The Alligator snapping turtle, Macrochelys temminckii, the largest freshwater turtle in North America, has been reclassified as three species in a paper published by Travis Thomas and other researchers in April’s edition of Zootaxa. Just like that, we have two more species of turtle overnight!
The huge, dinosaur-like turtles were classed as a ‘Vulnerable’ species, a category of less concern than ‘Endangered’, for species that aren’t gonna disappear soon, but that we need to keep on eye on.
But with the reclassification, each of the three the newly-minted species are much fewer in number than the old one, raising concern for the survival of the species. They are sometimes captured in the wild to make turtle soup.
Researchers did genetic analysis of alligator snapping turtles from different rivers. Their habitat spans rivers hundreds of miles apart in the southern USA.
They discovered that the turtles from rivers have different genetic markers, and concluded that they have probably been isolated for millions of years.
Some of your readers have new, young Hermann’s tortoises and are wondering how big they’re gonna get. This is a more complex question than it seems, as there are several subspecies of Hermann’s tortoises and they differ considerably in size.
The main two subspecies are the eastern subspecies, Testudo hermanni boettgeri, and the western Testudo hermanni hermanni. Of the two, the eastern is considerably bigger, growing to about 11 inches (28cm) in carapace length and 6-9lb (3-4kg) in weight. The western ones, on the other hands, only get to be about 7.5 inches (18cm), but can be much smaller.
The situation is further complicated by the fact that there are other subspecies, including the Balkan Testudo hermanni hercegovinensis. This is comparable in size to the eastern subspecies. Furthermore, the subspecies are interbred now, especially in the pet industry, so it’s not always clear which species your dealing with, which might make the size of your individual tortoise a bit of a wild card.
In all subspecies, the female is slightly larger, maybe 10% larger.
The gopher tortoise (Gopherus polyphemus), native to Florida, is a fascinating species of wild tortoise. They are grazing tortoises, adapted to live in sandy longleaf savannahs.
The most interesting thing about them, though, is their burrows. They dig burrows up to 15 meters long and 3 meters deep. Their native habitats end up crisscrossed with these burrows, which form an integral part of the ecosystem. The burrows dug by the gopher tortoise ends up serving as a shelter to all kinds of other animals too, from snakes to frogs to the bizarre Burrowing Owl. In fact, some ecologists believe that the burrows dug by the gopher tortoise are useful to over 400 other species! Not only do animal species use them, but plants do as well. Some research indicates that the presence of gopher tortoise burrows increases the amount of vegetation that grows, possibly by providing underground irrigation channels.
A lot of our readers have been asking about their tortoises skin peeling. Some owners see whitish flakes of skin and are concerned that their tortoises have developed a skin condition. Others are enquiring about whether tortoises shed a coat of skin like some other reptiles (e.g. lizards) do.
Tortoises do shed their skin. This happens at a faster rate when they are growing. The old skin is replaced with new, and peels off in white flakes. (However, peeling skin with any sign of inflammation, discoloration or bleeding is probably something else.)
Tortoises don’t shed their skin in as dramatic a fashion as some other reptiles.
Skin-shedding is a perfectly normal and harmless process that will happen just fine on its own. However, you may like to speed it along by giving your tortoise a bath in lukewarm water and a gentle scrub with an old toothbrush. This helps remove the old, dead skin, giving the tortoise’s skin a fresher feel (my girlfriend tells me this is called ‘exfoliating’ in the beauty industry).
Tortoises can basically be divided up into three groups: tropical, Mediterranean and grazing. These three groupings have broadly different diets, but it should be emphasized that such a broad consideration is only a starting point for deciding what to feed your pet. Expert keepers will adapt these basic dietary groupings for particular species, and even for different weather conditions, ages and seasons.
To help you visualize the diet of these tortoises, we find it helpful to show word clouds. The size of the words in each picture is proportional to the quantity of that food type the animal should be given.
There are four Mediterranean tortoises: the Hermann tortoise, the Horsfield’s tortoise, the Kleinmann’s tortoise and the Greek tortoise.
Tropical tortoises are omnivores native to rainforest regions of the world. These include the red-footed tortoise, the yellow-footed tortoise, the Asian forest tortoise and dozens of other species that are rarely kept as pets.
These herbivorous tortoises subsist on a diet mostly of grass, being adapted to arid grassland regions. Species include the Leopard tortoise, the African Sulcata tortoise, and the Indian star tortoise.
Brendon Grimshaw, an 86-year-old Briton, lives on a tropical island in the Seychelles, with no other human inhabitants, but 120 giant tortoises. That’s at least 15 tons of tortoise! I’ve heard of some keepers with big tortoise collections before, but this takes the prize.
He bought the island in 1962 for just £8000.
Commercial incubators for tortoise eggs can cost you $100 or more, but here is a simple way to make an incubator for less than $20.
You will need an empty plastic bottle, preferably one with a wide mouth. Go to a pet shop and get a cheap aquarium heater. These heaters cost about $15 and can be set to any desired temperature.
Fill the bottle with water and put the aquarium heater inside. Place the bottle with heater inside some sort of insulated box. One way to construct a good insulated box is to place a small plastic crate inside a larger box, and fill the space between the two boxes with styrofoam.
Voilá! The temperature in this incubator will remain steady and the humidity will remain high because of the warm water. You may have to top up the water every now and then. The beauty of this method is that the water itself helps passively stabilize the temperature through the thermal mass effect.
Some new owners get concerned when they see their tortoise leaving a white, powdery substance in the enclosure. Many people have asked whether this is a sign of some disease, and there is a rumour going around that this powdery urine is the result of dehydration.
In fact, it is quite normal and healthy for a tortoise to urinate white powder. It is concentrated uric acid. Tortoises, particularly those adapted to arid climates, urinate solid matter instead of liquid in order to conserve water. Whereas most animals eliminate the by-products of protein metabolism using urea, arid-climate tortoises perform the same function with uric acid. This allows them to use less water in the process, which is important for their survival in the wild.
If these white leavings are appearing every day, though, it might indicate a problem. They are the end result of protein metabolism, and, as we explain in the article on tortoise nutrition, the amount of protein you give should be modest. Another reason for excessive production of white powder is dehydration. Dehydration leads to accumulation of uric acid, and this can cause problems in the kidneys and bladder if not taken care of.
So, some white powder in the cage is fine, but if it is every day, take this as an early-warning sign and take another look at your hydration and diet strategy.