A "guest blog" on Fall Migration!

Hi everyone,

I received this informative essay from a 13-year old homeschooler, and thought you might find it interesting and useful.  Indeed, I've invited Sawyer to be an occasional "guest blogger," and I hope that she will share her experiences participaing in BirdSleuth and Project FeederWatch with us this coming season!

Some potentially new vocabulary for you to explore with your child:
  • flyway
  • migrate
  • photoreceptors
  • molt
Activities for you to try: 
  • Find out which species of birds are migrating in your neighborhood this season (visit http://www.ebird.org/ and "view and explore data")
  • Listen for birds during the day: what bird species are calling in your area?  Go out on a clear night and see if you can hear birds or other nocturnal animals.
Jennifer Fee
Cornell Lab of Ornithology, Education Program

The Fall Migration

At least once every fall, my family goes to Hawk Hill, just north of the Golden Gate Bridge in the Marin Headlands. Hawk Hill is on the Pacific Flyway, one of the four flyways which pass over North America: the Atlantic, Pacific, Mississippi, and Central. A flyway is basically a highway for the birds. They fly along that stretch of land (or water) while migrating. A good map of the four flyways is at http://www.birdnature.com/flyways.html. 

Did you know that the diet of a songbird changes when it comes time to migrate? In the fall, as the days shorten, the change in daylight triggers photoreceptors in a songbird's brain. The photoreceptors cause their diet to change from 90% insects to 90% fruit and grain. The reason is that fruit and grain make a lighter, more energy efficient fat. The photoreceptors also make the birds jumpy and molt.

One surprising thing I learned is that, at migration time, birds mostly fly by night and rest by day. Some even fly 24/7, with no rest at all. They fly over our heads as we sleep, a silent, nocturnal hoard. Actually, they aren't silent at all. If we were to sleep with our windows open, we would hear them. But sometimes it is too cold to do that, so a researcher named Bill Evans has come up with a way to hear them without opening a window. He records the night migration using a microphone attached to a computer. (Note from Jen: Here at Cornell Lab, we also work on "night migration" using sound recording learn more about the kinds and numbers of birds overhead.  To learn more about work on this topic, visit http://www.birds.cornell.edu/Publications/Birdscope/Summer1994/brp94083.htm.)

In my next blog entry, I'll tell you about what I'm learning about how songbird's migrate from the book Songbird Journeys by Miyoko Chu. Until next time, Happy Birding!

Sawyer B.
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