Return of Purple Martins delights their human landlords each spring10:20 am | March 26, 2012
In the birding world, few species generate more excitement than does the Purple Martin, a large swallow that is arriving now in Tennessee, 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 Tennessee trickle in by late February, and dates/locations are watched by martin enthusiasts nationally on an online database at www.purplemartin.org that is maintained by the Purple Martin Conservation Association (PMCA), a nonprofit conservation organization.
The earliest arriving martins recorded in Tennessee this season was Feb. 17 in Adamsville and in South Pittsburg. Among other early arrivals: Walnut Log on Feb. 23 and Knoxville on March 3.
The first wave of arrivals 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 “sub adults” — arrive six to eight weeks later than the older birds — pushing their return well into May. 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 Tennessee with the greatest populations west and central, with substantial but fewer colonies in the mountainous east.
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. However, hobbyists have learned to supplemental feed purple martins during cold spells.
A PDF information sheet about supplemental feeding — the techniques are still new to many hobbyists — can be found at the PMCA’s website at www.purplemartin.org. Although once believed improbable, it’s been shown that purple martins — when no other food is available — will learn to accept crickets, mealworms and even bits of scrambled eggs flipped high into the air, and placed on high platform feeders or inside nest compartments.
The PMCA recently analyzed long-term data from the North American Breeding Bird Survey (BBS) and found that — thanks to devoted men and women who erect and maintain housing — Purple Martin populations overall are holding steady in North America — with exceptions in some states — and appear to be slowly increasing in Tennessee.
A rural Amish community, Ethridge, in Central Tennessee, may well have the most martins in the state, with colonies located on many of the farms, as well as in many yards in nearby Lawrenceburg.
Purple Martin colonies can be found in several Tennessee parks and nature reserves, including Warner Parks Nature Center and Shelby Bottoms Nature Center in Nashville, and Lichterman Nature Center, Memphis.
Purple Martins gather in massive roosts in late summer in preparation for fall migration. One of the largest in North America is on an island in Dale Hollow Reservoir, which straddles the Tennessee-Kentucky line. Some martin enthusiasts who have visited the roost believe it may contain upwards to 100,000 birds in early August. The roost can be viewed at sunset — when massive numbers of the birds descend into the trees — from Lilydale Campground. Nearby Willow Grove Resort also hosts a large colony in traditional wooden houses.
Despite relative abundance of Purple Martins in Tennessee, 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 Forum, and many hobbyists participate in the group’s Facebook page.
Judith Beckman, who lives on Spivey Mountain in Unicoi County, called me last week to ask for a means of bringing peace to her warring Eastern Bluebirds and Tree Swallows. She is hosting both of these cavity-nesting birds and provides nesting boxes for their use. She would like for the two species to co-exist, but so far has noticed that the Tree Swallows out-compete the Eastern Bluebirds.
She has already tried spacing their nesting boxes apart, but that doesn’t seem to have brought about a truce. I didn’t have a good suggestion but thought I would ask readers to share any ideas they might have.
I have hosted both Eastern Bluebirds and Tree Swallows for several years. I typically have a single pair of each of these birds nesting in the fields near my home. The Tree Swallows usually stake out the boxes closest to the fish pond.
Donald Rice emailed me to report that his first bluebird showed up and immediately started building a nest in a recently hung birdhouse this past weekend.
In addition, two Brown-headed Cowbirds have been showing up, feeding on the ground and feeder. They seem to go for the cheaper mix birdfeed that Don puts out for the doves, instead of the sunflower seeds.
“Sparrows are building nests everywhere,” he informed me in his email. “A pair are trying to build inside a bell I have hanging from the porch. Another pair have built their nest inside a cardboard box in the carport.”
He added that last year they built a nest around a spare Model A carburetor he had on an outside shelf.
He’s feeling quite good that of four new birdhouses he put out this year, two have already been claimed for the spring!
I’m also glad to report that I have finally observed some new arrivals at home on Simerly Creek Road in Hampton. Red-winged Blackbirds are back as well as Eastern Phoebes. Both of these species arrived overnight and gave me the first indication of their presence by persistently singing and calling. The Eastern Phoebe, in particular, calls persistently, especially in the early morning hours.
The next few weeks should bring many other spring arrivals. There’s also an upcoming bird walk open to the public. I will be helping to lead the walk with fellow members of the Lee and Lois Herndon Chapter of Tennessee Ornithological Society at Tipton- Haynes Historic Site in Johnson City on Saturday, March 31.
The walk, which is free and open to the public, will begin at 8 a.m. at the Visitors Center. The facility is also providing light refreshments for “early bird” arrivals. Bring binoculars to increase your viewing enjoyment. The walk is part of the celebration of André Michaux Day at Tipton-Haynes Historic Site.
This walk also offers an opportunity to view early-blooming spring wildflowers as well as birds.
To share a sighting, make a comment or ask a question, give me a call at 297-9077 or send an email to email@example.com. I’m also on Facebook.