Saving Gorgeous Butterflies, One Egg at a Time

Tim Wong really, really loves animals. The biologist spends his weekdays caring for, and studying, sea creatures at the California Academy of Sciences, while his days off are spent hand-rearing thousands of butterflies in his backyard. Currently, Wong is working to restore San Francisco’s pipevine swallowtail butterflies.

With a velvety blue body and wings like swatches of night sky, the California pipevine swallowtail (Battus philenor hirsuta) is a breathtaking sight indeed. But that sight has become more and more rare in San Francisco as the butterflies’ preferred food (Aristolochia californica, the California pipevine) disappears from the city. 

Piece by piece, Wong is bringing it back. When the long-time lover of lepidoptera learned of the butterflies’ plight, he vowed to do whatever he could to keep them going. 

The first step was finding something for the bugs to eat. Given the pipevine’s growing scarcity, this was, unsurprisingly, something of a challenge. Wong eventually spotted a specimen growing in a botanic garden in Golden Gate Park and got permission to take a clipping.

Next, using a lifetime of accumulated knowledge about butterflies, Wong constructed a custom corral that could provide the swallowtails with their accustomed climate and conditions while keeping them safe from predators. The enclosure’s design also encourages the butterflies to mate and allows Wong to unobtrusively study the goings-on within.

When the enclosure was finished, Wong collected 20 swallowtail caterpillars from local residences and placed them gently upon the pipevine inside. He watched, transfixed, as the hungry caterpillars munched their way en masse from plant to plant, like guests at a progressive dinner party. Eventually, they were satiated and settled down to begin the long, strange process of metamorphosis. 

The resulting butterflies were luminous and healthy. Before too long, they had laid their bright red eggs, which Wong painstakingly collected and incubated indoors, away from egg-gobbling spiders and earwigs. When the eggs hatched, Wong ferried the newborn caterpillars back to their ancestral homeland in Golden Gate Park. Each year he reintroduces more caterpillars; last year, he says, there were thousands. But there’s more to it than just dropping off the kids. By reinvigorating the park’s pipevine growth, Wong has also ensured that they have something to eat.

While an intensive and thoroughly researched DIY species conservation program may be a bit more than most people can manage, Wong told Vox, anyone can pitch in and make a difference. "Conservation and stewardship can start in your very own backyard."  

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