Tim Wong of San Francisco works as an aquatic biologist during the day, but over the past four years he has spent his free time on another scientific mission: repopulating San Francisco’s rare California Pipevine Swallowtail butterfly population.

Wong learned that the California Pipevine Swallowtail caterpillar, only eats the California pipevine plant, hence the name of the species. However, those plants were rare in San Francisco, and local populations of the butterfly have been steadily declining.

Wong was able to obtain plant clippings from the San Francisco Botanical Gardens, from there, Wong built a large screen enclosure that would allow the butterflies to mate in natural conditions and allow him to observe precisely what they needed.
Wong gathered a group of 20 different pipevine swallowtail caterpillars from nearby areas. As he carefully nursed the small tribe of insects, their numbers began to quickly multiply.

Now years later, the butterfly breeder brings dozens of caterpillars to the San Francisco Botanical Garden’s “California Native” exhibit every week — and thanks to Wong’s efforts, the pipevine swallowtail has been successfully repopulated in the city for the first time in decades.