Part 9

Taking the Annual Count

One of the joys of visiting the national parks, author Freeman Tilden once said, is having an unexpected, provocative experience. You go to a park to see or do one thing, and you come across something else that strikes your fancy as well. Tilden called it serendipity. At Agate Fossil Beds National Monument, one such experience might be birdwatching. In this piece, Doris B. Gates writes of her annual bird surveys in this area.

In western Nebraska the northern part of the Great Plains ends at the Pine Ridge, an escarpment circling from Wyoming across Nebraska’s north edge and winding into South Dakota. A major grass of this mixed prairie is little bluestem, Nebraska’s state grass, whose rusty-red hue in fall and winter gives much of the state its characteristic color.

These plains are rarely broken by cultivation and only a few houses with their few trees break the landscape. The land’s major change comes where the Niobrara River, here little more than a narrow creek, cuts a valley whose rock outcroppings provide homes for rock wrens, chipmunks, and bushy-tailed wood rats better known as pack or trade rats.

Here, since 1967, near Agate Fossil Beds National Monument, my partner and I have taken part in the annual Breeding Bird Survey for the U.S. Fish and Wildlife Service. Part of one of our survey routes, Highway 29, crosses the monument’s west end. We know the area—in June at least—quite intimately, when there is nothing quite so beautiful as a sunrise over these flower-dotted, green-grassed rolling hills along the Niobrara.

We go many kilometers and make many bird counting stops, then we drop into the little valley where the Niobrara flows and suddenly we hear and see birds in such rapid succession that we have difficulty getting them all named in the three minutes allowed us under the survey rules. Actually, three stops are influenced by the river: on the south edge we have found a common nighthawk, a lark sparrow, and a Say’s phoebe; on the north end the rock wren sings its un-wrenlike song. Near the bridge, where a narrow belt of shrubs and trees—mostly willows—hugs the river, we have logged the following: common flicker, a red-headed woodpecker, eastern and western kingbirds, western wood peewees, a blue jay, black-capped chickadees, house wrens, a brown thrasher, robins, yellow warblers, black-billed magpies, common grackles, black-headed grosbeaks, American goldfinches, and the non-native house sparrow and starling. Only once did we see or hear a black-billed cuckoo.

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If we stop and peer into a large culvert under the highway we may scare out a cloud of cliff swallows whose mud nests are stuck on culvert walls. Barn and rough-winged swallows are more rarely seen—usually near the Agate buildings.

Near scattered farmhouses we may see logger-head shrikes; by one water tank we usually find a few killdeer. These and such birds as the long-billed curlew, upland sandpipers, and sharp-tailed grouse break the near monotony of such prairie birds as western meadowlarks (Nebraska’s state bird), lark buntings, horned larks, and chestnut-collared longspurs. Lark buntings line the utility wires, taking off to sing their territorial songs, and descending with butterfly-like motions.

Hawks are here—red-tails, Swainson’s, ferruginous, marsh, and the little American kestrel—but in small numbers. We search long rows of fence posts for a burrowing owl and occasionally see one. Great-horned owls frequent tall cottonwood trees around the Agate ranch buildings. This is also the country of turkey vultures, golden eagles, and prairie falcons, but we have not been lucky enough to see them yet.

Mammals are more elusive. Cattle pasture conspicuously on land formerly claimed by the buffalo (bison). We see pronghorns each year. A lone coyote is the only other relatively large mammal we have logged. Check a good mammal book and you will appreciate what lives here largely invisible to the untrained eye: shrews, moles, bats, cottontails and two kinds of jackrabbits, pocket gophers, prairie dogs, kangaroo rats, voles, several kinds of mice, two kinds of ground squirrel, muskrats, beaver, raccoons, minks, badgers, longtailed weasels, two kinds of skunks, occasional porcupines and bobcats, white-tailed deer, and mule deer. Consider yourself lucky if you see the swift fox, mountain lion, and the rare black-footed ferret.

Life abounds here in other forms less noticeable to eyes trained on the Breeding Bird Survey: various species of amphibians, reptiles, fish, and the numerous insects associated with grasslands. We hear perhaps too much about rattlesnakes—western Nebraska has only the prairie rattler, whose numbers are now much reduced. Other snakes include western hognosed, blue racer, bullsnake, and the plains, wandering, and red-sided garter snakes.

Collections of Agate Springs Fossils

Museums You Can Visit

Many museums throughout the world have displays of fossils from the Agate Fossil Beds. Very few of them actually collected their own material. Museum curators are dedicated “horse traders” and fossil-swapping is part of the business. When museums such as the Carnegie Museum of Pittsburgh or the American Museum of Natural History in New York make collections like the ones made at Agate earlier in this century, they usually have some trading stock left over after completing their study collections and exhibits. They then can trade an extra Menoceras slab, for example, for a dinosaur skeleton from some faraway corner of the Earth.

At several museums in this country you can see mounted skeletons of several animals found at Agate, along with Menoceras slabs (sections of rock with the bones still imbedded) or models and dioramas of Agate specimens. To the right are listed, in order of proximity to the park, some of the museums and their specimens from Agate.

The United States Museum of Natural History, Smithsonian Institution, has many fossils that depict the life of the most recent 65 million years and several murals by artist Jay H. Matternes showing the life of each of the epochs. The Miocene mural, reproduced on pages 20-21 of this handbook, is among these reconstructions. It depicts ancient life around what is today known as Agate Fossil Beds National Monument.

The Trailside Museum Fort Robinson, Nebraska 69339. Menoceras slab, skeleton, and restoration Stenomylus skeleton on a slab, and a prepared limb Palaeocastor in a Daemonelix Palaeocastor in a plaster cast Museum of Geology, South Dakota School of Mines and Technology Rapid City, South Dakota 57701. Menoceras slab, beautifully prepared The Geological Museum University of Wyoming, Laramie, Wyoming 82070. Menoceras, mounted skeleton Stenomylus slab containing most of a skeleton University of Nebraska State Museum 101 Morrill Hall, 14th and U Streets, Lincoln, Nebraska 68508. Moropus, mounted skeleton Palaeocastor skeleton in a Daemonelix; also, two other Daemonelix Menoceras slab Dinohyus skeleton Stenomylus, a group of skeletons Field Museum of Natural History Roosevelt Road at Lake Shore Drive, Chicago, Illinois 60605. Menoceras slab Moropus skeleton The University of Michigan Exhibit Museum 1109 Geddes Rd., Ann Arbor, Michigan 48104. Menoceras slab and mounted skeleton Dinohyus eating dead Menoceras, a diorama Stenomylus skeleton and model Carnegie Museum 4400 Forbes Ave., Pittsburgh, Pennsylvania 15213. Promerycochoerus slab Menoceras slab and mounted skeleton Moropus, mounted skeleton Dinohyus, mounted skeleton Stenomylus, three skeletons mounted in a group The American Museum of Natural History Central Park West and 79th St., New York, New York 10024. Moropus skeleton Menoceras slab and skulls, one used in a sequence showing collecting and preparation techniques Dinohyus skull Stenomylus, nine skeletons and a reconstruction of the group in life Museum of Comparative Zoology Harvard University, Oxford Street, Cambridge, Massachusetts 02138. Menoceras slab Dinohyus skeleton Stenomylus skeleton

NPS Areas With Fossil Exhibits

Several fossil sites in the United States are under the protection of the National Park Service. Besides Agate, the major ones are:

Badlands National Park, South Dakota

Prominent deposits from the Oligocene Epoch, predecessor to the Miocene, combine with a rugged, eroded landscape and abundant wildlife to make Badlands a park where the natural processes of the past combine with those of today. The National Park Service maintains a Fossil Exhibit Trail at Badlands and presents fossil cleaning demonstrations. Prominent fossils are those of ancient camels, giant pigs, sabertooth cats, Protoceras, and Brontotheres. Mailing address: P.O. Box 6, Interior, SD 57750.

Dinosaur National Monument, Colorado and Utah

The late Jurassic muds and sands of the Morrison Formation have been a major source of dinosaur bones for more than a century. Steeply tilted strata near Vernal, Utah, were the source of tons of bones for the Carnegie Museum of Pittsburgh. This quarry site became the nucleus of Dinosaur National Monument. The bone-bearing stratum has been exposed by careful excavation, so that bones and partial skeletons of numerous dinosaurs are exposed in high relief. The entire quarry face is covered by a glass-walled structure that forms a large gallery. Mailing address: 4545 E. Hwy. 40, Dinosaur, CO 81610.

Florissant Fossil Beds National Monument, Colorado

This site has long been famous for its fossils of insects and plants preserved in fine-grained sediments. Specimens of Brontothere indicate an Eocene age for the deposits. Mailing address: P.O. Box 185, Florissant, CO 80816.

Fossil Butte National Monument, Wyoming

Within the strata of this rock remnant of an ancient lake is one of the most extensive concentrations of fossilized freshwater fish known to science. The site is about 18 kilometers (11 miles) west of Kemmerer, Wyoming. Mailing address: P.O. Box 592, Kemmerer, WY 83101.