America is blessed with a large number of different swallow species
and some form of them can be found just about everywhere.. Of
these, the Purple Martin is the largest member. Within the martin
family of North America, there are three distinctly different
subspecies, each having their own unique nesting habits. In
the Pacific Northwest can be found the Progne subis
arboricola. These birds once used the natural cavities
in trees in which to nest in the wild, but are now beginning to use
individual nesting boxes placed on poles by man. The
transition is slow, but little by little, this species is beginning
to seek these boxes out at nesting time. In the Desert
Southwest, Progne subis hesperia still uses
natural nesting sites such as holes in cacti. They have yet to
make the transition over to man made nesting boxes. And
finally for us here in the Eastern half of the U. S., there's
our very own, Progne subis subis. This species
encompasses the entire eastern U.S. ranging from the Florida Keys
all the way northward into parts of Canada. This species has
almost totally developed a dependence on man to supply them housing
in which to nest. In general, it will be this species that
this page is devoted to.
male Purple Martin is a beautiful bird, easily recognizable, fully
cloaked in black feathers. His back, neck and chest feathers have a
steel blue iridescence which can look purple when sitting in the
proper light. The tail and wing feathers are duller in
coloring and do not have this iridescence. Only the mature
males have all black feathers over their entire bodies.
Immature males do not attain the full black body dress until they
are in their second breeding year. The females do not have
entire bodies of black and never attain this solid black look.
Instead, they are much duller than the males and always have a
grayish mottled belly. See the photo series below for a
clearer understanding of the plumage of these birds.
|photo courtesy D.
||photo courtesy J. Hill III,
||photo courtesy J. Hill III,
||photo courtesy J. Hill III,
Purple Martins are the largest member of the swallow
family with mature birds measuring up to 8 inches long. Most of this
length is due to their extremely well developed wings, the tips of
which often reach beyond the ends of their tails. They are master
fliers which probably accounts for their superb wing development.
They have a short, flat, triangular shaped bill which is ideal for
catching insects while on the wing.
As with most birds in
nature, the males are the ones with the brighter colors. Adult
males, are a very dark steel blue to almost black. The reflection of
the sun off their dark plumage gives off a purplish hue, thus the
name "purple" martin. Males do not achieve their full dark
coloration until after their second year.
The females also
have dark backs but don't have the black bellies like the mature
males. Their undersides are of a mottled gray appearance. Fledglings
and first year males have a similar appearance as the
are gregarious in nature and prefer to nest in 'condo' units.
These supplied houses usually have more than 6 individual cavities
to start with and often have as many as 20 or even 30 cavities in
each house. Although it's sometimes difficult to get a colony
started, once established, the colony will grow year after year as
long as there are nests available to them. Colonies of 300 nesting
pairs are not unheard of, although the norm is more like 6 to 10
nesting pairs in the average established site.
|photo courtesy Doren Clare,
Martins usually build a haphazard nest using sticks,
twigs, bits of straw, pine needles, leaves or whatever's
available. In the back of the nest they form a bowl and lay
from 3 to 7 soft white eggs with the norm being 4 or 6.
Immature birds usually lay from 2 to 5 eggs while the more mature
birds usually lay from 4 to 7.
One thing of note, in the smaller cavities, martins often
use mud to make a dam just inside the entrance hole. It is not
readily known why they build these mud dams, but it's thought they
might be for protection, either from enemies or to keep the elements
out. These mud dams are usually not present in larger cavities
where there is ample room.
|photo courtesy Doren Clare,
lasts from 15 to 17 days, with the female doing most if not all the
work. The young are born without feathers and take about 28 days to
fledge, or leave the nest. The young may return to the nest for a
few nights, after which they will start spending their time with the
adults. The adults will continue to feed the young until they have
acquired enough skill to catch their own food.
are cavity nesting birds. In the wild they search out nesting sites
in holes of trees, cliffs and man made structures. Over the years
man has learned to provides nesting sites for them and the martins
use these houses to raise their young. Likewise, martins have
learned through what is called 'generational imprinting', to seek
out these man made structures. In the Eastern U.S., martins almost
exclusively use man made housing. Martins have a very strong "site
tenacity" and if are successful in raising a brood, will often
return to the same site to nest year after year.
their nests usually consist of mud, sticks, grass and straw, topped
off with green leaves as a trimming. These green leaves are added
periodically, although the reason why is not fully understood. It is
thought that these leaves are used to keep the eggs moist during
|photo courtesy Mike Cantrell,
most part, insects make up the majority of the martins diet. They
often can be seen on early morning and late afternoon thermals,
dipping and diving, snatching insects out of the air. Insects on the
menu are ants, beetles, butterflies, damselflies, dragonflies,
mayflies, moths, stinkbugs, wasps, a few houseflies and maybe one or
two mosquitoes. Out of all of these, their favorite food is probably
the dragonfly. During year end nest cleaning, the compartments are
littered with dragonfly wings and skeleton parts.
about martins is that they consume thousands of mosquitoes each day.
Not true according to studies done on the diets of martins.
Mosquitoes make up less than 3% of the martins diet. If you stop and
use a little common sense, this can be figured out on your own.
Martins feed high in the air, sometimes as high as 300 or 400 feet,
while at the same time, mosquitoes usually stay within 15 to 20 feet
of the ground where it's moist, therefore, the two seldom cross
paths. Now, if a mosquito happens to be in the path of a
martin, the martin will take it, but I doubt the martin will go
looking exclusively for them. And besides, the amount of energy
spent in gathering mosquitoes would far out way the nutritional
benefits and also, if you stop to think about it, mosquitoes become
most active at dusk, about the same time martins and other birds go
as all the rest of the swallow family, drink and bathe on the wing,
therefore a good fresh water supply is required somewhat
nearby. This water source could be within 2 miles of the
site. This means either a lake or pond of some sort or an open
stream or river. Although it has been noted that martins will
use a large swimming pool for a quick dip or drink, they will not
use a source such as a bird bath. Martins will not land to
drink or bathe,
For a more
detailed description of the daily habits of purple martins, go to
the Habits Page
Since martins eat only insects, they have to migrate
to continually have a supply of food. Their range is throughout most
of the Eastern U.S. and Canada with some migration up the west coast
of the U.S. Around the end of July, after the young have fledged and
are capable of taking care of themselves, they can be seen
congregating into large flocks of thousands of birds, preparing
themselves for the long migration south. Each year wave after wave
of martins make the trek from North America south to Brazil and
surrounding areas in South America. They make the trip either via
Central America or down the Florida peninsula, through the Florida
Keys and Bahamas and across the Gulf of Mexico to South America.
Martins are good fliers, and under normal circumstances the trip is
not too hazardous, but a large storm in the Gulf of Mexico at the
wrong time can devastate a migrating flock.
Martins are a
protected species under the Federal Migratory Bird-Treaty Act, thus
it is illegal to harm the birds, their nests or any other part of
their habitat. It is also illegal to trap or possess these birds
without proper permits from the U.S. Fish and Wildlife
In the following map, the shaded area indicates the
overall range of the Purple Martin, and the cross lines indicate the
approximate arrival of the scouts in a given area. These dates
are only approximate and may vary by as much as a couple of weeks
|artwork courtesy J. Hill III,
There is no real benefit to erecting and maintaining a
purple martin site other than the shear enjoyment of it. They are a
delightful bird to have around, and are actually friendly towards
man, allowing the inspection of their nests without any apparent
negative effects to the birds. When the nests are put back up in
place after inspection, the parent birds soon return to their daily
activities as if nothing ever happened. Sitting back and watching
their antics throughout the day is a pleasant and relaxing past
time. In fact, in time, you'll catch yourself spending more and more
time watching and enjoying them.
Back to Chuck's Purple Martin
This page created and
by Chuck Abare
The Registry of Nature Habitats
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