Sharon Lovejoy

BLUEBIRDS AND PURPLE MARTINS

Sharon Lovejoy

It was love-at-first-sight when I saw my first glossy, purple martins plying the insect laden air for their breakfast. I felt the same when a flock of twenty two eastern bluebirds settled, like pieces chipped from the cerulean sky, into a grassy meadow below me. I knew, as I sat for hours watching the birds, that someday I would find a way to shelter them on my land. Now, my heart and mind are turned to a new garden and our plans are being sown for habitats and shelters for everything from foxes to spiders.

The other night, as my husband and I spread drawings and plans across our long kitchen table, we totaled the figures for all of the houses, roosts and plants we hoped to buy. I hadn't even mentioned my dream of a granite birdbath and Jeff had already started worrying about "budget" and other necessities. While he was worrying about food, I was focusing on soul food. Just as Imelda Marcos feels that you can't have too many pairs of shoes, I am sure that you can't have too many plants or nesting birds.

At a nursery, we found some huge wooden and metal apartment buildings for the sociable martins and about six different styles of bluebird houses, but the prices were staggering. Even if I could somehow "prune" a bit from my budget, there was no way we could ever afford to house all of the critters I hoped to welcome. A search for low-cost, alternative housing that was suitable for the birds and pleasing aesthetically began in earnest.

At Longwood Gardens in Kennett Square, Pennsylvania, I learned solutions to my problem of housing both martins and bluebirds. While our friend Dave Thompson of Longwood's Education Department was escorting us through the "Idea" garden, I photographed and coveted the plump gourd bird houses swinging gently from a tall gourd "rack." He told me I should talk with Section Gardener Bill Haldeman, who has been instrumental in developing and maintaining wildlife habitats throughout the grounds at Longwood. He said that if we were looking for successful, economical bluebird houses, we had to call Warren Lauder, a man he affectionately called the "Bluebird Man."

When we returned home from Longwood, I called Nichols Garden Nursery in Albany, Oregon, for a few packets of their gourd collection which included the bird house gourds, or Lagenaria, named for their plump, bottle shape. My hope was to grow enough of the gourds to provide housing similar to the "rack" at Longwood for a healthy population of the martins.

I compared notes with Bill Haldeman about the cultivation of the gourds. He told me that he grows his gourds in full sun in the corner of his compost pile and that the constant moisture and rich, well-drained soil makes the vines thrive. Usually seven or eight seeds are planted one inch deep in small hills about six or seven inches high. The hills are spaced about six feet apart to give the rambunctious vines room to gallop and roam.

Bill cautioned,"If you use too much nitrogen, you'll get lots of growth, but no fruit. You want to pinch off some of the developing fruit and try to grow four or five big, thick-skinned gourds. If you get some healthy ones, with good, thick skin, save the seeds for next year's crop. Don't save thin-skinned gourds; they'll crack and be useless."

I planted my gourds against a sunny fence and barn wall in the Heart's Ease Gardens. My first crop was seeded directly into a rich, deeply dug bed, but cool weather and a healthy population of slugs and snails defeated them.

My second packet of seeds were soaked in a cup of water for two days and planted in bio-degradable pots I made from newspaper. The paper pots were kept up on a bench in full sun and every evening I covered the seedlings with old jelly jars to keep them from being munched.

After the gourds were up and healthy, I transplanted them, pot and all, into the children's garden where they clambered and looped up the playhouse, over the walls, and into areas not meant for them. Pruning them encouraged branching and fruit production; the only problem was that I couldn't keep up with their exuberant growth. Next time I plant gourds I'll use trellising and old ladders for support and I'll only plant half a packet of seeds with only one or two plants for each hill.

Bill told me that he harvests his gourds after 140 days when the vines have shriveled and gone through a couple of frosts to "cure" them. I don't have frosts and waited until the vines had thoroughly browned and died back. Bill harvests them leaving on a few inches of the stem and stores them in a cool, dry garage for five or six months.

After the gourds are dry and rattle slightly when shaken, Bill cuts a two inch entry hole three to five inches up the side of the gourd and cleans out the seeds. With his pocket knife or a paring knife, he slightly enlarges the bottom of the hole 1/4 inch so that it is pear-shaped. He feels that this small modification makes it easier for the martins to carry nesting materials into the houses. No perch is necessary at the entrance hole; the Martins are able to enter easily without one, but aggressive birds, such as starlings, would happily use a perch to gain access to a ready-made home.

Bill uses a 1/4 inch drill bit to bore a series of holes around the top and bottom of the gourd to provide ventilation and drainage. A small hole at the very top of the gourd is strung with a plastic-coated wire hanger that can be attached to a gourd "rack" or to a plastic-coated wire stretched clothes-line style twenty feet above the ground with gourds spaced a foot or two apart. The hanging hole at the top of the gourd is generally drilled directly above the entry hole.

Purple martins are gregarious birds and prefer to nest in colonies, so a collection of at least a dozen gourds works best. Unlike many other species of birds who want to nest far away from humans, the martins seem to like their colonies to be within 100 feet of a dwelling, which makes martin watching, appreciation and protection easier.

I washed my gourds with hot, soapy water and used a residue-free copper sulfate 20 minute soak that Louise Chambers of the PMCA recommended. I confessed to her that I prefer the natural look of un-painted gourds and she said, " I do too, but the martins choose white gourds over the natural.

Entrance holes are easier to locate and the reflective white paint keeps interior temperatures much cooler."

Bill commented that martin houses shouldn't be hung until a month after the first martins have arrived in the spring. Hanging them too early encourages other species to compete for the gourds. He has found, through trial and error, that it is best to situate gourd houses at least 40 feet from tall trees and buildings so that martins have a clear air corridor for incoming and outgoing flights. Most martin enthusiasts agree that gourd racks or poles supporting the line of gourds should be sturdy, smooth wood with a four foot collar of tin or aluminum or a metal pole free of any vines or shrubs that could provide access to predators.

To alert the first, arriving martin males that some prime Longwood apartments are ready and waiting, Bill repeatedly plays a cassette recording of a male martin warbling the "Dawnsong," a loud, rhythmic melody distinctly different from their daylight singing. He said that the recording is the song of the dominant male in a nesting colony and that it can be heard over 30 square miles from the site! He plays his recordings for a few hours each day, beginning at 4 a.m., until the colony is settled. I can't wait to order my own copy of the tape from PMCA, but I know that my new neighbors may not be thrilled by the early morning serenade.

Once the gourds are occupied, they should be checked for nest crashers such as English sparrows or starlings. I asked if the swaying of the hanging gourds caused any problems for the birds. Bill said that Purple Martins actually prefer the free-swinging gourd houses to the typical and expensive ancestral homes in the hollowed-out branches of trees.

Bill said that the autumn cleaning and storing of the gourds is essential for their longevity. He has seen painted gourds that have lasted through 30 nesting seasons! Amazing that an inexpensive packet of seeds can provide decades of pleasure. Growing my own birdhouses helped alleviate some of the financial discomfort that can sometimes accompany the purchases of an overzealous gardener. Building birdhouses is another solution for someone who loves the idea of providing homes without spending themselves out of their own. But, building a birdhouse is not as simple as it sounds.

All of a bird's nesting requirements must be taken into consideration. What size entry hole fits the species you wish to attract? Are you mounting the house in the proper habitat and at the correct nesting height for the bird? Is the house well ventilated and easy to clean? Is the house free of cracks and openings that will allow the rain to enter and dampen nesting material and chicks?

Armed with a stack of bluebird information Dave Thompson sent to me, I waded through a sampling of 361/2 years of extensive field work done by Warren Lauder, respected bluebird conservationist. After reviewing his simple, logical bluebird house plans, we decided to devote some time to building a few. But, before we started building, we had a question about the plans, which inexplicably called for the pine-roofed house to be finished with a dark, asphalt shingle.

Mr. Lauder, who was very modest and quiet about his tireless years of bluebird work, was outspoken and confident about his perfected house plans. He explained that bluebirds are secondary cavity nesters (that means they occupy cavities, but are incapable of creating them) who were displaced and threatened when introduced English sparrows and starlings took over their tree-hole nesting sites. He became aware of the plight of the bluebirds in 1960 when he realized how drastically their numbers had declined. He began to read everything he could find about the bluebirds and the new nest boxes being built to save them.

His detective work pointed out the flaws in the boxes being constructed. Rain entered the houses and chilled the nestlings, the heat of summer sometimes killed the embryos in the second and third clutches of eggs, and chicks often died from heat and parasites. Working with a friend from the Engineering Department at DuPont Company, he re-engineered the traditional nesting box so that his design is the "only bluebird house with a positive air exchange when it is needed."

I asked him to explain how his nesting box differs from others. He said that he builds his houses of white pine which has not been painted or finished. He drills vent holes near the top of the box, a 3/8" vent hole in the floor, and each corner of the floor is cut at a 45 degree angle creating holes to further increase air circulation.

The "Bluebird Man" also re-designed the front panel lowering it slightly to provide a long slot vent. He hinges the front panel with one nail on each side of the box, making it easy to lift up for monitoring nestlings and cleaning the boxes between clutches of eggs.

While most bluebird plans call for a roof overhang of only 1 to 2 inches, Mr. Lauder's roof overhangs 1 3/8 inches on the sides, 1/2 inch on the back and 3 3/4 inches on the front. The wider overhang shields the nestlings from extreme heat and rain and the probing hands of predators. Inside, deep cross-hatched cuts in the front panel enable fledglings to climb to the entrance hole. All of his houses are mounted five to seven feet high on metal fence posts or pipes and are kept 100 yards apart.

"My houses have the traditional 3/4 inch thick pine roof, but they are topped off with a dark asphalt shingle." At this point, I interrupted Mr. Lauder and told him that the shingle was the one thing that hadn't made sense. He chuckled and said, "the heat build-up on the roof causes the air to rise and exit through the vent holes creating a vacuum which pulls the outside air through the cut-off floor panel. That is what I mean by a positive air exchange. It keeps the temperatures tolerable for the chicks!"

The "Bluebird Man" didn't have to give me any more explanations. His successful houses have dramatically and significantly increased the population of bluebirds wherever they are used. We hope to add our gardens to his long list of bluebird success stories.

Our clothing, food and survival budget has barely been impacted by my long list of garden "necessities" thanks to the help of Bill Haldeman and the "Bluebird Man." Because of them, I'll have both food and soul food every spring and summer morning when the martin warbles a dawnsong and the bluebirds sing what Thoreau described as a "soft, flowing, curling, warble." A hundred pairs of shoes aren't worth one of those mornings.

Note: Some modifications in entrance holes will be needed to accommodate the western and mountain species who require different entrance hole dimensions.

RESOURCES:

For bluebird house design and information send $1.00 and a #10 SASE to:

Warren H. Lauder-The Bluebird Man

405 Pierre Drive

Kennett Square, PA 19348

For gourd seeds:

Nichols Garden Nursery

1190 North Pacific Highway

Albany, OR 97321-4580

(503) 928-9280

Catalogue is free

For purple martin information, blueprints for gourd racks, gourds, seeds, "Dawnsong" tape:

Purple Martin Conservation Association

Edinboro University of Pennsylvania

Edinboro, PA 16444

814-734-4420

For a complete listing of all bluebird societies write to:

North American Bluebird Society

Box 6295

Silver Spring, MD 20906

Request their North American Bluebird Trail Directory

For continuing education classes on bluebird nesting boxes and banding:

Longwood Gardens

Continuing Education

P.O. Box 501

Kennett Square, PA 19348-0501