Today is National Butterfly and Hummingbird Day in the U.S. And both of these creatures are migrating now -- two of our popular FB posts recently showed how they can be tracked on radar but before NEXRAD we used the moon! From a classic Sandra Steingraber essay: Before radar, researchers estimated the intensity of songbird migration by moonwatching. This was a quaint but highly skilled practice that involved counting the number of birds seen flying across the face of the full moon. It required clear skies, a telescope, and elaborate calculations to account for angles of entry, altitude, and percentage of night sky occupied by moon. Moonwatchers made fantastical claims: two hundred bird silhouettes crossing the lunar window in an hour meant that three million migrants had passed by. Which meant that billions of birds were on the move during particular nights of the year. There was a lot of skepticism about these extrapolations until they were confirmed by radar operators. Read her whole beautiful essay at the Orion site, drawing parallels between her pregnancy and the movement of birds.
Posted on: Fri, 03 Oct 2014 17:25:43 +0000
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