Rescuing the rare Geometric Tortoise
Earlier this year a destructive fire in the Elandsberg Nature Reserve threatened the survival of the iconic geometric tortoise. Fortunately, CapeNature didn’t waste a minute in coming to the rescue of these rare reptiles and a rehabilitation project has since been established.
The Elandsberg Nature Reserve near Wellington previously supported 80% of the total population of geometric tortoises. Unfortunately, a January veld fire destroyed the majority of their habitat, raising serious concern about the survival of this species.
Along with help from the University of the Western Cape (UWC) and Elandsberg Nature Reserve, scientists from CapeNature launched a search-and-rescue operation. Their goal was to remove as many live geometric and common padloper tortoises from the damaged veld as possible.
“This [the fire] is a devastating blow to tortoise conservation in the reserve and geometric tortoises in general, and illustrates how vulnerable land tortoises are to wildfires in these relatively small and isolated land parcels,” says Dr Ernst Baard, head of CapeNature’s Scientific Services. “Although all South African tortoise species are protected by law, this does not automatically protect them from the threat of their habitat disappearing.”
Whereas earlier research estimated the geometric tortoise population at around 2 000 animals, post-fire calculations show a significant decline in the population. Until the winter rains revive their burnt habitat, 60 or so rescued geometric tortoises are being kept in veld elsewhere. Throughout this period, the tortoises are observed and weighed regularly to keep track of their health.
“By studying their reproduction, we will learn a lot about how these animals respond to such extreme events, and this will help us in planning our strategy on how to maximise their survival,” says Professor Margaretha Hofmeyr of UWC’s Biodiversity and Conservation Biology department. Hence the drive for more research into the habitat, preferred vegetation, diet and reproduction of the females that survived the fire, as well as the creation of an ‘orphanage’ for geometric tortoise hatchlings.
The root of the problem
The main threat to the geometric tortoise is habitat loss. This species is restricted to fertile lowlands and valleys, but the vast majority of its tiny natural range has been taken over by farms and housing developments.
Geometric tortoises occur on just over 20 properties, from the Swartland and the west of the Cape Fold Mountains to the Ceres valley and the Upper Breede River valley, where they survive in lowland renosterveld vegetation. A number of private landowners in the Boland area have small geometric tortoise populations on their properties and hold the future of this species in their hands.
According to Baard, the geometric tortoise is the only one of South Africa’s 12 land tortoises facing extinction. The geometric tortoise is fully protected by national and provincial conservation laws, and it is therefore illegal to collect, transport, have in captivity, export or trade in this species.
The Western Cape government has also set aside a few specially-conserved areas that cater to this unique tortoise’s habitat requirements and specific diet of local plant species.
Anybody who is aware of geometric tortoises on their property and needs more information is welcome to contact Dr Ernst Baard at CapeNature on 021-866-8001 or at firstname.lastname@example.org.