The call of the upland sandpiper is one of the eeriest sounds in nature. A long wailing whistle that rises and then falls, it has been called as sad as a November wind, and indeed it does sound more like the wind than the cry of an animal.

Sometimes the bird delivers its lonely cry from high in the sky, so high as to be nearly invisible to an observer on the ground. On quiet days the sound can carry a mile.

A century ago, that call was one of the characteristic sounds of spring in rural Illinois. By day, the birds called from the cow pasture. By night, vast flocks of migrants passing overhead cut the dark sky with their cries.

The call is rarely heard in Illinois now. The upland sandpiper, a victim of a combination of ruthless hunting and habitat loss, is on the endangered list in this state. Only a few scattered populations remain.

We have a few birds in far southern Cook County in some old fields that have been taken over by the Forest Preserve. The largest concentration in the state, over 100 adults on the average, lives at the Joliet Arsenal, the Army munitions plant just off I-55 in Will County.

The arsenal dates from World War II. Its main function is the manufacture of artillery shells. During the Vietnam War, it operated 24 hours a day. Currently, it is in mothballs, although security remains tight.

Most of the arsenal is vacant land, which the Army rents to local farmers as pasture for cows. The sandpipers live in the pastures. For the past three years, the Illinois Department of Conservation has been censusing these birds at the beginning of the nesting season, and this year, I went along on the first day of the three-day count.

You need three things to do a survey of nesting birds: good eyes, good ears, and a willingness to get up at the most ungodly hours. Bill Glass, a heritage biologist for the DOC, had invited me to help with the count and had given me instructions to meet him near the arsenal at 5:30 AM. To get there on time, I had to leave my house on the north side at 4 AM, which meant getting up at 3:30. Science is a demanding profession.

There were six of us on the count. Bill, Francis Harty, and Maggie Cole all work for the DOC’s natural heritage division, the organization responsible for overseeing natural areas and endangered species. Ray Marshalla is a wildlife biologist at the Des Plaines Conservation Area, and Bob Montgomery is a biologist with the Max McGraw Wildlife Foundation in Dundee.

The usual method used on counts like this is to lay out a route through the area you want to cover and then drive or walk the course, stopping at regular intervals to look and listen for a uniform period of time, in this case, four minutes. At each stop, one person serves as a sort of recording secretary, writing down names and numbers of birds seen or heard. While the sandpipers were our main objective, we recorded everything we encountered.

For most of the morning, we split up into two groups. I went with Bill Glass and Bob Montgomery in Bill’s pickup truck. Bill and I rode in the cab of the pickup, while Bob rode standing up in the bed. During the stops, we each faced in a different direction and concentrated our attention on what was in front of us.

Bob Montgomery is one of these amazing people who can identify the call of any species almost before the bird opens its beak. Not just identify it, but tell exactly where it is. I am much slower, and when I hear a buzzing trill, I have to listen very carefully and think a bit before I decide between a grasshopper sparrow and a savanna sparrow. I envy his ability to locate the source of the sounds. Having left part of my hearing on the rifle range in boot camp and other parts at Grateful Dead concerts, I always have great difficulty figuring out where noises are coming from.

We were finding lots of birds. Close to 30 upland sandpipers, as well as good numbers of eastern meadowlarks and a few grasshopper and savanna sparrows. The hedgerows that bordered the pastures harbored brown thrashers, robins, and song sparrows. For a brief moment, we thought we had seen a loggerhead shrike, another member of Illinois’ depressingly long list of endangered species, but a closer look revealed that we had seen a mockingbird.

And we saw a whole lot of cows, most of them standing, staring, and chewing, the things that cows do best. According to Bill Glass, the cow is an indicator species for the upland sandpiper. You rarely find the bird without also finding the bovine.

The original centers of abundance of upland sandpipers were the shortgrass and mixed-grass prairies of the Great Plains. The tall-grass prairies of Illinois were too lush to suit their tastes. Here they were almost certainly confined to the sparser prairies growing on infertile sands and gravels or to areas that were being heavily grazed by our native cow, the bison.

Upland sandpipers are ground nesters. Their usual clutch is four eggs, and, like other sandpipers, they are born with a covering of down and are able to run and find their own food immediately after hatching. The parents lead the young to food and provide some protection from predators, but the chicks are otherwise on their own. Over 90 percent of their diet is insects, with fruit and seeds providing the remainder of their food.

We think of them as North American birds, but their annual stay here is really quite short. They arrive at this latitude in late April, and some of them start back south as early as the middle of July. They are all gone by the end of August. Their winter home is on the pampas of Argentina, half a world away from here.

They average about 12 inches from tip of beak to tip of tail. Their plumage is mottled brown-and-buff above and white below. They are long tailed, for sandpipers, and their most distinctive trait is a small head, a characteristic that gives them one of their nicknames: prairie pigeon.

Their history over the past couple of centuries provides an excellent example of the enormous effects that human actions have on the other living things that share our planet. Initially, the arrival of Europeans, in North America produced a population explosion among the sandpipers. Every time a settler felled a piece of forest and replaced it with a cow pasture he was creating brand-new upland sandpiper habitat. The birds expanded their range as far as New England, not only moving into new territory but becoming one of the most common birds in their new homes. But the expansion was only a temporary boom. We were just fattening them for the slaughter.

In a curious way, their fate became entwined with that of the passenger pigeon. When the pioneers cleared the woods to make pastures, they were destroying passenger pigeon habitat. That habitat loss, combined with the greed of commercial hunters, led directly to the extinction of the pigeon.

With no more passenger pigeons to shoot, the hunters turned to the suddenly abundant upland sandpiper as a new source of meat. Unfortunately, the sandpipers tasted great, and they couldnt have been very filling, since a live bird weighs only five or six ounces. Remove the feathers, feet, legs, beak, and viscera and you are left with the equivalent of two or three Chicken McNuggets. The hunters shipped them by the boxcar load.

And as conservation laws began to curb the slaughter, the sandpipers got hit by land-use changes that cost them big pieces of their habitat. In the east, farmers on land that was less than the best were being driven out of business. Much of their land reverted to forest where the sandpipers could not live.

Here in the midwest, the old-style generalized farm, which included pastures and hay fields, was almost completely replaced by specialized operations producing only corn and soybeans. The sandpipers could not find a home in plowed ground and they simply vanished from most of their former range.

At the Joliet Arsenal, Bill Glass is overseeing a project that might help them come back in some areas. About 100 acres of land there, land that grew corn until recently, has been planted with a mixture of imported bluegrass and native prairie grasses–50 acres of bluegrass, 50 acres of prairie grass.

Bluegrass is a cool-season grass that does its growing in spring and early summer and turns brown in August. The native grasses–Indian grass and big and little bluestem–are warm-season grasses that start growing later in spring, and thrive on the hot, dry weather of July and August. Ideally, the combination will provide good grazing from April through October and good upland sandpiper habitat as well. If it works, farmers may have more reason to turn some of their land into pasture, and the sandpipers may reoccupy some of their former habitat.

In the meantime, the birds may be showing a behavior change that could help their cause. Bill Glass told me that the literature on upland sandpipers describes them as requiring large nesting territories, 40 acres or more per pair. At Joliet, the population density is several times that great. It is almost a colony by upland sandpiper standards. Perhaps the birds are learning to make the most of the little land they have left.