Laura Erickson's For the Birds

(Recording of a Northern Oriole)

The only thing more interesting than bird migration is watching it first hand. Keeping lists of the arrival dates of migrants can be a valuable tool in learning the sequence of migration, and is also a wonderful way of keeping sane during a cold spring—when you realize that even in the best years orioles don’t come back until about May 10, it helps you keep your perspective when we get a snowstorm at the end of April.

Ancient people sometimes watched birds flying across the full moon, and concluded that the birds were actually flying to the moon. By the 1900’s ornithologists were far more sophisticated, and in the 1940’s a scientist named George Lowery developed a technique of quantifying the magnitude of migration by counting with a telescope the birds going past the full moon, and then extrapolating the number that must be crossing the whole sky. If you want to try that technique, tonight’s full moon may give you the opportunity.

High tech ornithologists now track birds using radar, and occasionally affix radio transmitters to migrants in hopes of picking up the signal as the bird travels. Sometimes migrants are observed from aircraft, and soon a Bald Eagle at the Raptor Rehabilitation center in St. Paul will be tracked by a NASA satellite.

But probably the most satisfying observations of migration are made by simply looking skyward at a V of geese winging by, or sitting outside on a pleasant evening listening to the call notes of migrants passing over. Birds don’t come equipped with headlights, and so night migrants have to make continuous sounds to avoid mid-air collisions with one another. With experience it is possible to identify many of these birds by their call notes alone.

Setting up a bird feeder this time of year is another enjoyable way of observing migration. One day your feeder is crowded with juncoes, and the next day half of them have disappeared and a Chipping Sparrow is suddenly there. Rose-breasted Grosbeaks come in on a warm front, and during a cold rain the first Cape May Warbler alights on the orange you set out for the orioles. Almost every day brings at least one new species from the south, as another disappears to the north.

As with most of the year, sunflower seed is the feed of choice if you only set out one thing. But during migration a handful of mixed bird seed or cracked corn spread on the ground will attract a myriad of sparrows, close enough for you to practice your identification skills. An orange cut in half and tied to a tree or stuck in a special feeder made for that purpose will lure orioles from the sky. Sugar water will please hummingbirds, and also orioles, rose-breasted grosbeaks, catbirds, and some warblers if its set in a shallow bowl instead of a hummingbird feeder. Grape jelly will also attract these species. Jelly tastes good to an oriole throughout the summer, unlike oranges, which they always stop eating by June. Suet, peanuts, and other fare round out the smorgasbord, and widen the possibilities for observation.

Watching migrants at a feeder can redeem even the most miserable spring day, and can widen your world to include some of the richest wonders of the natural world.

(Recording of a Northern Oriole)

This is Laura Erickson, and this program has been “For the Birds.”