Africa, Animals
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A Creep of Tortoises

A Blog for Jabulani. Read the post here >

“Oh, a very useful philosophical animal, your average tortoise. Outrunning metaphorical arrows, beating hares in races… very handy.” – Terry Pratchett

Strategy, that’s what’s needed. In order to be there at the end of the race, you need a strategy. To be a participant in the race of life requires a well-conceived plan. And so the tortoise grew a shell.

Of course, in that amazing, fun, random and seemingly experimental way that nature has, tortoise shells come in a multitude of shapes, colours, patterns and sizes. Some have flaps and hinges and some are made in a 3D printer.

South Africa, and in particular the Cape Province, has the richest diversity of tortoises in the world. In our reserve at Jabulani and in the Great Kruger Park region, it’s mostly leopard tortoise that we encounter, as well as some hinged tortoises and the cape and serrated Terrapins (freshwater tortoises).

The leopard tortoise is a member of the not-as-famous Little Five…

They are so-named because of their rosette-patterned shells. Unique to tortoises, they enjoy a cooling swim and because of the shape of their shell, they are the only tortoise that can lift their heads above water. Leopard tortoises have evolved to consume flora specific to their local ecosystem but they spice this up by gnawing on old bones or eating hyena faeces, as this provides valuable, shell-building calcium.

As with elephants, sometimes being bigger is the advantage you’re looking for. The largest tortoise in the world, weighing over 400 kilograms, resides on the Galapagos Islands (the Galápagos giant tortoise). The largest mainland tortoise is the African spurred tortoise, which grows to roughly 100 kilograms and is found in the Sahara desert region. During the hottest periods, they avoid the heat by burrowing up to 15 metres underground and entering a zen-like state, called aestivation. that is similar to hibernation.

Another trick to survival is avoiding detection, which the speckled Cape Tortoise, the smallest tortoise in the world, has mastered. This little reptile calls the Namaqualand area in the Cape Province of South Africa home. They measure between 6 and 10 centimetres in length and are known locally as a padlopers – Afrikaans for “one that walks the path”.

When it comes to increasing their chances of survival in life, tortoises have different ways of climbing to the top of their particular social hierarchies. The Galapagos tortoise asserts its dominance in a ‘head-raising’ competition. Lifting themselves as high as possible on their legs they stretch their heads skywards. The 400-kilogram critter that gets its head the highest, wins.

Forsaking this relatively peaceful method of displaying their superpower, the Angulate tortoise has a special bony projection that it uses to tip over its rivals. Tortoises that land on their shells with feet in the air can generally right themselves, but if unsuccessful, this will end in the death of the tortoise. The Angulate tortoise is reasonably common and is found along the south-western coast of South Africa and is present on both Table Mountain and Robben Island.

Tortoises certainly know what they’re doing, having existed for over 55 million years, as part of a species that is considered to include the oldest land animals in the world.

They take it slow, they persevere, they adapt, but they’re not immune to the threats of the world.

The collection, captivity, donation, selling, import and export of tortoises is illegal under the Nature Conservation Ordination Act. The Geometric Tortoise is one of the rarest land tortoises in the world and is protected under international law prohibiting international trade in the species. Habitat destruction and fragmentation took the Geometric tortoise to the brink of extinction in the 1960s when the last known Cape Town population died out. Fortunately, in 1972 a new population was discovered and it is estimated that between 2000 and 3000 geometric tortoises exist today. Recently land was purchased for a geometric tortoise preserve in the upper Breede Valley of western South Africa.

A lot of work is being done to ensure that this animal will still be with us when our race is run, and they certainly have a right to be there at the end. It seems that 3D printed tortoises are the next step in the battle.

Desert biologist, Tim Shields the co-founder of Hardshell Labs, noticed that ravens were attacking baby tortoises in the California desert. His concept of confusing the ravens with inexpensive, realistic and easily-made 3D printed tortoise replicas strewn across the desert is underway and it is now proposed as a solution to a similar problem with South Africa’s endangered Geometric tortoise. Baboons and mongooses prey on young tortoises as well as digging for the buried eggs. 3D printed replacement shells are also being used on fire-damaged tortoises.

Tortoises have many special adaptations and characteristics that make them fascinating to identify out in the wild but they could also do with us letting them remain wild, safe and protected.

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