For the past year and a half, a fierce battle has raged over whether three African elephants should stay in their decades-old home at the Toronto Zoo.

But it's a battle that some experts say is now at the centre of a larger North American debate about the future of elephants in zoos.

Since the facility opened in 1974, the Toronto Zoo has always had elephants.

Deciding to stop housing the showstopping animals that bring so many visitors through its front gates is no easy decision —and one that's put it at the centre of a larger North American debate about the future of elephants in zoos.

In an interview with CBC's the fifth estate, internationally renowned zoo director and architect David Hancocks thinks that zoos are "on the cusp of a major paradigm shift."

While people have wondered for years whether a zoo can exist without the presence of an elephant, Hancocks suggests a different future. "I suspect as soon as 10 years time we'll probably hear people say, 'How can you call yourself a zoo if you've got an elephant in it?'"

80 acres vs. two

The Toronto Zoo saga began in May, 2011, when the board recommended an end to its elephant program, and that its three remaining female pachyderms — Toka, Thika and Iringa — be moved due to costs and other factors.

David Hancocks, former director of the Seattle Zoo, says the embattled Association of Zoos and Aquariums is trying to protect its turf. (CBC)

PAWS Sanctuary in northern California fit all the zoo's requirements for a potential new home, including that it accept elephants past breeding age (all three Toronto elephants are in their 30s and 40s) and not use metal bull hooks for discipline.

The 2,300-acre sanctuary is home to 27 tigers, five lions, seven bears and eight elephants, all rescued or retired from zoos or circuses.

Elephants live with others of the same species and gender. Eighty acres alone are designated for female African elephants, such as the Toka, Thika and Iringa, compared to their enclosure in the Toronto Zoo of less than two acres, mostly concrete.

• CBC's the fifth estate: Join the live chat during Friday's show

"Our sanctuary has obviously more space and more diversity," said sanctuary executive director Ed Stewart.

But problems soon arose. Zoo officials complained the Galt, Calif.-based sanctuary wasn't accredited by the U.S.-based Association of Zoos and Aquariums (AZA).

AZA then weighed into the debate, arguing that "non-accredited zoos and private elephant facilities (so-called sanctuaries) are not an appropriate alternative" to an AZA-accredited facility, the only one that would provide the "highest level of care."

Hancocks, former director of the Seattle Zoo and an ex-AZA member, says the embattled association was trying to protect its turf.

"The AZA has gone out of its way to vilify the sanctuaries," said Hancocks. "They’ve told all sorts of wrong stories, they’ve put out wrong information and they criticize them very harshly. … They don’t want the public embarrassment of the public knowing the conditions in zoos are so bad that they have to go to a sanctuary."

Zoo group pulls accreditation

In the midst of AZA's lobbying campaign, almost six months after the original decision to move the elephants from the city-owned zoo, Toronto City Council added its voice to the mix, voting 31-4 to pass a motion to send Thika, Toka and Iringa to the PAWS Sanctuary.

AZA then urged the zoo to get city council to reverse its decision, warning in a letter that if not, "we cannot predict possible actions that might be taken."

The Edmonton Valley Zoo also dealt with questions over their lone elephant, Lucy. Officials there decided that moving posed a greater risk due to the elephant's respiratory issues. (CBC)

In the spring of 2012, the zoo association revoked the Toronto Zoo's accreditation.

Hancocks believes the decision is part of an AZA strategy to keep control of such headliner animals as elephants that the zoo concept is built around.

"What they’re doing in fact is sending a warning shot across the bow of every other city council in North America and [that] if you even think about removing your elephants to a sanctuary, we’re going to take your accreditation away," said Hancocks.

Zoos are big business. More people visit zoos every year in North America than attend professional sporting events. The Association of Zoos and Aquariums in North America estimates 175 million visitors go to zoos a year, creating billions of dollars in revenue.

Other zoos close elephant programs

The elephantine battle at the Toronto Zoo may be the longest and most heated, but it is not the only one being waged over whether zoos are inadequate for the massive creatures, particularly in colder climes.

The Alaska Zoo built their elephant, Maggie, a treadmill at a cost of $150,000. (Courtesy of John Gomes/Alaska Zoo)

Many of the world's best-known facilities have already retired their elephants or announced their intention to do so, including the London and Edinburgh zoos in Britain, Bronx Zoo in New York and the Lincoln Park Zoo in Chicago.

After four decades of housing elephants, earlier this year the Calgary Zoo decided to move its elephant herd to another facility within the next five years.

But in spite of rising anger this year over Edmonton Valley Zoo's lone elephant, Lucy, officials there have refused to budge. They say the Asian elephant has a respiratory disease that makes a move potentially fatal.

Five years ago, the Alaska Zoo was facing similar opposition over Maggie, a South African elephant who arrived at the zoo in 1983 as a baby. Patrick Lampi, director of Alaska Zoo, acknowledges that Anchorage is not an ideal elephant habitat.

"For us in Anchorage, it was the cold weather, number one, and the length of the winter," he said. "So there was a good six months of the year where she got to go out very little — just on exceptionally warm days when there wasn’t any wind and the snow conditions were right."

But despite the cold weather, a growing Free Maggie movement and the fact that Maggie was deprived of crucial contact with other elephants, the zoo at first refused to send the animal away.

It consulted 10 recognized elephant experts. Nine out of 10 recommended that Maggie should be moved, but the zoo listened to the lone holdout: Dr. James Oosterhuis of San Diego, who recommended that Maggie could stay if the zoo changed her routine and made an estimated $300,000 in changes to her enclosure.

Costs ballooned to $1.2 million, nearly bankrupting the zoo. The enclosure's outdoor area was expanded, new heating, lighting and ventilation were installed and a six-metre-long, 7,000-kg treadmill was built for $150,000. But it sat unused by Maggie.

In late 2007, the zoo decided to send Maggie to the PAWS Sanctuary in northern California, moving the four-ton pachyderm 4,000 kilometres via a U.S. Air Force C-17 transport plane.

Future of zoos?

For TV legend and animal rights advocate Bob Barker, the key issue remained: "Maggie was all alone — no matter how well they're fed or how well they're housed, an elephant that's alone is miserable."

Former game show host Bob Barker questions the future of all zoos. (CBC)

The final straw came when Maggie fell twice and firefighters had to be called in to get her back on her feet.

After PAWS veterinarian Mel Richardson went to visit Maggie, he concluded: "After seeing that she’d already been down twice and we’re going into winter again, I felt she’s going to die. She’s going to die there. What have we got to lose by moving her?"

Maggie survived and thrived at the sanctuary.

Barker, who paid for Maggie's and other elephants' flights to the PAWS sanctuary, says that not only is the role of elephants in zoos in question, so is the nature of the zoo itself.

"There will be a time that people are going to say, 'Do you know that back there for years and in 2012 even, they had zoos they called them and they took these beautiful animals and they stuffed them in cages,'" Barker told CBC's the fifth estate. "'Can you picture that? In cages. Can you imagine that? It was the dark ages. Dark ages.' That’s what I predict."

Watch the fifth estate on Friday at 9 p.m. (9:30 in Newfoundland and Labrador) and join their live chat.