BOB ABERNETHY, anchor: There's an issue in Iowa and other parts of the Midwest that raises the question: What should humans do about endangered but also dangerous animals? Kill them, capture them, or leave them alone? What if you saw, or thought you saw, a cougar -- also known as a mountain lion -- in your backyard? Lucky Severson went looking for cougars early this past spring.

LUCKY SEVERSON: This is Iowa: 55,000 square miles of soybeans and cornfields. Before the farms, the landscape was wild prairie. Cougars prowled the high grass.

That was way back when -- back when settlers like Alice Walsh were first farming Iowa's rich soil in the mid-1800s. But now it seems the cougars are back: a few tracks in the river bottoms, an unlikely picture.

Several cougars have been killed -- a cold welcome after an absence of almost 140 years. More are out there haunting farmers and terrifying mothers and raising the question, Can man and beast survive together in today's world? Does man have an ethical duty to protect the beasts among us, even when they're dangerous? Would we be the less if they disappeared?

Listen to Ron Andrews.

RON ANDREWS (Biologist, Iowa Department of Natural Resources): It would be a crying shame on earth when we lose an animal, and particularly an animal that's been abundant in Iowa. I just hope it doesn't happen.

SEVERSON: Of course, this may be only hypothetical because many of the reports are simply hearsay. The only place you're certain to see a real cougar in Iowa is a zoo, or Rick Braaksma's farmyard.

He keeps Harley and Cheyenne in a makeshift cage that was built to hold corncobs.

RICK BRAAKSMA (Farmyard Owner): There's been a lot of people out to look at them.

SEVERSON: But it's not pet cougars in corncribs that are attracting so much attention in Iowa; it's wild cougars on the loose in the countryside.

UNIDENTIFIED WOMAN (At Town Meeting): About 10 days ago, about, I saw two together early in the morning about 8:30 -- going in just, like, just complete rhythm.

SEVERSON: Over the past 18 months, there have been 21 documented cougar sightings in nine Midwestern states, including Iowa -- places cougars aren't supposed to be and aren't welcome.

Iowa has the least amount of public lands of any state in the country, hardly anything you would call wilderness. There's a farm on nearly every horizon. So why are mountain lions immigrating here?

Wildlife experts say the reappearance of mountain lions out on the flatlands can be traced to mankind and mismanagement. There's no longer enough room in the mountain West for the expanding cougar population, so they're moving eastward.

James Mahaffy is a professor of zoology who maintains a Web site that tracks Iowa cougars.

Dr. JAMES MAHAFFY (Biology Professor, Dordt College, Sioux Center, IA): Because of the biology of the cougars, males have to -- when they wean from Mom -- have to leave the territory, or Dad will kill them.

SEVERSON: There's been no official poll, but most Iowans seem to agree with Gary and Jason Klaiber and their hunting dogs about having cougars in their backyard.