Sky & Telescope October 1998 [antikvár]

SpectrumBy the Light of the MoonIn early autumn, as the workday ends, this New Englander begins to twitch when he knows that northerly winds will blow across the face of a nearly full Moon. My anticipation grows as I quickly eat dinner and set up my little spotting scope. Now I'm ready for Moon-watching, but not the kind you might think.On such nights the Moon forms a mere backdrop for fleeting silhouettes birds heading south during their annual migration. On a really good night scores of critters can be glimpsed in an hour.It's humbling to see such a button of energy winging it. That's especially so when you realize you caught an ounce-size waif for only a second during a flight that might last many hours. And many such hops will be needed before the bird reaches its wintering grounds, perhaps deep in South America.Moonwatching actually a technical term used by ornithologists was once employed for research. (It preceded, and shouldn't be confused with. Project Moonwatch, which came on the scene to track artificial satellites at the dawn of the Space Age.) Before the widespread use of radar, those fleeting silhouettes provided the only means for knowing what nocturnal routes migrating birds were taking between their summertime boreal homes and wintertime austral ones. Moonwatching's most celebrated discovery answered a long-standing question: Do birds migrate nonstop for hundreds of miles across the Gulf of Mexico? They do.Birds, the Moon, and 1 teamed up again last April. Long before dawn one morning 1 inched my car onto the shoulder of a dirt track near Elkhart, Kansas. Our natural satellite, a cooling ember near the horizon, dropped through an oddly shaped cloud that first surrounded its disk with rings like Saturn's and later crowned it with a white sombrero.Across the nighttime prairie floated disparate clucks and cackles left, right; near, far. Slowly the sounds melded onto a single stage from which arose a cacophony of bird music, albeit sotto voce. The crenelated lunar disk, now blood red and joined by the merest blush of dawn, cast just enough light to allow me to distinguish gray ghosts scampering amid grayer sagebrush. The performers were lesser prairie chickens, one of the rarest endemic birds in North America.As dawn took command, "real" birds could be seen frenetically dancing, displaying, and fighting to impress prospective mates. But I'll most fondly remember the scene when ghosts talked to ghosts while bathing in somber moonlight.P.S. Don't miss the story beginning on page 112 it's for the birds too!