Dragonflies – Migration

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ambience river ecosystem (Basherkill), dragonfly wings

It’s well known that there are birds and butterflies that migrate to warmer climates in the winter. But there are other creatures that fly south every year as well. I’m Jim Metzner, and this is the Pulse of the Planet.

“They’re probably migrating to find food, because all dragonflies depend on feeding on other insects. During the winter in the northern US and southern Canada, there would be no insects around for the adults to eat.”

Mike May is an entomologist at Rutgers University. He says that most dragonflies don’t migrate. They spend their winters underwater in an immature stage in a state much like hibernation, where they don’t have to eat much to survive. But there are about a dozen species of dragonflies – all particularly good fliers – that have adapted a different strategy.

“They all migrate by flying southward in the Fall. And what we presume are their offspring come northward in the spring. The best known migrant is a dragonfly called the Common Green Darner. They have an interesting life cycle. Individuals living in a particular pond will emerge late in the summer and begin to fly south probably almost as soon as they emerge from their aquatic immature stage. We think that they fly as far as the southern United States, or possibly even further to Mexico. It appears likely that they then lay their eggs in ponds and lakes in those southern areas and their offspring emerge after a couple of months, developing as immatures underwater. They’ll crawl up on plant stems, break out of their hard outer covering and then fly north.”

We’ll hear more on dragonflies in future programs. Pulse of the Planet is made possible by the National Science Foundation.

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Dragonflies - Migration

It's a rare event, but a grand sight to behold - thousands upon thousands of dragonflies.
Air Date:09/06/2011
Scientist:
Transcript:

music
ambience river ecosystem (Basherkill), dragonfly wings

It's well known that there are birds and butterflies that migrate to warmer climates in the winter. But there are other creatures that fly south every year as well. I'm Jim Metzner, and this is the Pulse of the Planet.

"They're probably migrating to find food, because all dragonflies depend on feeding on other insects. During the winter in the northern US and southern Canada, there would be no insects around for the adults to eat."

Mike May is an entomologist at Rutgers University. He says that most dragonflies don't migrate. They spend their winters underwater in an immature stage in a state much like hibernation, where they don't have to eat much to survive. But there are about a dozen species of dragonflies - all particularly good fliers - that have adapted a different strategy.

"They all migrate by flying southward in the Fall. And what we presume are their offspring come northward in the spring. The best known migrant is a dragonfly called the Common Green Darner. They have an interesting life cycle. Individuals living in a particular pond will emerge late in the summer and begin to fly south probably almost as soon as they emerge from their aquatic immature stage. We think that they fly as far as the southern United States, or possibly even further to Mexico. It appears likely that they then lay their eggs in ponds and lakes in those southern areas and their offspring emerge after a couple of months, developing as immatures underwater. They'll crawl up on plant stems, break out of their hard outer covering and then fly north."

We'll hear more on dragonflies in future programs. Pulse of the Planet is made possible by the National Science Foundation.

music