Loggerhead Turtles: Creature Feature

Transcription

1 Loggerhead Turtles: Creature Feature These beautifully colored sea turtles got their name because their oversized head sort of looks like a big log. Within their heads are powerful jaws, which loggerheads use for crushing prey like conchs, horseshoe crabs, and other animals with hard shells. They also eat softer foods like jellyfish, fish, seaweed, and a brown algae called sargassum. Loggerheads live in oceans all over the world, except in the coldest seas. There are more loggerheads in the waters of the United States than any other species of sea turtle. Even so, loggerheads are threatened by many things, including predators, pollution, human development in the turtles' nesting areas, and fishing nets. A female loggerhead sea turtle may travel thousandsof miles to return to the beach where she hatched as a baby to lay her own eggs as an adult. A loggerhead female generally nests every two to three years. After mating, she heads to shore to lay her eggs.

2 On average, she ll lay eggs four times in one nesting season. Each time, she comes ashore and uses her front flippers to clear a spot in dry sand. Then she uses her hind flippers to dig her nesting hole. She positions herself so that her eggs fall gently into the hole as she lays them. Even in the buried nest, the loggerhead eggs may fall prey to hungry raccoons or wild pigs that dig them up. But the eggs that remain undisturbed hatch about 60 days after being laid. Hatchlings dig their way up through the sand toward the surface and wait just underneath the last layer of sand until nightfall. Once cooler temperatures signal that the sun has set, the hatchlings pop the rest of the way out and scurry toward the ocean. On that dangerous journey to the water, they face raccoons once again, as well as crabs, birds, and other predators. Another danger the hatchlings face is what's called disorientation. By instinct, hatchlings head toward the brightest horizon, which is normally the horizon over the sea.

3 But in places where there is human development, like stores or houses, the bright light from these areas draws the turtles away from the sea instead of toward it. Babies that head toward the artificial light usually die. Even when these little loggerheads do make it safely to the ocean, they have to dodge predators in the water, such as sharks and other fish. (In fact, loggerheads have to be on the lookout for sharks their entire lives, no matter how big they get.) Laws prohibit people from harming loggerheads and other sea turtles. Sea turtles live in the water, but they must surface to breathe. And when they do, they can get hit by boats. They also frequently get tangled in fishing nets and drown. So laws require certain nets to have a device that allows sea turtles to escape if they get caught. These devices are called "turtle excluder devices." Many of the beaches where sea turtles nest are protected by law too. People are prohibited from harming either the nesting loggerhead females or their eggs. Loggerhead sea turtles face many challenges, but people can help the species by protecting them in the sea as well as on shore. Text by Catherine D. Hughes

4 Turtle Article FAST FACTS The scientific name of the loggerhead sea turtle is Caretta caretta. A loggerhead sea turtle can live to be more than 50 years old in the wild. The loggerhead sea turtle is a threatened species. This means that they are likely to become an endangered species. There are seven species of sea turtle: loggerhead, leatherback, hawksbill, Kemp's ridley, olive ridley, green, and flatback. All sea turtles are protected by law. An adult loggerhead is about 36 inches (90 centimeters) long. It weighs, on average, about 250 pounds (113 kilograms). Newly hatched loggerheads are about two inches (5 centimeters) long. For the first 7 to 12 years of its life, a young loggerhead lives far out at sea. As hatchlings, they find the ocean currents that will carry them away from shore. Only when older do the sea turtles live or linger in waters nearer shore. Adults often live in bays and estuaries. In addition to natural predators, loggerheads face danger from pollution and trash in the ocean. They are also at risk from boats when they swim near shore, where they re often injured or killed when they collide with boats or are hit by their propellers. The shell on the back of a turtle is called the carapace, while the shell on the belly side is called a plastron. A loggerhead's carapace is heart- shaped, and is reddish- brown. Its plastron is yellowish- brown.

5 Loggerhead Turtles Hazards Adult sea turtles have few natural enemies. Shards are the main predators, especially tiger sharks. Sea turtle eggs and hatchling are eaten by ]ish, dogs, seabirds, raccoons, ghost crabs, and other predators. More than 90 percent of hatchlings are eaten by predators. Only about 1 in 1,000 sea turtles survives to maturity.

6 The most serious dangers to all kinds of sea turtles come from human impact. Nesting areas are scarce because of building construction along beaches. Lights, noise, trash, and activity on beaches can discourage adult females from coming on shore. All of these things also confuse hatchlings, who may accidentally head away from the ocean instead of toward it. Some sea turtles die from eating trash. Leatherbacks often mistake plastic for jellyfish and die when it clogs up their digestive system. Sea turtles can also die from injuries caused by collisions with boats.

7 CCSS Name Date Q.. Consider the argument each author uses to demonstrate the dangers faced by baby loggerhead turtles. A. Video Text Creature Feature A. A. Turtle Article

8 CCSS Name Date Q.. Consider the argument each author uses to demonstrate the dangers faced by baby loggerhead turtles. A. Video Text Perilous journey Ghost crabs and seagulls take their pick. Creature Feature A. A. Even in the buried nest, the loggerhead eggs may fall prey to hungry raccoons or wild pigs that dig them up. Turtle Article Sea turtle eggs are eaten by fish, dogs, seabirds, raccoons, ghost crabs and other predators. For schools of hungry fish, hatchling turtles make a good meal , Gretchen Courtney & Associates, Ltd. They face raccoons once again, as well as crabs, birds, and other predators. Another danger the hatchlings face is what's called disorientation. By instinct, hatchlings head toward the brightest horizon, which is normally the horizon over the sea. But in places where there is human development, like stores or houses, the bright light from these areas draws the turtles away from the sea instead of toward it. Babies that head toward the artificial light usually die. More than 90 percent of hatchings are eaten by predators. Most serious dangers to sea turtles are from human impact. Lights, noise, trash, and activities discourage females from nesting. These things confuse hatchlings who may accidentally head away from the ocean instead of toward it.

9 Planning Strip for Writing Standard #9 Reading Standard #8 Prompt statement Evidence in the text Analysis of support Evidence in the text Analysis of support Evidence in the text Analysis of support Closing statement , Gretchen Courtney & Associates W#9; RI#1 RI#8 Planning Strip for Writing Standard #9 Reading Standard #8 Prompt statement Evidence in the text Analysis of support Evidence in the text Analysis of support Evidence in the text Analysis of support Closing statement W#9; RI#8

10 W#9 RI#8 Name Date Planning Strip Prompt statement Evidence in the text Analysis of support Evidence in the text Constructed Response (Analytical Essay) All three authors make the claim that baby loggerhead turtles face serious dangers. The Creature Feature article provides ample support for this claim by stating that hatchlings usually die when they become disoriented by lights shining in the area where they hatch. In the article, the author states, Another danger the hatchlings face is what's called disorientation. By instinct, hatchlings head toward the brightest horizon, which is normally the horizon over the sea. But in places where there is human development, like stores or houses, the bright light from these areas draws the turtles away from the sea instead of toward it. Babies that head toward the artificial light usually die. The author supports this argument by explaining what the problem is and why it is a problem giving details for both the cause and the effect. Analysis of support , Gretchen Courtney & Associates

11 W#9 RI#8 Name Date Planning Strip Prompt statement Evidence in the text Analysis of support Evidence in the text Analysis of support Constructed Response (Analytical Essay) , Gretchen Courtney & Associates

12 W#9 RI#8 Name Date Planning Strip Evidence in the text Analysis of support Evidence in the text Analysis of support Closing statement , Gretchen Courtney & Associates Constructed Response (Analytical Essay)