Seeing Butterflies

In hindsight, mid-July was maybe not the best time to go in search of butterflies on Strawberry Hill. Butterflies are drawn to heights to seek mates, making the hilltop a destination for about 13 different types, as a sign posted there explains. But butterflies also like heat, sun, low winds – in short, the very opposite of the microclimate enveloping the hill the day I visited it with one of the city’s top lepidopterists, Liam O’Brien.  

Once a successful actor, O’Brien quit the stage to turn “his incredible talent for observation and theater into a career as San Francisco’s foremost butterfly champion,” as Bay Nature magazine put it. In addition to conservation work, he’s known for his meticulous drawings and paintings of butterflies. His pictures are both exacting and fun. (A bit like O’Brien himself, who titled his blog about butterflies “The Flying Pansy.”) He’s illustrated books, articles, maps, and signs around the city, including the one on Strawberry Hill and has a book on Bay area butterflies due out next year from Heyday Books.

Even though we were guaranteed not to see a single butterfly in flight, O’Brien had plenty else to show me and share from his vast stockpile of butterfly lore. (One of the best tidbits I learned that day: the technical term for an adult butterfly is an “imago;” plural, “imagines.” That’s wonderful enough in itself, but “imago” can also mean the idealized image of someone who’s been influential, such as a parent.) 

Nearing the summit — is that too grand a word for something only 400-feet high?— we stopped by the reservoir that feeds Huntington Falls. “This is why I wanted to bring you here,” he said, leaning over the short fence and peering into a tangle of blackberry brambles and weeds. He pointed out a trailing vine with heart-shaped leaves: “Aristolochia californica, Dutchman’s Pipe vine. This is the only host plant for the California Pipevine Swallowtail.” It’s the only plant on which the butterfly will lay its eggs. Some butterflies are generalists, happy to drop their eggs in many places. But not the Pipevine Swallowtail and that singular connection to the plant is a problem for the species, because, the Dutchman’s Pipe is “very rare in San Francisco.”

Looking closer, he cried out, “Oh my God, we lucked out. There’s a Swallowtail caterpillar. They’re one of my favorite caterpillars. Because of how they look, I always thought they should have their own Japanese horror film.” He directed my eyes to a large black caterpillar with rows of orange-red spikes along its body inching along a leaf.

There were about a dozen in all clinging to the vines. “We are so lucky,” he said again. “I’ve never seen them on here.” His enthusiasm was contagious. I’d never even heard of the animal  until that moment, but now I too felt incredibly lucky to see it. 

After feasting on the leaves for a few weeks, these very hungry caterpillars would encase themselves in chryslases. In time they would emerge wholly transformed – no longer squishy, earth-bound creepy-crawlers, but delicate airborne jewels with blue-black wings spotted in pale white and orange. We admire butterflies for their ethereal beauty, but I think what we really love is that act of metamorphosis; their enviable magical trick.

Photo by John Flannery

At the top of the hill, O’Brien showed me the various flowering plants that have been placed there by volunteers (like him) and Rec and Park gardeners to attract and support butterflies. The purple spires of Budleja davidiii favored by the big Swallowtails. The pink and purple-blossomed radish plant, where cabbage whites lay their eggs. Red-and-white Scrofularia, a host for the variable checkerspot. The pom-poms of coast buckwheat that play host to a trio of butterflies with names that sound like off-brand super-heroes: the Green Hairstreak, the Grey Hairstreak and the Acmon Blue.

We stopped at his sign, still looking new after 15 years. He pointed out a favorite quote he’d included on it from Vladimir Nabokov, another passionate lepidopterist: “It’s astonishing to me how few people notice butterflies.”  Certainly, I was one of those non-observant people Nabokov was talking about. But then again, so was O’Brien during the first stage of his life. 

He’d gone into theater while young, quickly succeeded, and made his way onto Broadway playing the gangster Montparnasse in “Les Miserables” for three years. In 1998, he moved back to California to be understudy to the lead in “Angels in America.” Later, he took over the role. One day, a black-and-yellow Western Swallowtail flew into his backyard. “I was drawn to go down and look at it. It was on a Cosmos, I remember.” He had the urge to paint it and ran back inside to get paper and paints. Something was changing inside him. Within a week he’d sold off his Thomas Hardy novels to buy a field guide to butterflies. By the end of the month, he’d joined the local lepidopterist society. “And I was off and running.”

And yet…to love butterflies is to be all too attuned to their precarity. San Francisco is home, after all, to the first North American butterfly known to be extinguished by human activity. The Xerces blue’s habitat was the coastal sand dunes, but as the growing city swallowed the dunes, the butterfly became scarce. As early as 1875, a local entomologist was predicting its demise. 

“The last one was collected in 1946 in behind the old hospital in Lobos dunes in the Presidio,” O’Brien said. Even now, when he goes to national lepidopterist meetings and people learn where he’s from “you can literally see a pall come over most lepidopterists’ faces…The Xerxes story kind of hangs over [us] like a cloud.”  

O’Brien has been working to prevent that fate for other Bay area species, such as the Green Hairstreak, a gorgeously iridescent butterfly about the size of nickel.

It once ranged from downtown out to Ocean Beach, but was thought to have disappeared from the city due to loss of habitat. Around 2005, O’Brien discovered small isolated populations of the butterfly on two hills in Golden Gate Heights and the Presidio Bluffs. He knew isolation leads to inbreeding which leads to the end of a species. He mapped the species’ historic and existing habitats then teamed up with the non-profit Nature in the City, to create the Green Hairstreak Corridor, a stretch of butterfly gardens in backyards, school gardens and slivers of public land along 14th Avenue. That ribbon of habitat makes it possible for the once-separated populations to meet, mingle, and mate. It’s restoring the species.

O’Brien is now involved in a similar project on behalf of the Tiger Swallowtail, “the butterfly that started it all for me.” The Tigers on Market project will plant living roofs on new BART exits along the length of Market Street, so the butterfly has a long uninterrupted flyway in which to seek nectar. 

To O’Brien, such efforts are as much for humans as they are for butterflies: “Robert Michael Pyle, who's sort of the godfather of American butterflying says, it's not just the creature going extinct. It's the extinction of experiencing the creature. That too goes extinct.”

A few weeks after my walk with O’Brien, the sun finally came back out and I went back to Strawberry Hill. On a clear day, the hilltop affords a long view. You can see out to the ocean and to the Golden Gate bridge. But this time I shortened my focus onto the plants right in front of me. Two pale cabbage whites appeared. I watched them dip and spiral around each other in what I guess was a mating dance. Then they fluttered over the bushes and out of sight.