March 9, 2012

A Swift Migration

We're big mystery fans, and when mystery collides with nature, we get very interested. Last week, a birding friend of ours sent us the abstract for a soon to be published article about one of the most mysterious birds in the Rockies – the black swift.  This bird looks like a souped-up swallow, and nests in a smattering of canyons throughout western North America.  Here in Banff National Park, you can see their mossy cup nests in rock pockets in Johnston Canyon.

Swifts eat insects on the wing, so they must migrate to warmer climates every fall. The mystery has to do with where they spend the winter, because they've never been observed in the winter months.  That's right, never!  The black swift is the last North American bird species to have its wintering grounds remain unknown.

Winter habitat in the Amazon rainforest
But no more: researchers in Colorado, using primitive little geolocators attached to a handful of swifts, have figured out where they go. Their winter destination: Brazil.  The swifts from the Colorado Rockies fly 7000 km to the Amazonian rainforest in western Brazil in September and October, and then return to the Rockies in May or June. The geolocators indicate they average between 300 & 400 km per day during migration.

The same research has not been done on swifts in the Canadian Rockies, so who knows if our swifts winter in the same place as their Colorado brethren, but if they do, that would add about 2000 km to the trip!

So we have a mystery solved, but a sense of wonder enhanced.  If you'd like to get a fuller account of the story, try this wonderful post at the earbirding blog: