23rd May: World Turtle Day

Ten facts about turtles and tortoises for World Turtle Day:

1. Turtles are reptiles of the order Testudines or Chelonii, which includes turtles, tortoises and terrapins. In the UK, the word turtle generally means an aquatic creature while the turtles which live on land are called tortoises. In North America, they tend to refer to all members of the family as turtles. In Spain, there is only one word for turtles and tortoises so in Spanish they are essentially called marine turtles or land turtles.
2. The largest type of turtle alive today is the leatherback sea turtle. It can grow to 200 cm (6.6 ft) and can weigh over 900 kg (2,000 lb). There was a turtle alive in the Late Cretaceous period which could reach 4.6 m (15 ft) in length. The smallest turtle is the speckled padloper tortoise of South Africa. It is 8 cm (3.1 in) in length and weighs about 140 g (4.9 oz).
3. The upper shell of the turtle is called the carapace. The lower shell that encases the belly is called the plastron. The two parts are joined at the sides by bony bridges. A turtle's shell is attached to its backbone and ribs, so it can't crawl out of its shell.
4. Most turtle shells are Brown, Black or Olive green, depending on where the turtle lives. There are some species which have red, Orange, Yellow, or Grey markings, spots, lines, or irregular blotches. The eastern painted turtle is particularly colourful with a yellow plastron and a black or olive shell with red markings around the rim.
5. Turtles are thought to see very well at night and good colour vision, from red to near ultraviolet. They have ears, but not ear openings. They're not deaf, but they don't hear well - just well enough to tell if a predator is coming.
6. In some species, the temperature around the egg determines whether it turns into a male or a female. A higher temperature causes a female, a lower temperature causes a male.
7. A group of turtles is known as a bale.
8. Turtles have been to space. In September 1968, the Soviet Union launched the space probe Zond 5 on a mission to orbit the moon and test conditions before sending people up there. The spacecraft carried a number of living passengers, including a pair of Russian tortoises. They made it back to Earth and were rescued along with the other animals. They'd lost 10% of their body weight, had a lot of glycogen and Iron in their liver tissue and some changes in their spleens; but otherwise they were none the worse for it and were still active and eating.
9. Sea turtles have glands near their eyes which produce salty tears. They're not crying, though, they are getting rid of the extra Salt they take in from drinking seawater.
10. Turtles and tortoises can make sounds by by swallowing or forcing air out of their lungs. Some species make some very odd noises, sounding like Chickens clucking, Dogs barking, electric motors whining or a human belch.