Photo: Carolina Chickadee, Gary Robinette/Audubon Photography Awards
The Wildlife Sanctuary program helps homeowners create habitat in their own yards, with the aim of attracting and supporting beneficial wildlife that breed and live in our area. There are 42 Sanctuary Species, and you can learn more about them here. A yard that attracts 10 Sanctuary Species that nest, breed, forage, shelter, or hunt in the yard can be certified as a Wildlife Sanctuary our motto is, “Let the animals decide.”
Carolina Chickadee, Maxine Okazaki/Audubon Photography Awards
One Sanctuary Species is the Carolina Chickadee (Poecile carolinensis), that common, cheery visitor to backyard bird feeders. Chickadees are winter residents, and this small bird must contend with cold and consequent heat loss. About half survive the winter. Homeowners can help them survive by planting an evergreen shrub or tree to provide shelter from cold winds, and by providing a bird feeder. Hang feeders a short distance (maybe 6 to 10 feet) from tree and shrub cover, so birds can quickly seek cover when they spot predators, like hawks or stray cats. Chickadees are sentinels and warn other wildlife of approaching predators with their Chick-a-dee-dee-dee alarm call. They are cavity-nesters, so preserve trees with cavities, dead or alive, to provide roosting and nesting sites. Chickadees will use nest boxes, too.
More than anything, though, Chickadees need a yard full of native plants. How can that be? Chickadees eat seeds, so why do they need native plants?
Native plants are required to support the insects on which Chickadees depend for over half their diet. Caterpillars and other insects are especially critical when Chickadees are raising young in spring. Because nestlings need protein to grow, they must eat insects. Most native insects are specialists: they eat only the host plants with which they co-evolved. Without the native plants, there are fewer native insects, and without the insects, the birds cannot thrive, no matter how many bird feeders are available to them.
Carolina Chickadee, Minnie Lucas/Audubon Photography Awards
An ingenious study conducted by Douglas Tallamy and his colleagues in yards right here in the DC area confirms the effect. The scientists measured the amount of native plant material in each yard, and they observed whether Chickadees nested in it, and how successful their nesting efforts were.
Yards in which less than 70% of the plant material (trees, shrubs) was native were “food deserts” that could not support enough insects to sustain chickadee families. Chickadees were less likely to nest in such yards, and those that did, had less reproductive success. The result was declines in Chickadee populations.
So, as you watch the Chickadees visit the bird feeder through your window in this cold winter weather, think ahead to spring and plan to fill your yard with native trees and shrubs to support next year’s Chickadee families.
Catch up on past Wildlife Sanctuary Almanac articles here.