The Back Porch

Migration

There They Go Again

This story is featured in Montana Outdoors November-December 2012 issue

Those little tufts of bright feathers that sang beautiful songs and entertained us in spring and early summer are headed south. Fast.

It’s songbird migration time. In fact, some, like the western kingbird and northern oriole, will leave north-central Montana while it’s technically still summer, in late August and early September.

Other birds won’t abandon their northern homes until severe weather pushes them south, though “south” may be just from Canada to Montana. To this group add the common redpoll and Bohemian waxwing.

Most migrants, like the American gold­finch and common yellowthroat, head south from mid-September though October.

The migration puzzle has fascinated humans forever.

In the Middle Ages, a belief took hold that birds flew to the moon for the winter. (They don’t, in case you wondered.)

Others thought that birds such as swallows and swifts hibernated in caves. Not a crazy notion, really. Bats do it, why not birds? But also not true.

Some folks believed hummingbirds rode on the backs of geese. Hummers are so small, the argument went, there’s no way they could fly very far on their own. They must hitch a ride on the backs of geese. Though the myth is not true, apparently some folks still believe it.

Birds evolved to migrate because it works. Species traveling from northern latitudes to warmer winter climates are able to live in two different regions when each provides favorable conditions.

Migration is tough. According to one estimate, more than half the small land birds of the Northern Hemisphere never return from their southbound migration. Among the risks: exposure, exhaustion, and physical dangers both natural, like hurricanes, and manmade, such as skyscrapers.

Many of us have heard the sickening thud of a bird flying into a window at home. Now think bigger, say, New York City bigger.New York or almost any metropolis on the Eastern Seaboard lies along a major songbird migration route. All of those big cities have big buildings with lots and lots of glass, which can be a perfect mirror in certain lighting. To migrating birds, the buildings sometimes look exactly like the sky.

The National Audubon Society calculates that 90,000 birds are killed each year in New York City by flying into buildings. That estimate, by the way, comes from volunteers picking up dead birds each morning during the fall migration at the base of the city’s glass towers.

Not all birds migrate. Magpies and house sparrows spend their summers and winters in the same spot. And all of our upland game birds, such as pheasants and mountain grouse, stay put, mostly just moving about within their habitat.

Birds that do migrate, especially those flying thousands of miles, accomplish feats that boggle the mind. Think of it: A human who wants to complete a 26-mile marathon typically trains for months or longer and usually goes over the course before the race.

Meanwhile, a western tanager that hatches and learns to fly in the Gallatin Valley south of Bozeman will, just a month or so later, journey 2,400 miles south to Guatemala, navigating by landmarks it has never before seen.

Once again, which is the superior species? .Bear bullet

Bruce Auchly manages the regional Information and Education Program in Great Falls.

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