The seventh greatest wonder in the world. Really?
The Masai Mara Wildebeest Migration. The annual wildebeest migration in Kenya and Tanzania is arguably the most spectacular natural event in Africa. More than 3 million large mammals have made the vast Masai Mara and Serengeti plains their home, and each summer they migrate, looking for greener pastures. And yes, some call it "the seventh greatest wonder in the world."
Many animal behaviors occur in a regular cycle. Two types of cyclic behaviors are circadian rhythms and migration.
- Circadian rhythms are regular changes in biology or behavior that occur in a 24-hour cycle. In humans, for example, blood pressure and body temperature change in a regular way throughout each 24-hour day.
- Migration refers to seasonal movements of animals from one area to another. Migrants typically travel long distances. Usually, the migrants move to another area in order to find food or mates. Many birds, fish, and insects migrate. Mammals such as whales and caribou migrate as well. Figure below shows the migration route of a bird called a godwit.
Godwit Migration Route. Godwits make this incredibly long journey twice a year. In the fall, they migrate from the Arctic to Antarctica. They make the return flight in the spring.
KQED: Flyways: The Migratory Routes of Birds
For thousands of years and countless generations, migratory birds have flown the same long-distance paths between their breeding and feeding grounds. Understanding the routes these birds take, called flyways, helps conservation efforts and gives scientists better knowledge of global changes, both natural and man-made. See The Great Migration at http://www.kqed.org/quest/television/the-great-migration for additional information.
- Types of animal behavior include cyclic behaviors such as circadian rhythms and migration.
Use this resource to answer the questions that follow.
- Circadian Rhythms Fact Sheet at http://www.nigms.nih.gov/Education/Factsheet_CircadianRhythms.htm.
- What are circadian rhythms?
- What are biological clocks?
- What is the master clock?
- Does the body make and keep its own circadian rhythms?
- Do circadian rhythms have a genetic component?
1. What are circadian rhythms?
2. Why is migration considered a cyclic behavior?