July 2001 V.65, N.7 

       When I moved to Marshall County in the summer of 1985, I was struck by the hayfields and pastures that dominated the ridge tops. I soon learned they had been timbered decades earlier and converted to farmland.

      What also struck me was that though I saw an occasional bluebird, I should have seen more. The ridge top habitat was perfect for bluebirds open, with just a few scattered large trees and minimal brush. What was missing, I surmised, were nesting sites.

      Eastern bluebirds nest in cavities old woodpecker holes or natural cavities. But they also take to manmade nest boxes like flies to honey. So I busied myself that first West Virginia winter building bluebird boxes. By mid-February, I had 30 in place, most on my property and a handful on a neighbor's farm.

      Since the mid-1970s, bluebirds have rallied from the brink of being endangered to becoming a relatively common and familiar country bird if cavities are available. For more than 25 years, bluebird lovers all across the country have built and erected nest boxes and the birds have used them. Ever notice those bird houses placed on fences along the interstate highways in West Virginia? They're for bluebirds. The comeback of the eastern bluebird, both statewide and nationally, is an impressive success story.

      To illustrate bluebird natural history, let me focus on one pair from that first nesting season, 1986. The story of nest box HM-4 began in February when I strapped it to a fence post on a neighbor's farm. It was one of four that I hung along the fence surrounding a large pasture. A metal baffle beneath each one protected the nests from hungry rat snakes and raccoons. By being placed in mid-winter, the boxes would become a part of the landscape and be more likely to be accepted by bluebirds (though it's never too late to put up a nest box).

      I first noticed bluebirds investigating HM-4 in early March. As I drove past the fence on my way to town, I saw a female leave the box. I stopped the car and watched. Moments later, the male landed on the box. Then the female returned and entered the box, and quickly the male joined her inside. After about a minute, the male emerged and once again perched on the roof. He watched as his mate flew to a nearby tree. This curious investigation of the box continued for the entire 30 minutes I watched.

      Ideally, a bluebird box should be hung four to five feet above the ground. The hole should be exactly an inch-and-a-half in diameter, just small enough to exclude starlings. The box should also be protected from below by a metal baffle to discourage predators. It should be placed at least 50 yards from the nearest wooded area, though it's OK if there are a few scattered trees nearby. And to minimize competitive squabbling with territorial neighbors, at least 100 yards should separate each box. At least that's this ornithologist's prescription for a successful nest box. HM-4 met all these requirements. Now I had a chance to see if these birds would do "what they were supposed to do."

      For the next two weeks, I saw the bluebirds every time I drove past the nest box. Sometimes they were perched on its roof. Sometimes they were hawking insects from a nearby snag or eating rose hips in a thicket. So far so good. What follows is a "diary " of events that I observed at HM-4.

      March 17 HM-4 contains a completed bluebird nest. It is made entirely of dried grasses and fills the box almost to the hole. The cup is lined with fine grasses, while the foundation consists of courser material.

      March 24 No change. No eggs.

      March 29 Two sky blue eggs rest in the nest. The adults are nowhere to be found. During the egg-laying period, the female visits the nest only early in the morning to lay that day's egg. This reduces the chances that a predator will see her near the nest and gives her time to feed in anticipation of the commitment she is about to make.

      April 1 As I drive by the box, the female leaves, so I stop to check the nest. Since the female is already gone, I know I'll not disturb her. The nest now contains five eggs, and they are warm to my touch. The clutch is complete and the 14-day incubation period has begun. I note the date so I won't disturb the nest again until just a few days before hatching. Incubating females are sensitive to disturbance during the first half of the incubation period and may abandon the nest if disturbed during this time.

      April 4 A late winter storm dumps 16 inches of wet, heavy snow on the area. I wonder how the bluebirds are faring, but resist the temptation to check.

      April 11 I approach the box quietly on foot, hoping to catch the female on the nest so I can band her. Late in incubation (this is the 11th of 14 days), females sit tight. Their investment in the nest has reached a critical stage, and they flee only if seriously threatened. I place one hand over the hole, and slide the other under the door, on top of the incubating female. I grab her firmly and band, weigh, and measure her. The entire process takes less than 60 seconds. Then I put her back on her five eggs, close the door and hold my hand over the hole for about a minute to be sure she has settled down. I walk away and she remains on the nest as if she was never disturbed.

      April 14 Right on schedule, four tiny hatchlings occupy the nest. The fifth egg is pipped and ready to hatch. Mom sits on the barbed wire fence and scolds me from just six feet away. Dad buzzes my head. I take the hint and leave. Within two minutes of my departure, the female resumes brooding the chicks.

      April 16 I park my car about 50 feet from the box and watch. A car makes a perfect blind when it's close to a nest. About every three minutes one of the parents visits the nest with a meal for the kids. Grubs and soft fleshy caterpillars seem the food of choice. In another week the chicks will be eating grasshoppers and other harder-bodied insects.

      April 26 The chicks are now 12 days old and ready to be banded. I use special pliers to attach a numbered aluminum band to one leg of each chick. (The U.S. Fish and Wildlife Service's banding lab issues bands only to licensed banders.)

       April 28 The chicks now fill the box and whitewash covers the walls. They will fledge in a few days, so this will be my last visit. Disturbing a box after chicks are 14 days old may cause them to fledge prematurely, making them easy prey for snakes, cats, raccoons, and other predators. Normally bluebirds leave the nest between 18 and 21 days of age.

      May 2 I notice several speckled juvenile bluebirds in the oak tree near HM-4. With my binoculars I can see their bands, and after scanning the branches, I count a total of five fledglings. Sweet success! Bluebirds raise two or three broods each year, so I remove the old soiled nest to be sure the box is free of debris and parasites before the next nest.Nothing I do gives me more satisfaction than watching a pair of birds raise a brood in a nest box I've provided, because I know that without my help, they may not have nested. It personalizes conservation for young and old alike.

       HM-4 proved especially rewarding because the same pair of bluebirds raised two more broods in it that summer. The last fledged in late August.

      To learn more about bluebird conservation and other cavity-nesting birds, contact Dawn Hale at the West Virginia Nongame Wildlife and Natural Heritage Program (P.O. Box 67, Elkins, WV 26241), or join the North American Bluebird Society (P.O. Box 74, Darlington, WI 53530; www.nabluebirdsociety.org)

      Dr. Scott Shalaway, author of Building a Backyard Bird Habitat, writes a syndicated nature column for newspapers around the state.

      Readers interested in Dave and Steve Maslowski's wildlife photographs may call them at (513) 231-7301 or e-mail MaslowProd@aol.com