There are over 20 resident Florida birds that nest in cavities in trees or branches. These include Eastern Bluebird, Carolina Chickadee, Tufted Titmouse, White-breasted Nuthatch, Great-crested Flycatcher, Carolina Wren, and woodpeckers among others. Woodpeckers are considered primary cavity nesters because they excavate their own cavities, while the others are secondary cavity nesters who rely on naturally occurring holes or ones chiseled by woodpeckers.
Snags, or standing dead trees, are crucial for woodpeckers as they serve as nesting sites, provide a food source through insect-rich wood, offer roosting spots, and contribute to overall ecosystem health by supporting biodiversity. Photo by SunnyS, Adobe Stock.
Most woodpeckers need snags (dead trees) and dead limbs for excavation, and these are often in short supply in neighborhoods. We can make up for this scarcity by installing and maintaining nest boxes for bluebirds and other cavity nesters.
If you must have a tree cut down, ask the arborist to cut the trunk at approximately 12 feet. The snag will slowly decay and, in the meantime, feed and house woodpeckers and other cavity nesters.
Create Habitat
Nest boxes are important but to produce healthy populations of birds, creating habitat in our yards is of utmost importance. What you plant in your yard and how you maintain it does matter! Diversify your yard by planting native trees, shrubs, grasses, and wildflowers which provide sustenance and habitat for native insects that will then be eaten by birds and fed to their young. Connect the trees and shrubs together in beds, allowing the leaves to carpet the ground. Leaf litter is important habitat that supports the food web in your yard. Also, avoid pesticide use.
You do not need to provide bird food for bluebirds as they are excellent hunters of insects, which are highly nutritious. However, if you want to provide them with an occasional treat, they do love mealworms. Because purchased mealworms do not provide complete nutrition (they are lacking in calcium), they should be used as a supplemental food source, offered on a limited basis – a treat for the birds.
Adult bluebirds also eat fruit, so encourage pokeweed, beautyberry, and elderberry to grow in your beds. Plant fruiting species such as black cherry and holly trees. At the feeder, bluebirds will also enjoy sunflower chips and suet cakes as occasional treats. Nestlings, however, are always fed insects.
Bluebirds prefer an open habitat, so the author installed this nest box in her pollinator garden of wildflowers and native grasses. Photo by Donna Legare.
Nest Boxes
When buying or building a nest box, make sure it is designed properly with the correctly sized entrance hole. For instance, bluebird houses should have a hole that is 1 ½ inches in diameter. The same house can serve well for birds that require a slightly smaller hole. I have had titmice, chickadees, and nuthatches use our bluebird house. Interestingly, bluebird nests are almost always constructed of pine needles or grasses or a combination of the two. Chickadees use a lot of green moss in their nest and then line it with soft cottony material. It is just as much fun to watch birds collecting nesting materials as it is to watch the constant visits by parents bearing insects, and I always feel lucky if I am at home when the fledglings leave the box.
A good bird house has ventilation holes or space under the roof overhang, has drainage holes, has the roof extending over the walls for maximum protection from rain and sun, does not have a perch that a predator could use for support and is protected by a snake/raccoon predator guard. These are commercially available, or you can make your own using six-inch PVC piping or stove pipe below the house.
Nest boxes should be cleaned after each use. Remove the old nest. I carry a bucket with soapy water and a rag so that I can wipe the inside thoroughly and then rinse well with clean water. Most nests are clean because parents remove fecal sacs. Watch as they fly in with an insect and leave with a white sac. This keeps the nest clean, so it is less likely to attract predators and decreases the chance for disease. Fledglings often defecate while leaving the nest so there is usually a need for cleaning.
Old Nests May Become Bumblebee Habitat
Place old nests on the ground tucked up under a tree or shrub. It may be used by an overwintering bumblebee. Once I forgot to clean a gourd which held a flycatcher nest. I laid it on the ground at the base of a parsley hawthorn tree. Next spring, I lifted it, heard a buzzing sound, and immediately placed it back on the ground. A bumblebee flew out. She had overwintered in the old nest. Isn’t nature fascinating!
A Great-crested Flycatcher feeding a nestling. Photo by Danita Delimont, Adobe Stock.
Great-crested Flycatchers
These flycatchers migrate to our area in springtime and are quite common; listen for their distinctive “zweep, zweep” call. As their name would indicate, they are insect eaters. They are also cavity nesters and will accept a gourd or wooden house. They usually place a snakeskin in the nest if they can find one. If not, they will include a piece of clear plastic litter. I have seen flycatchers nest in abandoned newspaper boxes and even in a clothespin bag hanging on a clothesline.
Joyful Observations
There is no doubt that watching bluebirds and chickadees nesting in our yards brings us joy. I have been installing nest boxes and teaching about cavity nesting birds for 50 years, beginning as a volunteer with Alachua Audubon Society while in forestry/wildlife school in Gainesville. This summer we observed something we have never seen before, though we have included this behavior in our classes.
Bluebirds nested successfully in our front yard nest box early in the season and then a second time in June. When we returned from a late July vacation, we noticed that bluebirds were once again using the box and this time there were four birds tending the young – a mature male, a mature female, and two juveniles. One time a juvenile carried a pokeweed berry to the nestlings, which the parents would never do. Later a juvenile was clinging to the entrance hole with nothing in its beak. The mature male flew up with an insect in his beak, passed it to the juvenile who then, rather than eating it, fed it to one of the nestlings. These youngsters are learning parenting skills. It was a privilege to watch.
For more information on nest box dimensions and creating habitat in your yard, pick up the free booklet Planting a Refuge for Wildlife by FWC (Florida Wildlife Commission) at their office or at Native Nurseries.