This Unassuming Structure is Giving a Special Group of Birds a Home

Looking at this structure, installed recently in Herndon's Runnymede Park, one might never guess what it is.

It is a chimney swift tower - and, thanks to the Friends of Runnymede Park, it is helping to increase the numbers of a very special bird in Herndon by giving them a place to roost.


The chimney swift is a bird that feeds on insects like mosquitoes, gnats and midges - therefore many consider it a desirable bird to have around.

However, the chimney swift population has dropped by more than 50 percent nationwide since the mid-90s.

Carol Hadlock, a member of the Friends of Runnymede and an avid bird-watcher, says that is because their homes are rapidly disappearing.

Hundreds of years ago, before European settlers arrived in America, chimney swifts most often roosted in hollow trees. However, as lands were rapidly developed, more and more hollow trees were cut down to build homes.

So, the chimney swift adapted, and began roosting in chimneys (hence their name). The biology of the chimney swift requires that it roost on a flat, vertical surface.

However, as home designs modernized, more and more people began capping their chimneys, or constructing them with metal flus or slippery terra cotta that make it hard for the birds to perch.

"People began capping their chimneys to keep rain and weather out - and, because when birds would build their nests in them, the babies can be very loud," Hadlock explained. 

Therefore, the modern-day chimney swift has a tougher time finding a place to rest at night or build its nest, and thus numbers have been dropping.

So, the Friends of Runnymede Park decided to band together and give local chimney swifts a place to call their own.

"To increase the population of these federally-protected birds, who do so much to rid our skies of annoying insects, we must provide more roosting opportunities," the Friends say on a sign near the tower that informs people of its purpose and about the chimney swifts it houses.

The tower has steel legs anchored in cement, and the body of the tower is made of wood with grooves every four inches that allow the birds to perch. For added comfort, the tower has rigid insulation inside.

A metal band at the top keeps other predators such as snakes out - being slippery and hot in the sun - and holes at the bottom provide ventilation.

Hadlock said, if one factors in the cost of supplies and the labor needed to build a tower such as this one, then the tower is worth $3,600. But, volunteers such as Dave Schumaker and Dave Swan - two local residents who were the main builders of the tower - donated much of their time, bringing the cost down significantly.

Hadlock said, local chimney swifts are currently on their way to South America, where they migrate each year, but they'll be back in the spring.

"In April, when they come back, we're hopeful that a nesting pair will find our chimney," she said.

Chimney swifts like their space, and one pair won't nest too close to another - so, only one pair will build its nest in the tower, but many will still rest in the tower each night, Hadlock explained.

In fact, it's often quite a show when chimney swifts call it a night - they will circle the tower at a rapid speed, and then suddenly drop into the tower to roost.

The chimney swift tower is located near the entrance to Runnymede Park, by the parking lot. It is the first free-standing tower in Herndon.

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