MEXICO: THE MYSTERIOUS MONARCH
During the summer months, the monarch lives in the northern part of the United States and Canada. At the end of the summer, they begin their southward migration to Mexico. They cannot fly when the temperature drops below 55 degrees. It takes them about 25 days for the monarch to travel the distance. They go 80-100 miles a day. They can fly up to 20 mph at altitudes up to 10,000 feet. The nectar from marigolds, foxgloves, and buttercups gives them energy.
By November 1, all of the monarchs have arrived to the top of the same mountain in Angangueo, Mexico. The oyamel fir tree supports 30-40 million butterflies at once. They spend the winter here and mate on the spring return north. These fragile creatures have a life span of only a few months, therefore, the monarchs who return north are not the same ones that made the same trip the year before. Yet, they return to the same exact spot. How they know the way is one of the great mysteries of nature.
Monarch butterflies are often tagged and tracked to see how long their flight takes.
1. One tagged butterfly takes 25 days to go 1800 miles. If it
went 18 mph, how many hours did it fly each day?
2. Another tagged butterfly travels 90 miles a day to go the 1800 miles. How many days does it take? How fast is it flying if it flies 6 hours a day?
3. The fir tree that supports the 30-40 million butterflies actually bends under the weight. Write the number that is halfway between 30 and 40 million. If each butterfly weighed .5 ounce, what would be the weight of all of the butterflies on the tree using this number? How would you find out how many tons this is?
4. One day after mating, the adult female begins laying eggs. She deposits only on milkweed plants and only 1 egg per leaf. She does this for 4 weeks and lays about 500 eggs. At this rate, about how many eggs does she lay in a day? If 54,000 female butterflies lay 500 eggs apiece, how many eggs is this? If there are 30,000,000 butterflies, what is the least amount of females that could have laid the eggs?
5. The egg hatches a caterpillar in 3-5 days. Three weeks after
hatching, the caterpillar transforms into a chrysalis. Twenty-four
hours later it has shed its skin and produces a cuticle which hardens.
About a week later the casing is cracked and a butterfly emerges.
About how many days is it from the hatching of the caterpillar to the emergence
of the butterfly?