SAN FRANCISCO (CBS SF) – Tim Wong is an aquatic biologist at the California Academy of Sciences, but his real passion lies nearly hidden on the academy’s living roof in San Francisco’s Golden Gate Park.

Nestled among plants growing on the roof is the pipevine – a native plant all but wiped out by the growth of San Francisco.

Without the pipevine sprouting around the city, the California Pipevine Swallowtail butterfly has also almost disappeared.

Wong is on a mission to bring the butterfly population back.

“Native butterflies were kind of always a part of my life growing up,” he said. “It (the California Pipevine Swallowtail) is just such a beautiful, iridescent blue, tropical looking butterfly.”

So the man nicknamed the ‘Butterfly Whisperer’ began planting pipevine in the garden and watching to see if the butterflies would return.

“She’s (a female California Pipevine Swallowtail) looking for the perfect spot to lay her eggs,” said Wong during a recent visit to the rooftop garden. ”They’re actually very picky.”

Wong claims his passion has helped him create a bond with the butterflies.

“I can kind of think like a butterfly, and I almost know what they’re looking for,” he said.

What butterflies are looking for is the right habitat and that’s becoming increasingly difficult as urban centers expand.

Bill Toone works for an organization called Ecolife. The group is working to protect the habitat of the Monarch butterfly in Mexico.

“The single greatest cause of extinction (of a butterfly species) is the loss of habitat,” he said.

“Butterflies are important because they’re a pollinator, and pollinators account for one out of every three bites of food we take,” he said. “Without them, we will die.”

Toone’s group is encouraging local municipalities and individuals in California to re-plant native species in their yards and gardens.

Retired San Francisco firefighter Mike Belcher has done just that.

“It’s kind of like ranching, you know, you raise cattle you grow alfalfa, so I grow plants for butterflies,” he said.

Some 17 years ago, he began planting pipeline hoping to help in rejuvenating the local California Pipevine Swallowtail population.

“I planted it here 17 years ago with the hope that maybe someday the Pipevine Swallowtail would find it and breed here,” he said. “The line I use is If you plant it, they will come.”

And this year, thanks to Wong’s efforts, the rare butterfly has come back.

“Oh it’s fantastic to have them back,” Belcher said.