DOGS ON THE TRAIL OF SOUTH AFRICA’S ENDANGERED TORTOISES

With her snout pressed to the ground, a Border Collie named Delta weaved eagerly through the shrubs of a private nature reserve near Cape Town, intently sniffing for critically endangered tortoises.

Suddenly, Delta stopped in front of a small bush and lay down—her signal that she had found something. Her handler quickly moved in to investigate the area.

Hidden in the tall grass was a tiny reptile, its shell adorned with yellow star-like patterns—a distinctive feature of the geometric tortoise, a species native only to the southern tip of Africa.

“It’s an adult female; you can tell by its flat belly,” said Esther Matthew, Delta’s handler and a conservation officer with South Africa’s Endangered Wildlife Trust.

Matthew explained that the organization trains dogs to detect the tortoises by “building a positive association with their scent,” rewarding Delta with a foam frisbee each time she locates one.

“Dogs are five times more effective than humans at these searches,” Matthew added, “and they help us find smaller tortoises that are often missed—like hatchlings and juveniles.”

“We’ve seen a dramatic increase in the number of finds thanks to the dogs.”

Their assistance has become vital in studying and protecting the geometric tortoise, a species found only in South Africa’s Western Cape province and now on the brink of extinction.

Biologist Andrew Turner, who works with the conservation authority Cape Nature, explained that the species’ population was already as low as 1,500 individuals in the wild by the early 1990s. Today, it’s estimated to number only a few hundred, with declines occurring across almost its entire remaining range.

During a survey on the nature reserve, Delta and Matthew—joined by colleagues searching the bushes with sticks—located a dozen of these resilient reptiles.

“We record all the tortoises we find, collecting data, measurements, and weight,” said Matthew.

With the geometric tortoise’s natural habitat shrinking due to agriculture and urban development, such surveys have become increasingly critical, Turner noted.

“There are very few places left in the Western Cape that still support these tortoises. Mostly just a handful of nature reserves and some patches of suitable habitat on private land,” he said.

“These remaining vegetation patches are largely isolated from one another, separated by farmland, roads, towns, and industries, limiting the tortoises’ ability to disperse and bolster other populations.”

This habitat fragmentation leaves the tortoises even more vulnerable to threats like drought, predation, and fires—events scientists believe are growing more frequent and severe due to climate change.

Poaching, both of the tortoises and the plants they depend on, also poses a serious risk, Turner added.

“They’re at such low numbers that they need as much help as possible,” he said.

To protect the species, the Endangered Wildlife Trust has been working to build partnerships with landowners and local communities living in the tortoise’s habitat.

“The biggest priority is creating corridors that allow species to move through the landscape,” said Zanne Brink, who leads the trust’s dry lands conservation program.

“Our greatest challenge is gathering enough information to prevent critical biodiversity areas from being lost to unsustainable land use.”