Snakes. Vocabulary: scales, brumate, Garter Snake, carnivorous, predators, prey, milky, transparent, cloaca, nourish, hinge.

Transcription

1 Snakes Vocabulary: scales, brumate, Garter Snake, carnivorous, predators, prey, milky, transparent, cloaca, nourish, hinge. S nakes are reptiles. Reptiles have scales and all reptiles except snakes, have claws. They are cold-blooded vertebrates. In the winter in cold climates, they brumate. In Burns Bog there are Garter Snakes. These snakes are not poisonous. If they are scared, they make a very bad smell. They are good swimmers and can hunt for food in ponds and streams. Garter snakes eat birds eggs, tadpoles and small frogs, small mammals, slugs, worms and insects. They are carnivorous and they are predators. They only eat live food. Garter snakes are also prey to raptors like eagles and hawks, and some wading birds like herons. Burns Bog s Sandhill Cranes like to eat snakes too, as do bullfrogs, foxes, raccoons and coyotes. Snakes can eat prey larger than their head because they can unhinge the bottom jaw bone from the top.

2 We can t do that. Our jaws have a hinge that cannot be detached. Look at the picture of a human skull. Can you see where the top and the bottom of the jaw meet? Try to find this place on your own head. Open and close your mouth while you try, you should be able to feel it. You will probably find it just in front of the halfway point between the top and bottom of your ears. Try putting your hands together as though you were making a crocodile s head (1). 1 Now keep the base of your hands together, while opening your hands, as if your crocodile were opening its mouth (2). That s how our jaws are attached - top to bottom. 2 Imagine that your hand crocodile could detach the top jaw from the bottom. Now it can open as wide as its skin will allow (3). 3 attached front and back. A snake s ribs are only attached to their backbone, and not at the front, so that their stomachs can expand if they have eaten something big. Our ribs are

3 Try the same thing that you did with your hands, but with your elbows. Put your elbows together and your fingertips. Try to push them apart so that you make as much space as possible between them. This is a bit like our ribcage, joined at front and back. Now unstick your fingertips. Your ribs can spread much further. Garter snakes do not have fangs poisonous snakes have fangs but they do have teeth. Their teeth curve backwards so that prey cannot wriggle out. Their teeth feel like the Velcro fastenings on some shoes. Snakes do not have eyelids. They have a seethrough scale that protects their eyes. When they are about to shed their skin, these scales turn milky. Snakes shed their skins in one long, snake-shaped piece. But the skin is actually inside out. Try taking off your socks by rolling them down from the top until they come off your feet. Your socks will be inside out, just like a snake s skin. You shed your skin too, but you shed it a few cells at a time, so you never see your human cells. If you shed like a snake, your grown-ups would come into your room one

4 morning and find a whole inside out you-shaped skin. It wouldn t be the same colour as your skin though, it would be transparent. Snakes do have tails! On the underside of their bodies, the scales are much bigger. They have to be able to slither along the ground, and the large scales help them to do this. If you could see the snake s skeleton, you would see that the ribs end but the backbone keeps on going. This is the tail. On the snake s body, there is an opening before the tail starts. This is called the cloaca. The cloaca is where the snake s waste comes out and for the females, where the eggs come out. F emale garter snakes are much bigger than males. Some snakes lay eggs, but garter snakes give birth to live young. This is not the same as when mammals give birth to live young. The way to think about garter snakes is that they make eggs, but they keep them inside their bodies until the snakes are ready to hatch. The eggs do not have hard shells, or even leathery shells, but a soft bag or sac. When mammals produce babies, the baby is inside its mother and attached to her through the umbilical cord. The mother feeds the baby and removes its waste until the baby is ready to be born. Garter snakes, snakes that lay eggs, and birds, all make an egg or egg sac with the baby inside, but it is not attached to the mother, even when it is inside her body. The egg or egg sac has everything it needs to nourish the baby until it hatches.

5 Snake Round-up! Which of these would a Garter Snake eat? Draw something a snake would eat and something it wouldn t eat

6 True (T) or False (F)? 1. Garter Snakes are poor swimmers. 2. Garter Snakes are carnivores. 3. Garter Snakes have teeth. 4. There are Rattlesnakes in Burns Bog. 5. Female Garter Snakes lay eggs. Make up a question for each of these answers 1. A reptile 2. It means it can t control its body temperature from inside. 3. Inside out. 4. No, it has tiny, backwards facing teeth that help to keep its prey in. 5. Because its ribs are only joined to the backbone. 6. Instead they have a see-through scale that protects their eyes. 7. They keep the young inside their body until they are ready to be born. 8. The females. 9. Yes, they do! 10. Brumation.