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The Eastern Bluebird |
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A Brief History The Eastern Bluebird in Florida Welcome to the wonderful and delightful world of the Eastern Bluebirds in Florida. The Eastern Bluebird, whose official Latin name is Sialia sialis, is a member of the Thrush family. There are three species of bluebirds: Eastern, Mountain and Western. The Eastern Bluebird is found throughout the United States east of the Rocky Mountains and in the southern part of Canada and down into Mexico. That includes all of Florida. Bluebirds have been reported from Escambia to Nassau counties across the northern part of the state, and as far south as Key West in Monroe County. (ebird.org/view and explore data/maps/select species – Eastern Bluebird/continue/change location/Florida/entire region/continue). It is highly unlikely to see the other two members of the bluebird family in Florida.
Some
Eastern Bluebirds stay in an area year round. Others, like Human Snowbirds,
move south during colder weather. One study reported that in October and
November, some Eastern Bluebirds from further north moved into northwest
Florida. This study was confirmed by the increase in bluebirds seen during
the winter months at a retirement community in Clay County, FL. A Beautiful Little Bird
The
female Eastern Bluebird is not as brilliant as the male, but just as
beautiful, nevertheless. The top of her head, back and tail are battleship
blue. Her chin, throat and flanks are a pale orange. Like the male, she has a
white belly and undertail coverts. Add
a beautiful song to eye-catching colors, and you have a bird which has become
a favorite among poets and songwriters from Henry David Thoreau to Paul
McCartney when they want to describe love, joy, happiness and beauty. In The Beginning… America’s
love affair with the bluebirds stretches back to Colonial days when
immigrants began clearing the forests to create homesteads and farmlands. As
the Colonists cleared the land they unwittingly became one of the bluebirds’
best friends. Eastern Bluebirds thrive in open, grassy areas which have been
cut or mowed, are clear of underbrush and have widely scattered trees or high
bushes to use as a perch. (In modern times, bluebirds frequently perch on
telephone wires or fences.) Depending on the time of year, 68 percent of the
bluebirds’ annual diet consists of insects. They are often seen swooping down
from their perch to catch a grasshopper, beetle or other bug on or near the
ground.
During this time, the Eastern Bluebird population increased. It has been reported that in the eastern part of this country during the early 1800’s bluebirds were probably as common as the American Robin. Good Intentions, Bad Results Unfortunately the good times eventually came to an end. In the mid to late
1800’s, the Eastern Bluebird received a In
1850-1851, (English) House Sparrows were brought into the United States from
England and released in Brooklyn, NY. Those were the first of many House
Sparrows introduced into the United States in subsequent decades. Ironically,
one of the reasons the House Sparrow was brought into the United States was to
help control an insect infestation damaging trees in New York’s Central Park.
Unfortunately, unlike the insectivorous Bluebird, 96 percent of an adult
House Sparrow’s diet consists of grain and weed seeds. The
House Sparrow population exploded, and quickly began having an injurious
impact on native cavity nesting birds such as bluebirds. Nesting sites once
available for bluebirds were invaded by House Sparrows. But the House Sparrow
doesn’t just evict the bluebird from the nest site; House Sparrows will destroy
the eggs or kill any adult and nestling bluebirds they can trap in a nest
site.
Starlings,
like House Sparrows, are aggressive birds which will take over nesting sites
from the Eastern Bluebird. Starlings and House Sparrows now are counted among
the most numerous songbirds in America. Because of their sheer numbers they
can have a negative impact on native competitors such as bluebirds.
Fortunately Starlings are larger than bluebirds, and cannot get into a
properly designed bluebird nestbox. The Eastern Bluebird also has been at the mercy of the weather. Severe storms and hurricanes – particularly during the breeding season – can have a severe but short-term but severe impact on the bluebird population. A Troubled History The
history of the Eastern Bluebird has been a series of good times, bad times.
The 1900’s were no different. In the beginning of that century, the House
Sparrow population apparently peaked, as the country began moving out of the
horse-and-buggy days into the era of gasoline-powered automobiles and farm
machinery. This meant less food for House Sparrows, which thrived on loose
grain found around farms and in animal droppings. But the good news was accompanied by bad news. The Eastern Bluebird population also was peaking about this time. Although bluebirds still were a common sight in some areas during the first decade or so of the 1900’s, the seeds for a precipitous decline already were being sown. As the years rolled by, farms in many areas were abandoned and reverted back to forests. In other areas, entire forests disappeared as loggers clear-cut every tree in sight.
The decision to use poison to control the fire ants is made despite the knowledge that increased use of pesticides, particularly DDT, made life even more hazardous for bluebirds in the latter half of the 1990’s. Pesticides were used to kill insects, which were the main item on the bluebird’s menu. The result was indirect poisoning of the bluebirds. As a result of all these problems the population of Eastern Bluebirds was estimated to have dropped 90 percent between the 1920’s and the 1970’s. The News Wasn’t All Bad Some concerned individuals recognized that the bluebird was in trouble. Nestboxes have had been used since Colonial days to attract bluebirds. But it wasn’t until the 1920’s that Thomas Musselman, of Quincy, IL, started spreading the idea of starting a bluebird trail that extended beyond local boundaries. This concept caught fire and has proven to be a major factor in the survival of the bluebirds. The
continued placement of bluebird nestboxes becomes even more important in
states such as Florida, where an ever-increasing population results in an
ever-increasing loss of suitable habitat. Giving Them What They Want
That being said, what do the bluebirds want? Basically there are only two main things to keep in mind when putting up a bluebird box: (1) A good nestbox (2) in the right location. It has been said that there are as many different nestbox styles as people
who maintain bluebird trails. Though that is an exaggeration, it underscores
the fact that there is no one "perfect" nestbox, only nestboxes
that bluebirds are attracted to and use. That being said, all there are
certain fundamental requirements that all nestboxes should meet. One Nestbox Bluebird 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.
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.
The
nestbox in the Florida plans is bolted to a 40"
length of 1¼" ID PVC, which is then slid over the 1" ID conduit.
The nestbox is fastened to the PVC rather than the metal conduit because the
nuts and bolts eventually rust and it is easier to remove them from the PVC
than it is to remove them from the metal conduit. Approximately
25 inches of the 6’ metal conduit is placed inside the PVC in order to
prevent the weight of the box from bending the PVC. The conduit is sunk
approximately 17-18 inches into the ground. The
bottom of the 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. Lining
up the holes in the nestbox, PVC and conduit for the ¼" bolt can be a
challenge. The trick is to make sure the holes are drilled straight. If the
holes are drilled at an angle, it is extremely difficult to insert the bolt
through the openings.
A predator guard won’t stop airborne predators, such as the red-shouldered hawk, which is a familiar sight in Florida. After You’ve Made the Nestbox, Where do
You Put it? In Florida, bluebird nestboxes should be in place by the end of January. This gives bluebirds time to inspect the nestbox before they start nesting the end of February or the beginning of March. As noted before, ideal habitat for Eastern Bluebirds is an open area with short grass that has been cut or mowed and, with little or no underbrush. There should be a perch nearby, such as a tree limb or telephone line that allows the birds to look for insects and then swoop down on their prey. This includes areas such as golf courses, mowed meadows, cemeteries, open roadsides, and op en 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 125 yards apart, according to the North American Bluebird Society. 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. OK, You’ve Put Up A Nestbox, What Now?
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. Then
the cycle may begin all over again, with the parents raising as many as three
broods of birds in one season.
If Bluebirds Do Their Part, You Must Do
Your Part 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 are 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. Where to Learn More Hopefully this brief review of the history of the Eastern Bluebird and the importance of putting out nestboxes to help preserve a bright future for these beautiful native songsters will inspire you to create your own "Bluebird Trail." Remember, every bluebird trail "Bluebird Trail" starts with the first box. For those people who would like more information on a wide range of subjects related to the Eastern Bluebirds, there are many excellent websites on the Internet. They include:
The Florida Bluebird Society wishes to thank these sites for the information which was contained in this article. The Florida Bluebird Society also thanks Wendell Long Photos for permission to use the photographs in this article. You also can also contact the Florida Bluebird Society at floridabluebirdsociety@yahoo.com or at floridabluebirdsociety.com |
Settlers soon
realized that bluebirds are secondary cavity nesters. That means their beak –
unlike that of some birds such as the woodpecker – isn’t strong enough to
chisel out its own nest cavity in a tree. Instead, bluebirds rely on cavities
created by nature, other critters or humans. Putting two and two together,
settlers soon began putting out nest boxes to attract bluebirds in order to
help combat the insects feasting on the crops in their fields and gardens. In
the days before pesticides, farmers appreciated the bluebird’s help
controlling insects.
one-two avian
punch that sent the populations into a tailspin.
The accidental
importation of the fire ant in the 1930’s compounded the bluebirds’ problems
in the South. Fire ants still represent a major problem on bluebird trails in
the Southern states. When fire ants get into a nest, they can reduce a baby
bluebird to a skeleton in a few days. It is not a pretty sight to find
nestlings in a bluebird nestbox one week, and then come back the following
week and find nothing but bones. When a fire ant mound is found near a
nestbox pole, it could be only a matter of time before the nestbox is invaded
and the nestlings eaten alive. One solution is to spread ant poison around
the mound. Where this has been done, the nestlings have survived and there
has been no visible evidence that the ant poison has had an adverse affect on
the birds.
No predator guard
is 100 percent foolproof, and the one in the attached 
