Miriam Mcdougall has a theory about bears.

It has something to do with what might be referred to as the rise of man.

Our story begins in 1933, when Miriam was born on a 45-acre spread near Dewdney. It was what she called a "stump ranch," farmland so raw it still had uncleared stumps on it.

"We grew up right against a mountain," Miriam said, "and I mean right at the end of our backyard there was the foot of a mountain."

It was hard, forested land, but the odd thing about it, Miriam said, was there were never any bears around. She never saw a one.

"You just didn't see them," she said. "And this was in the days of the galvanized garbage can, when the garbage men would slam it down after emptying it and the lid would never fit right again. But there were never any bears scavenging in our garbage."

Fast-forward a couple decades. Miriam moved to West Vancouver in 1955. She now lives on shorefront property on Bellevue Avenue -- "17 minutes from downtown Vancouver," she said -- which, separated as it is from the mountains by a freeway and several residential neighbourhoods, is unlikely bear habitat even for the North Shore. Despite this, it has become unbearable.

"I have bears eating my raspberries," Miriam said. "I have bears eating grapes off my vines on my upper deck, three storeys up. I have bears peeking in my windows. I have bears rubbing up against the doorknob of my back door so they can scratch their butts. I see bears all the time."

It was not always so in West Vancouver, she said:

The bears began showing up only 10 years ago.

The usual theories for an increase in bear encounters in communities like those on the North Shore cite loss of habitat, climate change affecting natural food supplies and increases in scavenging opportunities in suburban neighbourhoods.

Also, North America has seen a dramatic increase in the black bear population. Estimates range from 600,000 to more than 800,000 black bears continentwide, while B.C.'s population is estimated at between 120,000 and 160,000, a historic high.

Miriam doesn't buy any of it. She puts it down to one thing:

"I think Viagra has given us the bears," Miriam said.

She believes the rise in incidence of bear sightings on the North Shore and the, um, rise of Viagra in 1998-99 is a coincidence too hard to ignore. The link between the two, Miriam believes, is the bear's gall bladder, that organ that was traditionally used in Asian medicine as an aphrodisiac. Viagra, the efficacy of which has been proven, has made traditional (and suspect) remedies like bear gall bladder obsolete. Thus, Miriam believes, the gall bladder market has crashed while the bear population has increased.

"A friend of mine knew 15 people who made a living poaching bears. That's why I didn't see any bears growing up. They were being hunted. Now, none of [the former poachers] hunt."

This is a theory, or hoped-for result, that has been made before. When Viagra was first introduced, some conservationists hoped it would take the pressure off of endangered species being hunted for their supposed medicinal properties.

Quantifying that, however, was impossible. In the mid-1990s, conservationists estimated that poachers were killing as many as 40,000 black bears annually in B.C. They warned that the decrease of bear populations in Asia due to poaching there had increased poaching pressures here. And there are still media reports that bear poaching is alive and well, especially in Russia, where bear populations are stable. But as for poaching numbers here in B.C. since the introduction of Viagra, the provincial environment ministry's official reply was:

"We do not have poaching numbers. Clearly, it would be very difficult to accurately establish what these numbers look like given that many poaching incidents go unreported."

As for any possible correlation between Viagra and the rise in bear numbers, the ministry's answer was even more terse. It read:

"We will not be commenting on this."

Prof. Alan Cassels, with the University of Victoria's health information science department, and an expert on Viagra, said he had never come across anything like Miriam's theory in his studies. His exact quote was:

"No. Never. Ever." And then for emphasis, he added:

"Ever."

As a last resort, I phoned Mike Allen, a black bear researcher who runs bear viewing tours for Whistler/ Blackcomb. He may know more about black bears than anybody in B.C. Allen is of the opinion that the cold spring and high winter snowpack has forced the bears to lower elevations this year, while years of scavenging human garbage in areas like the North Shore have imprinted bears to keep doing it.

When I asked him of a possible connection between Viagra and bear populations, there was a momentary silence on the line, and then he said:

"That is the last question I thought you'd ask me."