Fake chimneys for birds that need vertical hollows to rest

People from New England to Texas are building fake chimneys as nesting spots and migration motels for chimney swifts, little birds that are dwindling in number as nation’s architectural landscape changes. Old factories and schools with huge chimneys are being torn down, and most new houses don’t have chimneys. Many homeowners who do have chimneys are getting m lined with metal for fire safety or capping m to keep animals out.

So conservationists are building big chimney-like birdhouses as summer homes for swifts, which can rest only by using ir toes as grappling hooks on a rough, vertical surface. Several are located around Birmingham, Alabama, where Greg Harber has been watching birds for a dece as chimneys vanish.

It’s disheartening to see how many chimneys have been lost, “but it does give us hope that if we put m up that y will use m,” Harber said as swifts swirled near a real chimney. Because 5.5-inch-long (14-centimeter), torpedo-shaped gray-brown birds sometimes called ”flying cigars ” spend most of ir time flying at up to 35 mph (56 kph), such migration garings offer some of best chances to see m.

Though re are still an estimated 7.7 million ult chimney swifts, scientists estimate ir totals have fallen by more than 70 percent since 1960s, and by more than one-third just over three recent generations of bird — about 16 years. That steep decline prompted International Union for Conservation of Nature to reclassify species last year as vulnerable — step before endangered.

“It fits right in with a lot of or data,” including a recent report that rth America has lost about one-quarter of its birds since 1970, said Jim Bonner, director of Audubon Society of Western Pennsylvania.

It’s unclear how much of chimney swifts’ decline is linked to chimney loss, especially since fake chimneys don’t always get used.

flying insects' swifts eat also appear to be declining. But University of Connecticut professor Margaret Rubega, who is also Connecticut state ornithologist, thinks birds’ decline is likely rooted in South America.

“Chimney swifts are fundamentally a South American bird that visits rth America for four months,” she said.

Rubega said a big problem is that scientists have only a few reports of small numbers of chimney swifts in upper Amazon Basin, so y don’t really kw where y winter, let alone what may be happening to m re.

Although three less numerous western species of swifts also migrate to Central or South America, ir numbers are stable or even increasing slightly.

When swifts migrate, chittering clouds of birds circle big school or factory chimneys at dusk and drop into opening a few at a time in what birdwatchers call a “swiftno.”

Birmingham still has about 30 big chimneys were hundreds, even thousands, of migrating swifts rest en route to South America, said Lianne Koczur, Alabama Audubon’s science and conservation director. “But if you consider that one or two or three are being lost every year, it doesn’t take very long” to lose m all, she said.

Most fake chimneys are wooden and 8 to 12 feet (2.4 to 3.7 meters) tall, designed to replace home and small industrial chimneys used as nesting spots. re’s only one nest per chimney, even if several ults roost re.

Bonner said Audubon Society of Western Pennsylvania has built or helped with about 150 towers in Pennsylvania, including 100 in Allegheny County’s nine parks. Nests get built in about half of 40 oldest structures and data isn’t yet available for many, Bonner said.

George and Paul Kyle, couple credited with starting current surge of tower building, said y’ve put up more than 100 nesting towers in Central Texas, and nearly all are occupied. Eighty percent of those built before birds’ March arrival get nests ir first year, y said in an email. nests are me of loosely woven twigs cemented to each or and chimney with birds’ sticky saliva.

“If you cup your hand and put that up against a wall, you’re t out that far” on size and shape, Bonner said.

A couple of 20-foot-tall (6.1-meter) towers regularly host hundreds of migrating swifts, y wrote.

However, larger towers designed for migrating flocks have h little success at attracting m. Swifts have nested in a 30-foot brick tower finished in early 2015 in Raleigh, rth Carolina, but migrating birds have dropped in only in response to a recording of a flock’s twittering chatter, said John Gerwin, a naturalist at rth Carolina Museum of Natural Sciences. Up to 75 birds have roosted re, he said, “but y don’t come back unless we’re re to do playback.”