America’s Grasslands Once Teemed with Animals. We Must Save What’s Left of Their Vanishing Habitat

Joel Berger and Jon Beckmann February 20, 2020

Bighorn sheep graze on grassland in Yellowstone National Park, Wyoming.

In the grip of win­ter, the North Amer­i­can prairies can look decep­tive­ly bar­ren. But many wild ani­mals have evolved through harsh win­ters on these open grass­lands, for­ag­ing in the snow and shel­ter­ing in dens from cold tem­per­a­tures and bit­ing winds.

Today most of our nation’s prairies are cov­ered with the amber waves of grain that Katharine Lee Bates laud­ed in Amer­i­ca the Beau­ti­ful,” writ­ten in 1895. But sci­en­tists know sur­pris­ing­ly lit­tle about today’s rem­nant bio­di­ver­si­ty in the grass­lands – espe­cial­ly the sta­tus of what we call big small mam­mals,” such as bad­gers, fox­es, jackrab­bits and porcupines.

Land con­ser­va­tion in the heart­land has been under­whelm­ing. Accord­ing to most esti­mates, less than 4% of the tall­grass prairie ecosys­tem that once cov­ered some 170 mil­lion acres of North Amer­i­ca is left. And when native grass­lands are altered, pop­u­la­tions of endem­ic species like prairie dogs shrink dra­mat­i­cal­ly.

Togeth­er, we have more than 60 years of expe­ri­ence using field-based, hypoth­e­sis-dri­ven sci­ence to con­serve wildlife in grass­land sys­tems in North Amer­i­ca and across the globe. We have stud­ied and pro­tect­ed species rang­ing from prong­horn and bison in North Amer­i­ca to saiga and wild yak in Cen­tral Asia. If sci­en­tists can iden­ti­fy what has been lost and retained here in the U.S., farm­ers, ranch­ers and com­mu­ni­ties can make more informed choic­es about man­ag­ing their lands and the species that depend upon them.

This maps shows the major types of North Amer­i­can grass­lands. (Graph­ic coun­rtesy of Karen Launchbaugh/​Wikimedia Com­mons)

Two harsh cen­turies of settlement

North America’s prairies stretch north from Mex­i­co into Cana­da, and from the Mis­sis­sip­pi Riv­er west to the Rocky Moun­tains. Grass­lands also exist in areas far­ther west, between the Rock­ies and Pacif­ic coastal ranges.

When Thomas Jef­fer­son approved the Lewis and Clark Expe­di­tion in 1803, this ter­ri­to­ry was home to Native Amer­i­cans and abun­dant wildlife. Vast, unbro­ken hori­zons of con­tigu­ous grass­lands sup­port­ed mil­lions of prairie dogs, prong­horn, bison and elk, and thou­sands of bighorn sheep. Birds were also numer­ous, includ­ing greater prairie-chick­ens, mul­ti­ple types of grouse and more than 3 bil­lion pas­sen­ger pigeons.

Lewis and Clark kept detailed records of the plants and ani­mals they encoun­tered on their three-year jour­ney. Their jour­nals describe griz­zly bears and wolves, black-foot­ed fer­rets and bur­row­ing owls, sage grouse and prairie chick­ens. Sources like this and John James Audubon’s Birds of Amer­i­ca,” pub­lished between 1827 and 1838, con­firm that before Euro­pean set­tle­ment, North America’s prairies teemed with wildlife.

Prong­horn, which Lewis and Clark called Speed goats,’ graze on the prairie beneath Wyoming’s Wind Riv­er Range. (Pho­to by Joel Berg­er, CC BY-ND)

That changed as Euro­pean immi­grants moved west over the next hun­dred years. Mar­ket hunt­ing was one cause, but set­tlers also tilled and poi­soned, fer­til­ized and fenced the land, drained aquifers and dam­aged soils.

As humans altered the prairies, bison dis­ap­peared from 99% of their native range. Prairie dogs, black-foot­ed fer­rets, wolves and griz­zly bears fol­lowed the same sad course.

In the mid-20th cen­tu­ry, con­ser­va­tion­ists began fight­ing to pro­tect and restore what remained. It isn’t sur­pris­ing that wildlife agen­cies and con­ser­va­tion orga­ni­za­tions focused on tar­gets that were big, famous and eco­nom­i­cal­ly impor­tant: Birds for hunt­ing, deer for din­ner and fish­eries for food and sport.

Some efforts suc­ceed­ed. Mon­tana has retained every species that Lewis and Clark observed there. In 2016 Con­gress passed leg­is­la­tion declar­ing bison the U.S. nation­al mam­mal, fol­low­ing var­i­ous restora­tion ini­tia­tives in places such as the Wichi­ta Moun­tains of Okla­homa and the Tall­grass Prairie Pre­serve in the Flint Hills of Kansas. Prong­horn ante­lope, which Lewis and Clark called speed goats,” have rebound­ed from few­er than 20,000 in the ear­ly 20th cen­tu­ry to some 700,000 today, rang­ing across grass­lands from north­ern Mex­i­co and Texas to North Dako­ta, Mon­tana and south­ern Canada.

But elk remain rare on the grassy savan­nas, as do prairie dogs and wild bison. North Amer­i­can grass­land birds – larks and pip­its, curlews and moun­tain plovers – are in decline or seri­ous col­lapse. Intro­duc­tion of non­na­tive exot­ic fish, reduced water flows in prairie rivers and streams due to agri­cul­ture, and declines in water qual­i­ty and quan­ti­ty have dec­i­mat­ed native fish species and aquat­ic inver­te­brates, such as fresh­wa­ter mus­sels, in the water­ways of grass­land ecosystems.

Where the ani­mals still roam

In con­trast to North Amer­i­ca, oth­er regions still have large intact grass­lands with func­tion­al ecosys­tems. White-tailed gazelles and khu­lan (Asi­at­ic wild ass) still move hun­dreds of miles across the vast unfenced steppes of Mon­go­lia. White-eared kob, a sub-Saha­ran ante­lope, trav­el hun­dreds of miles every year across a North Dako­ta-sized swath of south­ern Sudan in one of Africa’s longest land migra­tions.

Chiru (ante­lope) and kiang (large wild ass­es) main­tain their his­tor­i­cal move­ments across the vast Tibetan plateau. Even war-torn Afghanistan has des­ig­nat­ed two nation­al parks to ensure that snow leop­ards, wolves and ibex can con­tin­ue to roam.

Some parts of the North Amer­i­can prairies could sup­port this kind of bio­di­ver­si­ty again. The Flint Hills of Kansas and Okla­homa, Nebraska’s Sand­hills and Montana’s Rocky Moun­tain Front all retain areas that have nev­er been plowed, rang­ing from 1 mil­lion to 4 mil­lion acres. Pub­lic agen­cies and non­prof­it con­ser­va­tion groups are already work­ing in these areas to pro­mote con­ser­va­tion and sup­port grass­land ecosystems.

Knowl­edge gaps impede conservation

Con­serv­ing native species on Amer­i­can grass­lands has moved slow­ly because this region has been so com­pro­mised by land con­ver­sion for farm­ing and devel­op­ment. What’s more, despite tech­no­log­i­cal inno­va­tions and pow­er­ful ana­lyt­i­cal tools, sci­en­tists don’t have real­is­tic esti­mates today of abun­dance or pop­u­la­tion trends for most ver­te­brate species, whether they are mam­mal, bird or fish.

This pho­to shows a white-tailed jackrab­bit in Wyoming. (Pho­to by Joel Berg­er, CC BY-ND)

Mea­sur­ing rem­nant diver­si­ty is a first step toward decid­ing what to pri­or­i­tize for pro­tec­tion. One way we’re doing this is by pos­ing sim­ple ques­tions to fam­i­lies who’ve lived out on these lands for mul­ti­ple gen­er­a­tions. One Mon­tana ranch­er told us the last por­cu­pine he saw was – well, he couldn’t remem­ber, but they used to occur. Anoth­er, in Wyoming, said it had been per­haps two decades since he had last seen white-tailed jackrab­bits, a species once com­mon there.

From Col­orado to New Mex­i­co and the Dako­tas to Utah, respons­es are sim­i­lar. Across the region, the sta­tus of species like fox­es, por­cu­pines, white-tailed jack rab­bits, beavers, bad­gers and mar­mots is punc­tu­at­ed by ques­tion marks. Con­ti­nent-wide trends remain a mystery.

The good news is that nation­al parks have inven­to­ry and mon­i­tor­ing pro­grams that make it pos­si­ble to assess trends more com­pre­hen­sive­ly for some of these species. Cit­i­zen sci­en­tists are help­ing by report­ing occur­rences of species such as black-tailed jackrab­bits. As sci­en­tists delve fur­ther into data­bas­es, pat­terns of species reten­tion or loss should become clearer.

For exam­ple, our work on white-tailed jack rab­bits revealed that decades ago they were abun­dant in the val­leys in and around the Tetons of north­west Wyoming and spanned Yel­low­stone Nation­al Park’s north­ern range. How­ev­er, by the year 2000 they were absent from the Tetons and occu­pied only a small area of Yellowstone.

The U.S. has a his­to­ry of pro­tect­ing its majes­tic moun­tains and deserts. But in our view, it has under­val­ued its bio­log­i­cal­ly rich grass­lands. With more sup­port for con­ser­va­tion on the prairies, wildlife of all sizes – big and small – could again thrive on America’s fruit­ed plains.

Edi­tor’s Note: This arti­cle is repub­lished from The Con­ver­sa­tion under a Cre­ative Com­mons license. Read the orig­i­nal arti­cle.

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