How This California Man Repopulated A Rare Butterfly Species From His Backyard

When Tim Wong, a San Francisco native, decided he wanted to help repopulate the rare California pipevine swallowtail butterfly, he had no idea that he’d be leading the charge on what would become a massive conservation effort. Wong, who is an aquatic biologist, spends much of his time engaging with a number of strange animals (albino alligators, anyone?), never thought his interest in butterflies would result in a massive boost for the California pipevine swallowtail population in the Bay Area.

So how did he make it happen? Well, it all started with a cutting of the equally rare California pipevine plant – which is, inconveniently, the swallowtail’s sole source of food. Wong transplanted it into his yard at home and then, with no training whatsoever, began to build a large screened-in butterfly paradise. The enclosure allowed the butterflies to live under normal outdoor environmental conditions but protected them from predators, increased mating opportunities and served as “a study environment” to better understand the insects.

Once the enclosure was set up, Wong was able to source nearly 20 caterpillars from private residences (with permission, of course). From there, the caterpillars began the lengthy process of becoming butterflies. After about 3 or 4 weeks, the caterpillar forms a chrysalis. Inside this temporary home, it then develops into a butterfly in about two weeks…or stays dormant for up to two years. The adult butterfly typically hatches in the spring but it can be seen from February to October. Depending on temperature, food and a number of other factors, the butterflies live for two to five weeks. During that time, the female butterflies lay their eggs which Wong carefully collects and incubates indoors.

As the cycle of life continues, Wong raises the caterpillars at home and then brings them to the San Francisco Botanical Garden’s “California Native” exhibit. At first, he’d only bring a few hundred caterpillars at a time. But now, given the incredible success of his backyard efforts he is able to introduce thousands of caterpillars to the garden a year.

Wong is the only person who has successfully reintroduced the butterflies to the Bay Area. There have been previous attempts, but all the butterflies died out within a few years.

“Each year since 2012, we’ve seen more butterflies surviving in the garden, flying around, laying eggs, successfully pupating, and emerge the following year,” he said in an interview with Vox. “That’s a good sign that our efforts are working!”