De Winton’s golden mole (Cryptochloris wintoni) is blind and lives largely underground, navigating through the sand using sound and vibration. This lifestyle makes it particularly hard for humans to find.

However, researchers from the Endangered Wildlife Trust (EWT), a South African nonprofit, and the University of Pretoria used a sniffer dog and a technique called environmental DNA (eDNA) analysis to detect the presence of this small, elusive mammal.

The researchers trained a border collie named Jessie to identify the scent of common golden mole species. When the team arrived at the remote Port Nolloth survey site, heavy rains had revealed numerous fresh golden mole burrows and tracks. However, when unleashed to search the area, Jessie showed no signs that she recognized the scents of any moles there. Her lack of familiarity suggested to the researchers that De Winton’s species may have made these tracks.

The team collected more than 100 sand samples for environmental DNA (eDNA) analysis, which uses the DNA animals shed in the form of skin cells, hair and bodily excretions. By comparing the collected eDNA to known sequences from a mole closely related to De Winton’s, the team determined the samples contained a previously unknown species. However, more conclusive genetic evidence was needed to prove this was De Winton’s.

A breakthrough came when another research team published DNA analysis of a De Winton’s specimen held in the Port Nolloth museum, allowing EWT to match its original samples. When the team compared their eDNA sequences from the Port Nolloth beach to the new reference sequence, it matched De Winton’s golden mole.

“The amazing part for me is that it’s been there all this time, and nobody knew,” J.P. Le Roux, former EWT field officer, told Re:wild. “Now we finally know.”

EWT detected a likely thriving community of De Winton’s golden moles around Port Nolloth, as well as traces of other rare golden mole species in the soil samples, including Van Zyl’s golden mole (Cryptochloris zyli), not seen in 18 years.

The study area is currently unprotected and threatened by development and nearby diamond mining. EWT says it hopes to use the data obtained to advocate for protective status of De Winton’s habitat and to find additional populations using trained sniffer dogs.

“​​We need to identify areas to focus our conservation [efforts] and secure protected areas to make sure there’s still strongholds for these species,” Le Roux said. To help with this, EWT plans to train a new sniffer dog to find only De Winton’s golden moles.

De Winton’s moles are the 11th species from a list of 25 “most wanted” lost species that have been found again by science. Re:wild, working with partners across the globe, has confirmed species such as a stunning chameleon in Madagascar, the world’s largest bee in Indonesia,  a holly tree in Brazil, and an elephant shrew in Somalia.

“Now not only have we solved the riddle,” EWT senior manager Cobus Theron said, “but we have tapped into this eDNA frontier where there is a huge amount of opportunity, not only for moles, but for other lost or imperiled species.”