The Ancient Greeks often predicted the weather by observing the behavior of birds. Although this method may not be as accurate as the evening news, there might just be something to it. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
“It’s a very interesting phenomenon to watch hawks in the fall. An absolutely dull day — if it’s SW winds, dreary, hot, humid, nothing much going on, light winds, awful day — will become an exciting intricate incredibly important migration day, if a cold front passes through.”
Robert DeCandido is the Chief Naturalist of New York City’s Urban Park Rangers. He tells us that hawks can be considered “harbingers of the weather.” In the fall, they respond to changes in air pressure and approaching cold fronts by taking advantage of the winds to fly south.
“A high pressure system is simply something has a higher barometric reading than a low pressure system, and when you bump the two close to one another, the difference in pressure creates wind. Hawks move on the leading edge of these high-pressure systems that we call cold fronts ’cause here the winds are the strongest. And on the leading edges of these high pressure systems the winds are from the NW. They ride with their backs toward the wind, and are pushed toward the coast.”
And if the winds aren’t going in the right direction – well, just fly to to the nearest mountain range.
“If the winds are from the SW, what is happening is that the mountains deflect the currents, much like shooting water from a hose against a wall, the water is deflected upwards, and the birds use these deflection currents along the inland mountain ranges, to head southwest with.”
So keep your eyes to the skies this month. You might just see a flying weather report. Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.