South Africa

Saturday, July 19, 2025

In the vastness of a private South African reserve near Cape Town, a border collie advances rapidly between grasses and shrubs. His nose scans the vegetation for geometric tortoises, a critically endangered species endemic to the region.

“Its population is so low that the slightest problem can quickly cause it to become extinct in the wild,” explains Andrew Turner, ecological restoration specialist for Cape Nature, the biodiversity conservation authority for the Western Cape region.

The three-year-old bitch is closely monitored by her owner, Esther Matthew of the NGO Endangered Wildlife Trust (EWT), who checks that the entire area has been surveyed. In front of a bush, Delta stops, scans and lies down. Esther Matthew waves to her colleagues. “She’s found one! It’s an adult female, you can tell by her flat belly. Males have a curved belly.”

You then have to get up close and stare at the fynbos, a vegetation unique to the region, to make out the carapace, which is perfectly camouflaged in the flora.

The geometric turtle is bumpy, with each bump streaked with yellow, like the branches of a star. Females are the largest, up to 16.5 cm long, and weigh up to 850 grams.

The conservation specialist pulls out a foam Frisbee to reward Delta. “If she finds a turtle, we give her a toy which encourages her to find more. But she doesn’t stop for just any turtle; we train her to stop only for the geometric turtle.”

It’s hard to put a number on them, as they’re so hard to find. In the 1990s, we estimated that there were 1,500 individuals,” says Andrew Turner, “which isn’t very many. Later estimates put the number at between 600 and 800. Today, the population is not thriving anywhere. It would be safe to say there are still a few hundred.”

According to Esther Matthew, dogs are five times more effective than humans in this type of research. “They use their sense of smell, not their eyesight. In particular, they help us find the smallest turtles, newborns and juveniles, which we often miss.”

– Database –

After Delta, it’s time for Dash, a younger border collie, to continue the search. They are assisted by colleagues on foot who search the shrubbery with sticks. That day, a dozen or so geometric tortoises were located on the reserve.

Then the information gathering begins: “We mark the shell of each new turtle found, measure it, weigh it and record everything in our database”.

This census is essential, at a time when the destruction of their habitat is threatening them with extinction.

These turtles have a very specific habitat,” stresses Andrew Turner. They can only be found in the Renosterveld and the Fynbos, where they feed.”

These unique vegetations of the Cape region are themselves threatened with imminent extinction.

– Fragmented plots –

“The diversity of plants in these areas is incredible,” he continues. But because the soils there are so rich, they have been taken over by agriculture and these plants have largely disappeared.”

“The remaining patches of vegetation are increasingly fragmented amid farms, roads, towns and industrial sites,” confirms the ecologist. “So turtle populations are no longer connected and can no longer sustain themselves.”

The smaller and more fragmented the geometric tortoise’s habitat, the smaller the population and the less able it is to cope with climatic hazards such as droughts, increasingly frequent and intense fires, and attacks from predators such as Pied Crows.

Nor is poaching, of which geometric tortoises, like the plants they eat, are victims. “They need all the help we can give them,” pleads Andrew Turner.

“Our role is to gather as much data as possible on these species,” posits Zanné Brink, head of the drylands conservation program at EWT. “Then we set up partnerships with landowners, for example, to help them protect the flora and fauna on their land.”

“There is an awareness of the richness of our biodiversity in the Western Cape and the threats to it,” confirms Turner.

“Our biggest challenge,” concludes Zanné Brink, “is to gather enough information to prevent the disappearance of essential areas of biodiversity due to damaging land use.”

Humaniterre with AFP