ON A WING AND A PRAYER

Between 12 and 20 billion birds migrate out of North America every year for winter destinations in Mexico, Central America and South America. Songbirds such as warblers, vireos, thrushes and flycatchers are leaving now from their breeding grounds in British Columbia for points south. Most of our songbirds stay the winter in the highlands of Mexico but some such as Barn Swallows and Cliff Swallows will not stop until they reach the Amazon River basin.

In recent years, the alarm was rung over the apparent decline of songbirds in North America. Some scientists argued whether the declines were real or inaccuracies in the way data were collected. Others pointed their fingers at habitat destruction in South America, Central America and the Untied States. Still others indicated it was poor weather and cowbird parasitism of nests. Although all of these factors likely plays a role, I discovered that the declines coincide with increased frequency of storms during migration.

The story goes like this: the declines are mostly confined to eastern breeding species and the farther they fly to the winter quarters the greater the decline. Eastern species make an incredible flight of up to 3000 kilometers over the Atlantic before turning back to land in South America. The flights in August, September and October coincide with the time of year that hurricanes rage over the Atlantic. As the number of storms went up, the number of birds counted in North America went down.

If you live near MacKenzie, Whistler, Okanagan Falls, Victoria or Revelstoke, you can join a banding crew. Call CWS biologist Rhonda Millikin at 940-4669 to find out how!

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