There was a time, not too long ago, when if you wanted to see a cougar or a bear, you'd have to go out into the wilderness. Now, in more and more parts of the country, you might not have to leave your back yard to find a predator big enough to eat you for dinner.
Animals that a few decades ago were considered nearly extinct in most of the United States have responded so well to the protections put in place that now even people in suburban areas of some parts of the country have had run-ins with brown bears and cougars.
At the same time, more and more people have been moving to parts of the country that were formerly wild, essentially moving into predators' neighborhoods. Even more than that, some naturalists say, people create environments that attract not only herbivores like squirrels and deer and small predators like fox and coyote, but big predators as well.
"We have set up an environment that encourages these predators to come into our communities," said David Baron, the author of "Beast in the Garden," which uses the fatal mountain lion attack on a jogger in Boulder, Colo., to examine the interaction between humans and predators.
"Bears prefer to live in the city because life is so much easier," Baron said. "They become fatter and lazier, because there's so much food and they get so many more calories. It's the same with the mountain lions and the deer. We've created these lush communities that draw deer, and that draws mountain lions."
What exacerbates the situation, according to some people, is that having been protected for so many years, these big predators have lost their fear of humans. They do not see people as "alpha predators" they need to fear. Once humans reassert themselves by hunting these animals, the argument goes, the beasts will leave the garden and leave humans alone.
Some biologists suggest there is a basis for this belief.
"If deer or elk are hunted, they become very shy," said David Klein, a professor of biology at the University of Alaska. "When they're not, they don't see humans as threats. It's the same with bears."
Animal protection groups and some naturalists, however, dispute this idea.
"If you hunt a bear and you kill it, that bear hasn't learned anything," Baron said, but he said he believes "hunting has a role" in keeping animals out of the suburbs.
"Hunting is part of the answer, but it's not the only answer," he said.
David Quammen, the other of "Monster of God: The Man-Eating Predator in the Jungles of History and the Mind," suggests that approach might even have a negative effect, because it would take "the biggest and boldest cats out of the gene pool, and those that are left are less afraid of humans."
"If every time a cougar sees a human, that cougar is dead, then cougars overall aren't learning anything," he said.
Others say that humans, thinking they are helping the animals, have actually helped to create the problem by putting out food for wild animals.
"The number one reason that wild animals have lost their fear of humans is people feeding them," said Nina Fascione, vice president for field conservation programs at Defenders of Wildlife. "If people are going to be stupid, we're going to have problems. Wildlife should have a healthy fear of humans, and there are certainly nonlethal ways to intimidate these animals."
What is certain is that there is a growing amount of contact between humans and big predators, and this is leading lawmakers in some states to reconsider the protections that were put in place to ensure that animals like bears and cougars would not be wiped out.
In New Jersey, controversy has raged for years about what to do about the black bears that roam the nation's most densely populated state. The dispute has pitted those who feel the solution is to continue the hunt that was allowed in 2003 but banned in 2004, and others who believe the answer is some combination of relocation, birth control and sterilization.
This spring a pony was attacked and killed in Sussex County, apparently by a black bear that was likely hungry after its winter hibernation.
"No other animal would have the strength to do that kind of harm. It would take a lot of strength," state Department of Environmental Protection Fish and Game Division spokeswoman Elaine Makatura said.
On the other side of the country, Oregon lawmakers have been debating whether to rewrite an 11-year-old law that banned using dogs to hunt cougars, except in cases where a particular animal had been identified as a threat.
There have been increasingly frequent sightings reported in the Northwest, some by parents of small children who have seen cougars lurking in places where kids are around.
In Vancouver, Wash., across the Columbia River from Portland, two cougars roamed into a residential neighborhood recently, in yet another sign of how the lines are blurring between what might be considered humans' turf and wilderness where animals rule.
"You can bury your head in the sand and lose a child, but do we want to err on the side of that policy? I don't think so," said Oregon State Rep. Jeff Kropf, a Republican from Albany, one of the lawmakers who want to reverse Measure 18, the voter-approved measure that outlawed the use of dogs, except when cougars are an identified threat.
Animal protection groups have argued that talk about changing the law is fearmongering, and an overreaction.
"Not yet has one cougar attack happened in the state of Oregon, but the bottom line is that laws are already in place to deal with any problem cougars," said Kelley Peterson of the Humane Society of the United States. "[There are] a handful of trophy hunters who think these practices are OK, but the voters clearly say it's inhumane."
Animal rights groups say bee stings and dog bites are already more of a threat by far than cougars and that enacting new regulations would be costly to a state that is still in financial trouble.
"Tell that to a parent who may lose a child out of a back yard to a young male cat who's very hungry," Kropf said.
According to several attempts to count mountain lion attacks through searches of media reports, the number of attacks on humans has generally increased throughout North America as the population has recovered over the last 20 years, but it appears that in no year were there more than nine attacks.
The attacks have occurred all across the western half of the continent, though, from Arkansas to Alaska, and there have been at least 13 fatal attacks since 1988.
Cougars are particularly well-adapted to living close to humans because they are solitary nocturnal hunters and they do not need a large range, unlike wolves or grizzly bears, Quammen said.
In Alaska, hunters will be allowed to use bait when they go after grizzly bears in a 3,000-square-mile area near the Canadian border, but not because of problems with humans. The practice will be allowed for the first time since Alaska gained statehood because grizzlies are being blamed for the decimation of the moose population in parts of the interior of the state.
In some areas where bears and people have been rubbing shoulders too much, authorities have been trying some novel approaches to separate the two.
In addition to trying to teach humans how not to encourage bears to dig into their garbage cans for food, police and game officials in some towns in California, Colorado, New Mexico and other states in the West have been armed with guns that shoot beanbags, horns that blast loud noises and other devices to annoy bears found roaming too close to town.
"The first time bears come into a residential area, before they've gotten addicted to human food and don't associate humans with food, it works fairly well," Klein said. "Once they've gotten addicted to human food, it won't work anymore."
In New Jersey, there is a $100 fine for feeding bears, and in Colorado you can be fined for even inadvertently feeding bears, for example, if your garbage is left out in containers that bears can open.
Of all the big predators, though, it is probably the gray wolf that has raised the most opposition, even though it would seem that it poses the least direct threat to humans. According to wolf biologists with the U.S. Fish and Wildlife Service, there are no recorded fatal attacks on humans by a healthy wolf in North America.
But wolves have a taste for livestock.
"Livestock people generally detest, loathe and fear them, and sometimes with good reason," Quammen said.
Wolf populations in Montana, Idaho and Wyoming have reached levels where Fish and Wildlife is ready to de-list them and turn management over to the states, but that plan has been held up over a dispute between Wyoming and the federal government over the state's proposed management plan.
Wyoming's plan, backed by ranchers concerned about their herds, would allow wolves to be shot on sight in most of the state.
But the return of the wolf to the Northern Rockies has provided a valuable lesson for biologists, because of the wide-ranging effects on the environment they have seen there. The effects were not limited to the wolf's prey, but extended to vegetation and even erosion patterns, and none of it was expected.
"If we didn't know about it for wolves, one of the most closely studied species, I don't even want to say what we don't know for the effects of other species," Fascione said. "You want to play it safe, because once a species is gone, it's gone."
The dispute over the wolf is emblematic of the whole problem, though, because, scientists say, people on both sides of the argument do not really see the animal clearly, either taken in by its charisma or seeing it as evil because of its skill as a predator of sheep and cattle.
"Our big problem is we don't understand adequately the complexity of nature, how animals and humans can all fit into the system," Klein said. "We have the potential, we have the knowledge -- if we use it -- to create a beautiful environment, but people have to be educated."
ABC News affiliate KATU-TV in Portland, Ore., contributed to this report.