Attracting
& Managing Martins
Purple
Martin Houses
Purple
Martin Information
Purple
Martin Resouces
In the backyards
and hearts of bird lovers across North America, Purple
Martins occupy a unique and cherished place. East of the
Rocky Mountains, for more than a century, these handsome,
graceful swallows have nested almost exclusively in
human-made birdhouses. Their inextricable association
with people has spawned an active trade in
architecturally-diverse martin houses, as well as
comprehensive popular literature and scientific research
on the behavior and nesting requirements of the species.
Purple Martins breed across most of the eastern and
central United States, as well as southern Canada.
Whereas their distribution in eastern North America was
once probably relatively patchy, Purple Martins now occur
widely, settling opportunistically in towns and cities
where appropriate housing is available. Purple Martins
also breed in isolated pockets throughout the western
states and Mexico, using abandoned woodpecker holes in
dead trees in the manner of their ancestors.
The Purple Martin is the largest swallow in North
America, and one of the largest in the world. Like all
swallows, Purple Martins subsist entirely on insects
captured in flight. They forage solitarily or in pairs,
rarely assembling in large numbers around insect swarms.
Purple Martins take insects from a wide variety of
families, including beetles, flies, moths, bees,
dragonflies, and others. Contrary to the claims of some
birdhouse manufacturers, Purple Martins do not consume
prodigious numbers of mosquitoes.
Purple Martins are usually socially monogamous. In
seeking to attract mates, males advertise their claim on
a nest by flying in a broad arc, diving to the nest, and
singing with head protruding from the hole. The pair bond
becomes well defined after a female comes repeatedly to a
nest and the male begins to treat her as a mate, staying
close to her on trips away from the nest. Copulation,
rarely observed, is assumed to occur within nest
cavities. On rare occasion, a male may have two mates.
Artificial Purple Martin houses represent a variety of
forms and materials, mostly on poles or wires several
meters off the ground. Even before the time of European
settlement in the Americas, Native Americans provided
hollow gourds for the use of nesting Purple Martins.
Gourds, including ones made of plastic, are still widely
used, especially in the southeastern United States.
Martin houses may also be box-shaped, with compartments
for multiple nesting pairs. Most such houses have 6 to 24
rooms, but some have hundreds. Single-compartment houses
are also used with some success, especially in the
western United States.
Being a successful birdhouse "landlord" of
Purple Martins involves much more than just putting up a
house and waiting for the birds to come. Attracting
Purple Martins and facilitating their breeding success
are complex and demanding endeavors, requiring
appropriate materials, space, and ongoing monitoring and
maintenance. Keeping European Starlings and House
Sparrows out of martin houses is a particular challenge,
involving physical removal of nests or other active
measures. Native species such as Tree Swallows may also
seek to co-opt houses intended for the use of Purple
Martins.
Purple Martins line their nest cavities with twigs and
grass, and always place mud at the base of the entrance
hole. Females do most of the work gathering nest
material, with males watching nearby. Purple Martins
fiercely defend their nests against intruding
conspecifics, with pecks and blows from the wings. In
general, males defend territories from other males, and
females from other females, although females, if their
mates are absent, will attempt to fend off intruding
males.
Females generally lay three to six eggs. Within a colony,
egg-laying may be highly asynchronous, spanning several
weeks. Incubation, performed mostly by the female,
usually lasts 15 to 18 days. In most clutches, all eggs
hatch within two to three days of each other. Young birds
fledge after about 30 days, whereupon parents lead the
brood away from the colony site for a day or more. The
immediate family generally stays together for several
days, sometimes returning to the nest to sleep. But
parents show no ability to recognize their own young, and
during the period after fledging, broods often mix, with
parents raising adopted fledglings as if they were their
own.
Shortly after the young fledge, Purple Martins begin
gathering in large roosts. These roosts, which are
usually in groves of trees or on the undersides of
bridges, can comprise hundreds of thousands of
individuals. Numbers diminish as birds depart on their
southward migration, throughout August and September.
Purple Martins spend the North American winter months in
the lowlands of South America, from Colombia to
Argentina, and especially in eastern Bolivia and southern
Brazil. They feed over agricultural fields and savannah
during daylight, and assemble in large flocks at night
roosts in cities and towns.
Description: The Purple Martin is the
largest swallow in North America, measuring about 8
inches in length. Like other swallows, Purple Martins
have long, pointed wings, and fly with exceptional grace
and maneuverability.
The adult male may be distinguished easily from other
North American swallows by its solid glossy blue-black
color. Adult females have dark gray upperparts with dusky
gray underparts, nape, and forehead. Juveniles resemble
adult females, but with whitish bellies. Males in their
first full spring and summer have darker collars than
juveniles and females, and show variable amounts of
blue-black adult plumage. In all plumages, Purple Martins
have notched tails.
Voice: The male's song is a series of
rich whistles and chirps, with some rapid clicks or
grating sounds. Females sing a chortling song with
descending whistles. Call notes, issued in a variety of
social contexts, include various whistles and chortles.
Listen to
Purple Martins
Purple
Martin Range Map
Purple Martins breed from southwestern
British Columbia south to Baja California; and from
northeastern and east-central British Columbia and
central Alberta to southern Ontario and New Brunswick
south to Mexico, the Gulf Coast, and southern Florida,
and west to eastern Idaho and central Utah. Local in the
Rocky Mountains but avoids most other mountainous areas.
Winters in South America, casually in Florida. Purple
Martins inhabit open and cut over woodlands, open grassy
river valleys, meadows around pools, shores of lakes,
marsh edges, agricultural lands, saguaro deserts, parks
and towns. Prefers habitats near open water. In the East,
breeds almost exclusively in artificial colonial purple
martin houses; in the West, still uses woodpecker-made
cavities to a large extent.