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.