Photo by FBS Member

Glenda Simmons

One Nestbox Bluebirds Like

See attached plans for one nestbox, which has received the "stamp of approval" from bluebirds in Clay County, FL. Other bluebird enthusiasts endorse the Gilwood nestbox.  This has proven to be a good choice in areas where house sparrows are a problem.  You can also click Here to see a 3D view of the finished product.  Use your mouse to rotate the house to see all the sides including the top and bottom.  The 3-D view of the bluebird nest box was created by Kyle Lamirande, Boy Scout Troop 279, Jacksonville FL, as part of an Eagle Scout project.

Note that the opening in the door of the Florida bluebird box is precisely 1.5" inches in diameter. This is critical in order to keep Starlings from taking over the nestbox. An oval hole precisely 1 ?" x 2¼" can also be used, but it is easier to drill a round hole with a 1½" bit and also easier when placing a metal shield around the opening to discourage woodpeckers or squirrels from enlarging the opening.

A good floor size is 5"x 5". Some plans on the Internet call for a 4" x 4" floor, but some people who maintain bluebird trails report better success with the 5" x 5" floor size. Of course, this is anecdotal, and lacks any scientific validity. Bluebirds may need as much ventilation as possible in Florida’s warmer climate.

The ¼ " vent holes on the sides of the nestbox should be drilled at an upward angle to prevent water from running inside the nestbox.

The 9"x11" roof is good in Florida in order to provide more shade for the nextbox, to help prevent rain from blowing into the nestbox and to help prevent any animal that manages to overcome the predator guard from sitting on the roof and reaching into the nestbox to attack the contents.

The attached Florida plans also include directions for mounting the nestbox on a free-standing pole and for a predator guard to help protect bluebirds from possible predators, such as snakes, raccoons, cats and squirrels.

As a further protection against possible predators, nestboxes should never be mounted on trees, utility poles, or fence posts. These mounts provide ready access for climbing or slithering nestbox raiders.

The bottom of the nestbox entrance opening is no lower than 5’ above the ground. While bluebirds will nest in boxes lower or higher than that, this is a good height for being able to look into the nestbox during the weekly check.
 
No predator guard is 100 percent foolproof, and the one in the attached plans is no exceptions. On several occasions snakes have managed to climb up the outside of the stove pipe predator guard and devour the hatchlings in the nestbox.
 
To help deter predators from reaching the nest box, the Florida Bluebird Society is experimenting with various other options.  This includes coating the pole with axle grease and placing a sticky substance under the stove pipe predator guard.

Of course, a predator guard won’t stop airborne predators, such as the red-shouldered hawk, which is a familiar sight in Florida.

on their prey. This includes areas such as golf courses, mowed meadows, cemeteries, open roadsides, and open woodlands or orchards.

 

Nestboxes should not be placed close to brushy areas, where they might attract predatory House Wrens, or close to trees or shrubs, where squirrels or cats could jump on them.
 
Nestboxes should be placed at least 100 yards apart.  The North American Bluebird Society recommends nestboxes be placed 125 yards apart.

 

The entrance hole should face away from the prevailing winds, and ideally towards a tree or shrub no more than 100 feet away so fledglings can fly to them when leaving the nestbox. It is important that fledglings have a place to fly to where they can be safe from ground predators, such as free-roaming cats.

Then the cycle may begin all over again, with the parents raising as many as three broods of birds in one season.
And if the parents really like your nestbox, they could come again the following year. It has been estimated that approximately one-third of the bluebirds return to the same nesting site the following season.

 

 

Putting up a bluebird box is only the beginning. In order to have a successful, bluebird-friendly trail, nestboxes must be monitored regularly. It has been said that it’s better not to put up a nestbox at all than to put up a nestbox and not monitor it.

 

Why monitor a nestbox? For the sake safety of the bluebirds and for your own satisfaction.

 

Nestboxes should be checked and cleaned out prior to the start of the each nesting season. This is the time to remove any mice or wasp nests that would prevent bluebirds from using the nestbox.

 

Nestboxes should be monitored at least weekly to determine the status of the birds and to insure that non-protected species, such as the House Sparrow, have not killed the bluebirds or driven them away. If House Sparrows have taken over the nestboxes, they should be destroyed before they can reproduce and cause further harm to bluebirds.

 

As a precaution, even during the season when checking nestboxes, rap hard a couple of times on the side of the box, then stand to the side when opening the door, in order to give any "unwanted guests" the opportunity to get out. Remember, not only birds may sometimes take up residence in a nestbox. You could also find anything from snakes to mice and or even a lone bat.

 

Of course, other birds like Tufted Titmouse or Carolina Chickadees, might decide to nest in the box, also. These are protected, native species and cannot be disturbed. You were probably hoping for bluebirds, but the nestbox is being used, and that’s what really matters.

 

Bluebird hatchlings also should be checked for parasites, such as blowflies. If numerous blowfly larvae are in the nestbox and attach themselves to the hatchlings, they can weaken and eventually kill the young birds. If blowfly larvae are found in the box, the nest can be replaced with clean pine needles shaped like the original nest. If blowfly larvae have attached themselves to the nestlings they should be pulled off immediately.

 

Weekly monitoring also provides an opportunity to determine the condition of the nestboxes. Have squirrels or Red-Bellied Woodpeckers enlarged the entrance hole so starlings can get into the box? If so, replace the door immediately, or put up a metal hole guard. Has weathering caused any of the joints to separate, allowing rain to enter the box? If the box is not occupied, repair or replace it immediately; if the nestbox is occupied place duct tape over the lose joint(s) as an emergency measure, then replace or repair the box after the young babies have fledged.

 

In Florida, Eastern Bluebirds can fledge through August. After bluebirds have finished nesting it is time to prepare for the coming season. This is a good time to inspect your nestboxes and make any necessary repairs.

So, you’ve made an inviting box and put it in the right location. What next? All you can do now is wait and see, like any "expectant parent." Don’t be discouraged if bluebirds don’t nest in your boxes the first year you put them out. Give bluebirds time to find them. Some boxes have been installed for several years before bluebirds chose them. If your nestbox is in the right habitat and receives the bluebirds’ stamp of approval, don’t give up hope. If they find your boxes and like them, they will take up residence. In the meantime, other delightful and needy native cavity nesting birds such as the Tufted Titmouse, Carolina Chickadee or Great-crested Flycatcher might use your nestbox to raise a family.

 

last egg is laid so that all the babies will hatch at about the same time. It takes about two weeks for the eggs to hatch.

 

The incubating period and first five days is a critical period in the lives of the hatchlings. Only the female bluebird has a brood patch and can incubate the eggs or keep the hatchlings warm during the first week of their lives. Should anything happen to the female during this period, the hatchlings probably will die. Should anything happen to the female after this period, the male bluebird may be able to successfully rear the nestlings if there is sufficient food available nearby.

 

Young bluebirds "fledge" from (leave) the nestbox when they are between 16 and 21 days old. The young birds still can’t fly very well and depend on their parents to feed them for several weeks.  Finally, when they are about a month old, the young bluebirds have earned their wings and are ready to take off on their own.