In the birding world, few species generate more excitement than does the "Purple Martin," a swallow that is arriving now in Florida, with reports of "scouts" logged almost daily online.

Purple martins, the largest of the swallows in North America, are totally dependent on man-made housing east of the Rockies and faithfully return to the same locations each year, so it's understandable that human "landlords" anxiously await the return of "their" birds from wintering grounds in South America.

Some of the earliest arrivals to North America trickle into south Florida as early as late December prior to the new nesting season and dates/locations are watched by martin enthusiasts throughout the breeding range in the eastern United States and in Canada. Arrivals are posted on an online database - atwww.purplemartin.org -- maintained by the Purple Martin Conservation Association (PMCA), a nonprofit conservation organization.

Initially arrivals in Florida tend occur in south Florida, but can occur randomly throughout the state well into the spring months. Among recent arrivals: Jan. 1 in Fort Myers, Jan. 9 in Plant City; Jan. 17 in Jacksonville and Jan. 23 in Tallahassee.

The first wave consists of so-called "adult" martins - those two or more years old, with adult males sporting full dark-purple color. Females are a bit drab, with a gray breast. One-year-old martins - called "subadults" -- arrive 6 to 8 weeks later than the older birds. These younger birds sometimes are more easily attracted to new housing locations.

Purple martins prefer to nest in colonies in gourds hung from large racks and in multi-compartment birdhouses. The birds nest throughout Florida with the only exception being in the Keys.

Purple martins feed on the wing - taking insects from the air - and early arrivals sometimes face the prospect of starvation when cold snaps clear the air of insects. Generally, purple martins spend the winter over a wide range of Brazil.
Whether the Florida population joins northern populations in the same wintering locations is unclear. This nesting season the PMCA will place "geo-locator" tracking devices on adult purple martins at select colonies in the state to hopefully learn more.

Purple martin populations overall in North America are holding steady - up in some states and down in others, based on long-term data from the NorthAmerican Breeding Bird Survey (BBS)- thanks to devoted men and women who erect and maintain housing.

Florida's purple martin population is more numerous than most states to the north - but has shown a steady decline over several decades. Because the species is totally dependent on human-provided housing, reduced numbers sometimes can be attributed to declining tradition of erecting housing in some localities.

But martins can be found throughout the state including colonies at parks and golf courses. Several well-maintained colonies are located at Epcot theme parks near Orlando. One of the most easily viewed is near the butterfly house. Fortunately for butterflies, martins tend to feed very high in the sky; butterflies very low, near to flowers.

Despite relative abundance of purple martins in Florida, many people try for years to attract them without success, or their colonies disappear. Hobbyists may be unaware that problems such as competition from invasive non-native birds -- European starlings and house sparrows -- or predation caused abandonment.
While generations of Americans have hosted purple martins - the custom adopted from Native Americans who hung out nesting gourds - specific techniques to help a colony thrive emerged in the past decade, based on research conducted by the PMCA and landlords in the field.

Among innovations are deeper compartments to protect nestlings from rain and aerial predators such as owls, specially-shaped entrance holes designed to admit martins while restricting starlings - and unique pole guards to thwart climbing predators: rat snakes and raccoons.

Because purple martins are birds of the open sky -- catching insects on the fly -- the PMCA's number one tip: place housing in the most open space available, but where the colony can be enjoyed and monitored.

More information about purple martins can be obtained from the Purple Martin Conservation Association - which is focused on aiding martins and landlords -- including an information and supplies booklet, with advice on attracting and managing a colony, and data sheets to participate in a "citizen science" program called Project Martin Watch, a national effort in which participants monitor nests and mail information to the PMCA at season's end.

To obtain the booklet, contact the PMCA at 814-833-7656 or online at www.purplemartin.org. The website also has an active online Forum, and many hobbyists participate in the group's Facebook page and Twitter account.