Evidence of How High Monarchs Can Fly

Here are the types of observation that have helped scientists better understand how high migrating monarchs can fly. Do any of these surprise you? What do they make you wonder?

A pair of binoculars has two numbers. The first indicates how many times it magnifies. So with 7x30 binoculars, objects look 7 times larger.
Binoculars: With most binoculars, objects look 7 to 10 times larger than with your bare eyes. Here are examples where monarchs were seen with the help of binoculars:

Glider pilot observations: Monarchs were spotted soaring at 4,900 ft in Nebraska along with corn husks! In Massachusetts, they were seen soaring at 4,500 ft at about 19 miles per hour. (Source: Dr. David Gibo)

Commercial pilots: They have seen monarchs as high as 10,000 to 13,000 feet. That's more than 2 miles (3,000 to 4000 meters) above the earth's surface! (Source: Monarch Watch.)

This "vertical-looking radar" device can detect layers of insects high in the sky!
Radar (other insects): Scientists use radar to track the number and behavior of insects that could help or hurt farm crops. This scientist was surprised to discover dense "layers" of insects at different altitudes! Most were found at 740 meters (2,428 feet); but above 800 meters, the numbers dropped dramatically. (Source: Insect Population Dynamics)

Dr. Calvert's Q & A: Learn what Journey North's Dr. Bill Calvert has to say about this phenomenon! >>


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