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Vol. LVIII, No. 3
February 10, 2006

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The Birdman of Bldg. 22
Red-Tailed Hawk in Residence at NIH

The Perimeter Security Fence, a sign of the times, may have its detractors, but there is something ecologically positive about those steely bars — something you might not have noticed.

And that something is underbrush — at least in a 4-acre test plot between the Children's Inn and the new fire station.

Photo courtesy of Steve Pinker, Harvard University  

As Lynn Mueller, chief of grounds maintenance and landscaping, Office of Research Facilities explains: "At NIH, we have a park-like setting where the grass is mowed, but as some areas are restored to a more natural state, underbrush will grow up attracting a greater variety of songbirds, including many that are ground nesters."

The perimeter fence helps in that restoration, since it bars pedestrian "cut-throughs" — and deer cut-throughs as well — which helps keep underbrush, well, brushy.

And that's not all. Grounds maintenance crews who gathered leaves from the many shade trees on campus dumped these leaves, creating natural forest duff — organic litter on the forest floor — into that restored area. This has created shelter for voles, moles and other critters favored by another natural denizen of NIH — the red-tailed hawk.

"He, or she, has been around here for about 10 years," says Mueller, who has been employed at NIH since 1979. "I was certain that it was a red-tail when I spotted it in our oak tree outside of Bldg. 22. Our guys would see him nail a pigeon right in front of everybody."

The red-tailed hawk (Buteo jamaicensis) is known for its eerie, high-pitched cry. If you ever saw Northern Exposure, it opened with the sound of its call.

"It's a shriek, really," says Mueller, who, while he modestly denies being an expert, is a long-standing member of the local Audubon Naturalist Society and has informally studied birds since he got his "bird badge" as a Boy Scout. At last count, he had catalogued 48 birds that inhabit the NIH campus.

"By 'inhabit,'" he says, "we mean that they either feed or nest here. That red-tail was out a lot in spring 2004 when the cicadas hatched, but normally they feed on songbirds (pigeons), squirrels and small rodents. And since the squirrel population has recently crashed for unknown reasons, and since we've had to net our building against roosting pigeons, the hawk may have gone over to Rock Creek for mice and voles."

That could be changing, though. The hawk was spotted one recent morning, perched atop Bldg. 45, shrieking away, and for what? Looking for his mate, or just a snack?

One employee reported that she's seen him fly past her window in Bldg. 31. "I thought it was a plane landing," she says.

With a wingspan of 48 inches, the bird is truly plane-like. The mature red-tailed hawk also has a short, hooked bill, strong claws, a white breast and a ruddy tail. Youngsters are less colorful.

Red-tailed hawk. Photo courtesy of Greg Vogel, Fermilab  

"They have binocular vision, too," says Mueller, who thinks the hawk's eye may perceive light wavelengths in mouse urine as "a glow they can see even through the grassy tunnels."

He's also engaged in an ongoing project to plant native species of fruit and nut trees, helpful in attracting squirrels and songbirds, which are part of the hawk's diet. Although he's not all about the predator — Mueller is a big squirrel fan, too.

"They're little comics," he says. "They have all day to figure out how to defeat a bird feeder."

Meanwhile, he's created projects to reduce pesticide use yet control insects by establishing songbird nest boxes on the NIH and NIHAC campuses and specialized nesting sites for bluebirds and kestrels at NIHAC, NIH's Poolesville facility.

So why should NIH scientists, many of whom don't study things that are bigger than a cell, be interested in a raptor, a bird of prey? Well, for one thing, the hawk is a good neighbor. It helps us humans by keeping down the rodent population — always a plus.

The hawk's perception may also resonate with a certain kind of scientific inquiry.

The Oneidas, one of the six nations that make up the Iroquois (Haudenosaunee) Confederacy, have studied hawk and eagle hunting technique. When a hawk sees a mouse, he dives directly for it, as opposed to an eagle, who sees the whole pattern and detects movement within it. Is there some correspondence here with the scientific mind, in its tenacity, its focus and its creative leaps?

For sure, the hawk is beautiful and strange, soaring high above the ground, where it can spot a mouse at a hundred feet, or locking talons (like holding hands) with another hawk in a mid-air courtship dance.

Spring's coming. Be on the lookout, and listen for that eerie cry.

For more information about the red-tailed hawk, contact the Department of the Interior, U.S. Geological Survey, Patuxent Wildlife Research Center, Patuxent Bird Identification InfoCenter at

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