Our Window on Nature

. . . exploring the world around us

A Bird in the Hand

Filed under: Birds — Lowell Christie -- May 15, 2006 @ 3:25 pm

Canada Warbler - BandingWatching birds through binoculars is one thing, but if you really want to get a good look at our feathered friends, spend a weekend with a bunch of birdbanders.

Birdbanders are serious about their hobby, and for the most part they work alone. Either on their own property, or at a nearby favorite place, these “hands-on” ornithologists set up their equipment and obtain information that greatly increases our knowledge about birds.

But birdbanders don’t spend their entire lives in solitude. Occasionally they join forces in a combination banding expedition and camp-out, which they naturally call a Birding Band-0ut. For 22 years, the Michigan Bird Banding Association has gotten together at Port Huron each May. Last year our birding buddies, Bob and Margie Rogers, invited us to join the party. How could we resist?

The dust had hardly settled around the rigs before eager birdbanders hauled out their machetes and set to work, hacking away the brush and placing their nets. Many songbirds migrating toward nesting grounds farther north are easiest caught in “mist nets.” By the time our friends had finished their preparation, the area looked like a series of volleyball courts, except that the netting is finer and the poles are set up in narrow lanes cut through the brush.

The unsuspecting birds flit across an opening and get tangled in the net. Only their dignity suffers, since the banders check their nets regularly and untangle the birds for banding.

In the few-minutes wait before the next phase began, we had a chance to learn some of the reasons for bird banding. Much of what is known about bird migration and behavior has resulted from studies of banded birds. The major “flyways” have been mapped, along with the migration schedule kept by each species of bird. More local patterns have been defined as well. The movements of banded birds are charted to determine the size of their nesting and feeding territories, and to find patterns of dispersal after nesting is complete.

When it was time to check the nets, we tagged along. What a mess one small bird can make as it struggles to free itself from confinement. The banders work carefully, ever so gently loosening each bird from the net. A good bander, of which we saw many, can hold three or four warblers in each hand, with the birds’ heads safely tucked between fingers, bodies calmed, feet kept from flailing out and scratching their captor. Their least favorite birds to band, the workers told us on the way back to camp, are hummingbirds and grosbeaks. The tiny hummers get so tangled in the net that it’s almost impossible to free them, and their legs are so tiny that the bands are difficult to place. The grosbeaks are so outraged that they peck at any portion of human anatomy that’s available.

You don’t just slap a band on a bird and let it go. Each bird must be identified by sex and by species (a real challenge in the case of some Empidinox flycatchers). But that’s not all. The banders then try to determine the age of the bird by such esoteric differences as the color of the inside of the mouth. After entering all the information in a log book provided by the United States Department of Fish and Wildlife, the correct size of band is selected, its number recorded, and placed on the leg of the bird. The bands of aluminum alloy are feather-light, necessary for a bird that weighs only a few ounces.

Some of the birds caught had been banded previously. Banding studies show that many birds have a strong territorial affinity, returning each year to the place of their birth to mate and rear their own young. We saw evidence of this behavior, since the nets produced several birds banded by this same group a year or so before.

The banders forward their records to the Department of Fish and Wildlife in Laurel, Maryland, which administers and coordinates the program. Should any of the birds ringed on this weekend be either recaptured or later found dead, the banding information would be sent on to Laurel and a report mailed to the bander. Around the evening campfires, we heard tales of bands being returned from Mexico and the West Indies where the warblers had gone to spend the winter, and of other birds that had been recaptured more than a decade after banding, and yet they turned up almost at the original capture site.

Once the birds had completed their ordeal, they were gently released and allowed to return to the wild. Sometimes they flew away in a huff, but occasionally the birds seemed disoriented, and spent a few moments in an open hand or just stood on the ground looking around. But it wasn’t long before each feathery mite had resumed his search of food, none the worse for making an involuntary contribution to science.

Songbirds aren’t the only avians that are banded, of course. Every migrant species is banded by some part of the 3,500 member banding fraternity. Of all ages and both sexes, birdbanders have placed their metal rings on more than 1.5 million birds since the project officially began back in 1920.

And not everyone can band birds. A license is required, and it goes only to those who can prove that they know enough about birds to be able to identify them correctly, to handle them properly, and to keep accurate records. At the Band-Out we saw banders thoroughly enjoying their avocation. But we realized that they appreciate the importance of their work, and the need for meticulous records if they are to be of scientific value.

It’s not a casual commitment, this banding of birds. Not long before coming to the Band-Out, many of these same people had spent a week at Whitefish Point, on Michigan’s Upper Peninsula. But, instead of warblers, they were after hawks and owls. Stronger mist nets were necessary for these larger birds. Occasionally traps are used. But it was the capture of predators such as these that helped to indicate the serious damage being caused by the insecticide DDT.

Banding studies of hawks, eagles, ospreys, and owls – birds that feed high on the food chain – showed that their numbers were decreasing dangerously in the 1960s. And DDT was the culprit. The chemical concentrated in the bodies of these birds, and they acquired more with each mouthful of contaminated meat. The unhappy result was birds laying eggs with shells so thin that they shattered under the weight of the parent.

Today there’s a success story to report, as raptors begin to reclaim areas once swept free of their presence. How do we know? One way is by very carefully monitoring these creatures that most of us see only from a distance. And the best way to do it? By banding birds, of course.

FMC584

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