Turtle Hurdles

Background Information
When it's time for a female turtle to lay eggs, she will come out of the water up onto a beach. She will crawl many meters up the sand, sometimes all the way up under some protective shrubs or bushes. There she will use her flippers to hollow out a depression in the sand where she will deposit her eggs, up to 100 at a time. Each nest full is called a clutch. When all the eggs have been laid, she will turn around, use her flippers to bury them all and return to the sea, never to know if her babies survive.

It's not easy being a baby turtle! Once they are ready to hatch (about 38 days after laying for hawksbill turtles) they need to get out of the shell. They have a small hook-like projection on their snouts called a caruncle that helps them slit open the leathery shell. This is only the beginning, however, as they are still buried beneath the ½ meter of sand their mothers placed over the nest to protect them. They must use their tiny flippers to dig their way out. This is definitely a group effort as the hatchlings on top pull down the sand and the ones on the bottom stamp it down. This process may take several days. Once they have uncovered themselves, they must head for the water across the large expanse of sand.

Nearly all hatchlings emerge at night, when the threat of bird predation is almost nonexistant and they won’t get overheated from the sun as they make their way to the water. In a natural situation, they use the reflection of the light from the moon and the stars on the water to help them find their way. As they cross the sand, they are threatened by many predators – raccoons, seagulls, ghost crabs, even dogs. Once they get to the water, there is still no guarantee of their safety. The ocean is full of predators just waiting to feast on young turtles. In fact, of every 100 eggs laid by a female turtle, on average only one will live to be an adult.

There are many factors threatening the existence of most marine turtles. Human encroachment on the beaches disturbs their nesting behavior and destroys their habitat and ATV (all terrain vehicle) use destroys many nests and kills many young. One surprising threat is the use of spotlights or other bright lighting by people that live along the shore. Because baby turtles depend on the light to determine which direction to crawl, the bright lights confuse them and cause them to actually move away from the water. Once in the water, water pollution and plastic bags that they mistake for food threaten young and adult turtles.

Overview
This lesson uses a relay race to impress upon students the difficulty baby turtles have trying to survive.

Objectives
Students will
     Be able to describe the life cycle of marine turtles
     Name 3 factors threatening the survival of turtles
     Suggest 2 things they can do to help protect turtle species

Materials
An outdoor or large indoor space
Meter sticks or measuring tape

Procedure
1. Tell the students to imagine a large, deserted beach. Suddenly, in one of waves comes a large hawksbill turtle. She crawls up the sand and under a protective mangrove where she starts to dig a large hole. When she is satisfied with the hole, she deposits her eggs, up to 100 in every clutch, buries them and returns to the sea.
2. Ask what happens when the babies are ready to hatch? What has to happen first? (they have to get out of the shell) Next? (they need to unbury themselves). Then they need to find the water. But baby turtles are little. All they can see is a never-ending expanse of sand around them. How do they find the water? Let the students brainstorm and then explain that they use the reflection of light on the water to guide them. Explain that people with houses on the beach that have big spotlights are a problem for the baby turtles. Why would this be? Do they think it's easy being a baby turtle? They are going to find out – they are going to have a turtle race!
3. Turtle races are a relay. The class can be divided into two or more teams. Smaller groups finish faster. Pick a point at the edge of the space and have two or three students measure a course 100 meters long. Each group lines up at one end of the course, one student behind the other, one arm's length apart and with their legs apart. Meter sticks or one member of each team (someone who doesn't want to run!) should mark the other end of the 100 meter course. That person will be the "leader".
4. The race starts from the back of the line – the last person is really first. When the go is given, the last person needs to crawl through everyone's legs, simulating the baby turtle crawling up out of the nest. As an alternative for older students, they can weave in and out around their team members.
5. Next, they need to run the hundred meters to the leader. There they need to bend down and spin around 5 times. The leader should count this out loud. This represents the turtles' racing toward the water and getting confused by the lights.
6. Last, they run back to the line and place themselves in front of the line with their legs apart. As each person gets back to the line, the next at the back starts through the legs of the team members. When everyone in the line has gone through once, the whole team sits down. They are the winners!
7. When all the teams have finished, gather them together and discuss their experience. Was it easy? Explain the problems with predators on land and in the ocean. Out of every 100 eggs that are laid, how many do they guess grow up to be adult turtles? Explain that only 1 in 100 survives to adulthood.
8. Discuss some of the human influences that are affecting the survival of the turtles. What are some things that students can do to help protect turtles? (Be careful with plastics, research environmental laws and write support letters to congressmen and senators, don't pollute water, etc.)

Assessment
Ask students to describe each step of the baby turtles' hatching and to explain the dangers facing it at each step.

Resource Links:
Hawksbill Turtles: www.sonic.net/~mk/work/turtle.html
Sea Turtles: http://www.dnr.state.md.us/wildlife/turtles.html
Nova Scotia Turtles: http://museum.gov.ns.ca/mnh/nature/turtles/index.htm