The monarch's journey
This annual movement is called migration. They migrate to find food, seek a partner, or in search of warmer weather. One of the most wonderful migrations in nature is that of North American monarch butterfly.
Every autumn, millions of these beautiful insects with fine black and orange wings begin a long and difficult journey. Somehow they manage to travel around 4, 000 kilometres south and find their way to California or Mexico.
A team of scientists led by Professor Eli Shlizerman at the University of Washington has now found the answer. It uses its eyes to measure the position of the sun. These two pieces of information—the time of the day and the position of the sun—allow the butterfly to determine the way to go. Eventually it manages to reach the places where it will spend the winter.
The solution to the mystery of the monarch's amazing ability comes at a time when it is in serious trouble. Its population has crashed by as much as 90% in the last few years. The research on the monarch's behaviour has however led to a greater awareness of this creature. People have been working together to record its migration and make sure that there are enough plants for it to feed on. The more we know about this lovely creature, the more probably it will survive and keep its place in the natural world for a long time to come.
A. Animals migrate for different reasons.
B. However, no one knew how they did this.
C. They've found out that the monarch is able to tell the time of the day.
D. Many animals move from one place to another at certain times of the year.
E. If this works, the number of monarch butterflies might increase once again.
F. They examined monarch butterflies closely and have got first-hand information.
G. Sadly, human activity is the main reason why the number of monarch butterflies is falling.
