Wild Lives

Magpie is synonymous with moxie

02-01-2004 // Gary Turbak

AS DEBORAH BUITRON climbed toward the magpie nest, its owners took strong vocal exception to her presence. In defense of their six eggs, the adult pair scolded loudly as they hopped among the pine branches just a few feet from the biologist. Then the male bird became even more assertive, landing on Buitron's head and delivering a few quick pecks of punishment. When she moved, the bird returned to the branches, but Buitron kept an anxious eye on it as she quickly checked the eggs and descended 20 feet to the ground. The encounter drew no blood, but it did confirm the bold behavior of a most remarkable bird.

Although long ignored by scientists, magpies have in recent years caught the attention of a few researchers, who have begun to paint a fascinating portrait of these scavengers. Magpies boldly assault predators that could otherwise easily make a meal of them. They steal each other's mates, move their own eggs into neighbors' nests and even exploit 1,200-pound moose. "Magpies have a great deal of personality," says Buitron, an adjunct assistant professor in biological sciences at North Dakota State University. "They're intelligent, active, curious birds." They also, researchers have discovered, do not deserve their reputation as wanton killers of songbirds.

The world's two magpie species are members of the same family as crows, ravens and jays. The black-billed magpie exists throughout the Northern Hemisphere, including much of Europe and Asia. In North America, this bird's densest populations are in the Rockies from Alberta to New Mexico.

Meanwhile, the very similar yellow-billed magpie exists only in parts of California. This species' range is probably restricted by its preference for a warm climate and intolerance of cold weather. Black-billed magpies, conversely, can tolerate the cold but not extreme heat.

Magpies have long been burdened with a reputation as brazen, brassy pests that reportedly kill barnyard fowl, young grouse and other birds. A century ago, many states offered bounties for dead magpies, and thousands (150,000 in Idaho alone) were poisoned or otherwise killed. But, says Buitron, "the bird's reputation is more negative than the facts merit. They do a lot of good by cleaning up carrion, eating insects and catching rodents." Today, magpies are protected by federal law in the United States but not in Canada.

Another rap against magpies is their supposed penchant for plucking songbird young from their nests. In 1991, however, researchers at the University of Sheffield in Britain analyzed that nation's bird count data from 1966 to 1986 and found magpies largely innocent of this charge. "Overall, there is no evidence that magpies have any impact on songbird populations," says Tim Birkhead, one of the researchers.

An adult magpie is about 20 inches long, with half that length devoted to tail. Both sexes look alike, although males are slightly larger. They do not migrate. And because magpies are not strong fliers, they spend much of their time on the ground.

Some magpies cultivate a unique food source by plucking ticks from deer, elk and other large animals. The ungulates, which appear to welcome magpies on their backs, are groomed and the birds are fed. (While the ticks prey on mammals, they apparently do not bother magpies.) This can be an important magpie food source.

But the magpies may be pulling a fast one. In 1990, William Samuel, professor of zoology at the University of Alberta, discovered that magpies often cache live and uninjured ticks rather than eat them. The birds likely forget about many of these stashes, leaving the ticks in a perfect place to reproduce. "However unknowingly," says Samuel, "magpies may be enhancing tick numbers for the next year by caching a lot of them."

During her studies of the birds in South Dakota, Buitron recorded more than 400 interactions between magpies and predators--often with magpies as the aggressors. Called "mobbing," a magpie assault usually involves several of the birds alternately dive-bombing the enemy, occasionally even striking blows.

Buitron once watched as magpies mobbed a coyote. While the threatening dives of several magpies kept the coyote pinned down, another of the birds landed a few feet from the predator, walked up behind it and gave a yank on the coyote's tail. The coyote beat a retreat, with magpies in hot pursuit.

Soon after magpie young learn to fly, the entire family may mob crows, squirrels and other predators that present a threat only to eggs and nestlings. Why attack when there is no immediate danger? "I believe the magpie parents are teaching their young how, as well as who, to mob, starting with much less dangerous enemies," says Buitron.

In 1981, researchers Chuck Trost and Cheryl Webb discovered another example of magpie chutzpah. Part of their project involved marking magpie eggs, and they knew that an egg or two often disappeared inexplicably from a nest. Still, the Idaho State University scientists were surprised by where some of the eggs were going. One day, a check of nest number 921 showed that egg number three, which had been there the day before, was gone. Incredibly, the researchers soon found that egg nestled nicely among others in magpie nest 206, some 70 yards away. The likely explanation? That magpie parents sometimes perform the rare and physically tricky feat of moving their own eggs to a competitor's nest. "With this strategy," suggest the researchers, "a bird could produce at least some offspring rather than suffer total loss from a predator or nest abandonment."

Magpie moxie also extends to courtship. Although a magpie pair might remain together their entire lives (six to seven years is not unusual), males often do pursue other females. While his mate is fertile, a male accompanies her everywhere. But once incubation confines his mate to the nest, a male is likely to go off in search of others to mate with.

Birkhead tells of one male that fell asleep while his mate fed a few yards away. When the bird nodded off, a neighboring male approached and mounted the female. Upon awakening, the sleepy bird drove off his competitor. The next day, he began building a new nest. "I suspect that the male started a new breeding attempt so that he did not have to risk rearing the offspring fathered by his next door neighbor," says Birkhead.

In another fascinating display, magpies may occasionally surround a dead member of a flock in what can appear to human eyes as a ritual gathering. One morning in 1988, birding enthusiast William Miller in Alberta, watched through a window as a magpie rose up from the ground to about 30 feet, and then died in midair and fell back to the ground. Within minutes, more than a dozen of the birds gathered in a circle a few feet from the dead one. A couple of them pecked at the corpse, while the others milled around it. Then the flock flew away. "It certainly had the characteristics of a ceremony," recalls Miller, an accountant. He coauthored a report of the incident with Mark Brigham, a University of Calgary biologist at the time who did not witness the event, in a 1988 edition of Murrelet.

The birds' motivation was probably not spiritual, however. According to Birkhead, such gatherings may warn of possible danger. Or the assemblage may spread the word of a new territorial opening. Whatever the reasons, he says, "Magpies do indeed recognize dead members of their own species and respond to them in a dramatic way."

With behavior as stunning as its appearance, the magpie is not likely to shed its image as one of the most audacious members of the avian community.

Montana writer Gary Turbak's article on grazing allotments also appears in this issue.

 

What Is the Smartest Family of Birds?

Are some birds smarter than others? No one knows for sure, but many experts believe that the magpie and its cousins in the Corvidae, or crow, family seem to display the greatest levels of intelligence in the bird world. Researchers have found that ravens, jays, nutcrackers and other corvids have the largest cerebral hemispheres in relation to body size of all birds. They are known for their ability to manipulate objects, such as opening and closing latches and tying knots.

In captivity, crows have learned to count and read clocks--skills that involve high levels of concentration. In the wild, ravens use at least 30 distinct calls to communicate with each other. They also can vocally imitate other animals. Blue jays, meanwhile, appear to have remarkable memories, enabling them to recall where they have cached thousands of acorns. "Corvids," observes one scientist, "are less restrained by instinct than other birds."

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