The Chimney Swift: Amazing Acrobat of

Amazing Acrobat of the Skies THE CHIMNEY SWIFT: Catherine Greenleaf - Lyme, NH

It’s time for a confession. My husband and I are ardent fans of the Chimney Swift. We always look forward to the cooler weather that comes with fall because it’s the time of year we get to watch the southward migration of this mysterious and fascinating bird. By the end of summer, breeding season has ended and the Chimney Swifts are readying themselves for their long and grueling flight back to the headwaters of the Amazon in Brazil. This is when my husband and I join local birding groups and travel to various locations throughout New England to witness in awe what can only be described as an incredible spectacle. Against the orange and pink hues of the setting sun at dusk fly thousands of Chimney Swifts, swirling together in the air like a black tornado. Then, in a magical feat of synchronization, they funnel straight down, single-file into smokestacks, water towers, or abandoned air shafts to roost for the night.

LIFE CYCLE OF THE CHIMNEY SWIFT

But let’s go back to where the breeding season begins. By the first of May, Chimney Swifts have migrated thousands of miles from South America and you can hear their happy chatter in the air overhead as they arrive in New England.

These birds are often mistaken for bats because they are small (5-6 inches long), black to dark greyish brown in color, and sport a short and square tail. The Chimney Swift is social and gregarious and prefers to hunt for insects in small packs of up to 12 birds.

A skilled aerial acrobat, the Chimney Swift does everything from the air. When building its nest, the Chimney Swift grabs small twigs off the tops of trees and breaks them in half with its feet – while airborne. This species can swoop down to a pond and scoop water into its beak to drink. It lowers its body into water mid-flight to take a bath and spends the entire day snapping thousands of insects out of the sky with its wide mouth.

Chimney Swifts are ravenous insectivores. A family of five Chimney Swifts can eat up to 12,000 insects a day, according to the Cornell Lab of Ornithology.

This bird’s anatomy is quite different from most songbirds. It does not have the leg structure required to perch upright on branches and instead uses its hooked toes to cling to vertical surfaces like the brick and mortar of chimneys.

Chimney Swifts build their nests inside chimneys. For centuries, this species nested in the hollows of dead trees. But due to wide-scale deforestation, most large, dead trees have disappeared, forcing the birds to adapt by using chimneys.

There is no need for alarm should you discover Chimney Swifts nesting in your chimney. Merely refrain from use, close the damper and delay inspection or cleaning until after migration occurs in the fall. Chimney Swifts are protected by the Migratory Bird Treaty Act and it is a federal crime to capture, injure or remove the birds or their eggs. If you have concerns, you can always contact your local wildlife rehabilitator for assistance. It is wiser to focus on the benefits, as the lucky homeowner with a nest in their chimney enjoys a mosquito-free yard all summer long.

Chimney Swifts are gracious tenants and do not normally cause any damage, as only one family of 3-7 birds will take up residence in a single chimney, according to the National Audubon Society. The parents build a shallow pocket of sticks inside chimney walls, using their sticky saliva as a glue to keep the nest affixed to the wall. The female lays 3-5 eggs, and fledglings are ready to fly in 30 days. Research by avian scientists is now showing that an unmated female will often help a breeding pair rear its young.

Once the youngsters are grown, the Chimney Swifts begin their migration back to South America, which usually occurs between the end of August and the beginning of October.

Chimney Swift numbers are flagging due to climate change and habitat loss and could use some help. The Cornell Lab of Ornithology recommends the measures below:

HOW TO HELP CHIMNEY SWIFTS

• Preserve your existing chimney to allow entry by Chimney Swifts. • Refrain from the use of pesticides on your property, which can poison aerial insectivores. • Help Chimney Swifts rebuild their populations by building a nesting tower. Contact the Chimney Swift

Conservation Association at www. chimneyswifts.org for instructions. • Start tracking and recording Chimney

Swifts in your area and report your findings to eBird and your local birding groups.

Catherine Greenleaf is the director of St. Francis Wild Bird Center in Lyme, N.H. If you find an injured bird or turtle, please call (603) 795-4850.