May 13 2013
Ever since they returned from Peru last month the chimney swifts have been busy courting in the air.
You’ll often see a trio chittering loudly, flying fast, and turning sharply in unison. Studies have shown that the lead bird is usually a female and her followers are male. Their chases last more than five minutes, more time than I usually can spare to watch them.
After they form pairs the couples continue to fly together. Sometimes as they sail by the rear bird will raise his wings in a V. This happens more often after pair formation so scientists believe it’s part of pair bonding. I’ve seen pigeons do it too, without the “chitter.”
Chimney swifts have other amazing flight abilities. Did you know that…
- They fly almost constantly and only stop to roost or nest.
- They bathe on the wing by smacking their bellies against the water’s surface and shaking it off.
- If the opening is wide enough they can fly headfirst into a chimney and turn upright in mid air to cling to the chimney wall.
- They fly into narrow chimneys tail first.
- Their mean air speed is 29-30 miles per hour.
- They can fly at an altitude of 7,000 feet on the warm air rising ahead of a cold front.
It’s a joy to watch a bird that flies so well.
(photo by Jeff Davis)