If they leave too early, they will encounter frozen conditions and find less to eat during the migration. If they leave too late, they won't have enough time to raise their young before fall blizzards arrive. An animal's very survival depends on being in the right place at the right time. Internal or biological clocks are found in all living things, including humans. They signal when to wake, when to sleep, when to forage, when to fly.
Animals detect sunlight changes during the seasons and set their internal clocks.
The changing photoperiod, or amount of daylight hours between sunrise and sunset, governs the annual rhythms of life throughout nature. Test Your Biological Clock Cover all the clocks in the classroom. At the end of the day, discuss results. With whooper numbers down this year, experts are happy to say that an escorted migration for whoopers looks like a real possibility for 2001. This new flock will migrate between Wisconsin and Florida.