By allowing ads to appear on this site, you support the local businesses who, in turn, support great local journalism.
Extension: Forsyth County Master Naturalists keep an eye on Eastern Bluebirds
Nancy Mitchell
Forsyth County Extension Master Naturalist Volunteer Nancy Mitchell uses a mirror to check for eggs in a bluebird nest. - photo by Heather Kolich

This past Monday I joined Forsyth County Extension Master Naturalist Volunteer Nancy Mitchell at Chattahoochee Pointe Park for her weekly monitoring activities along the Bluebird Trails. It turned out to be more of an adventure than I anticipated.

Bluebird Trails

It’s hard to believe it’s been over 10 years since Fowler Park opened, but it was this construction that inspired the 2010 class of Forsyth County Extension Master Naturalists to develop their first citizen science project, the Bluebird Trail. 

The goal of this project was encouraging eastern bluebirds to return to the area they had fled during the land disturbance associated with creating the park.

Working with the Parks and Recreation Department, Master Naturalists built and installed 14 bluebird nesting boxes at Fowler Park. 

The following spring, all 14 boxes hosted nesting bluebird pairs and successful fledges from each box. Nesting pairs returned each year, and the success at Fowler Park has been replicated with a second Bluebird Trail at Chattahoochee Pointe Park.

Nesting and raising hatchlings are significant undertakings. The female bluebird spends 2-5 days gathering pine needles, grass, and straw and weaving them together to form a nest. 

Then she lines the nest with soft materials, like feathers and hair. When the nest is ready, she’ll lay one egg each day until the clutch numbers 3-7 eggs.

Incubation requires 13-20 days, during which the female remains on the nest, keeping the eggs warm and waiting for the male to bring her food. 

Good nutrition and warm temperatures shorten incubation time. Fortunately, the eggs all hatch on the same day, reducing the size difference between babies so that the first to hatch doesn’t outcompete later hatching babies for food. But with no feathers, the babies still depend on their mother’s body heat to keep them warm.

Both parents work to feed the hatchlings a high-protein diet consisting mostly of insects, delivered to their gaping mouths about every 20 minutes. 

Finding the abundance and variety of insects they need for the babies is easier in a foraging environment that is rich with plant diversity, especially native plants, including trees, shrubs, herbaceous plants, and grasses. 

After feeding them for 17-20 days, the parents coax the young out of the nest to take their first flight.


Nest box monitoring

A team of Master Naturalists monitor the Bluebird Trail boxes during the mating season and maintain them during the off season. 

A first brood has already fledged from many of the boxes this spring, but Nancy explained that if the parents have been successful with the first nesting, they may return to the nesting box and try for a second brood.

Since the team has found that a clean nesting box encourages a second nesting, cleaning out old nests was one of the tasks for the day. Our removals included an empty bluebird nest and two unoccupied nests made of materials that indicated other species.

 The nest made of sticks on top of a bluebird nest probably belonged to a mouse. We also removed two wasp nests from unoccupied boxes and relocated a box that had never been occupied to what we hope will be a more attractive location.

Attracting Bluebirds

Bluebirds are cavity nesters, but they can’t excavate a cavity in a tree like a woodpecker does, so they must find a ready-made house. Select a bluebird box with a hinged side that opens to allow cleaning and mount it on a sturdy post at least 3 feet above the ground. 

Locate the box where the bluebirds have a good view of a meadow or grassy area in front and some trees or shrubs behind where they can land and reconnoiter. 

Insects comprise two-thirds of adult bluebirds’ diets, so avoid use of pesticides to ensure abundant food sources. Berries and fruit from native plants comprises the balance of their diet. 

Caterpillars are especially important first foods for hatchlings. This diet generally meets the birds’ water needs, as well.

For more information and instructions for building bluebird nesting boxes, see the Natural Resources Conservation Service publication “Eastern Bluebirds” at bit.ly/3MXTsxg.

UGA Extension strives to translate the science of life for use in everyday living. Forsyth County Extension is supported by the University of Georgia, Forsyth County Board of Commissioners, Forsyth County Board of Education, and United Way of Forsyth County.

Bluebird
Bluebirds weave nests from pine needles, grasses, and straw. This bluebird female has already constructed a new nest on top of the nest from the first hatching this spring. - photo by Heather Kolich