When aquatic biologist Tim Wong found out that the California Pipevine Swallowtail population was in decline, he recreated a safe habitat where they were able to flourish.
The California Pipevine Swallowtail butterflies used to flutter about San Francisco aplenty, but their populations declined in the 20th century as more areas were developed. Now in the early 21st century, they’re incredibly rare in the city, so one resident decided to do something. California Academy of Sciences aquatic biologist Tim Wong built a butterfly home in his own backyard, and around three years later is seeing the colorful blue butterflies slowly return.
Described as “the butterfly whisperer,” Wong spends his free time working to bring back the butterflies. He discovered when the California Pipevine Swallowtail is a caterpillar, it only eats the California pipevine plant. But those plants were also rare in San Francisco. Wong finally found the plant at the San Francisco Botanical Gardens, and they let him take some clippings home. 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 in an “ideal host plant.”
|Tim Wong’s backyard butterfly enclosure includes the California pipevine plant, along with other native flora, to make the butterflies feel at home.|
Wong started out with 20 caterpillars. Now around three years later, his butterfly home is thriving. He raises the caterpillars and then takes them to the San Francisco Botanical Gardens, and last year brought “thousands” to the botanical gardens. He’s now grown over 200 California pipevine plants. Wong told Vox, “We’ve seen more butterflies surviving in the garden, flying around, laying eggs, successfully pupating, and emerge the following year. That’s a good sign that our efforts are working!”
|Various stage of pipevine swallowtail growth (from bottom - eggs, different growth stages of the caterpillar, chrysalis, full butterfly).|
While you may not be able to build a butterfly home in your backyard, there are still actions you can take to help butterflies. Wong said, “Improving habitat for native fauna is something anyone can do. Conservation and stewardship can start in your very own backyard.” You can plant native plants and weed to allow butterflies to obtain food easier, and you can also stop using pesticides.
So what about the California Pipevine plant?
California pipevine (Aristolochia californica) ranges from about Monterey County north to the northern edge of the Sacramento Valley. Typically found near watercourses, pipevine usually grows where it can push roots into rich river-bottom soil. A semi-woody vine up to 12 feet or more in length, it climbs surrounding vegetation whenever possible, but will readily grow flat on the ground if no suitable vegetation is available for it to ascend.
In January, the vines begin greening up, and by February the first blossoms appear. They are about 1 inch long, green with brown-purple lengthwise veins, and remind me of old-time water pitchers, complete with a spout and deep "belly." The heart-shaped leaves, which begin to appear as the plant is blooming, can attain a length of more than 5 inches, while the fruit, 1- to 2Â½-long capsules, six-valved and six angled, form through the summer, splitting along prominent lengthwise sutures and releasing numerous seeds just before fall. The entire plant ? stems, blooms, leaves and capsules ? is covered with a soft, fine pubescence.
Wherever California pipevine grows will also be found Pipevine Swallowtail butterflies (Battus philenor). Black with iridescent blue hindwings, they are the earliest swallowtails to take wing and the latest seen at summer's end. The host plant for these lovely creatures is, as their name implies, pipevine.
|Tim Wong handful of late-growth-stage caterpillars.|
The butterflies' larvae, black caterpillars sporting quivering orange appendages and having voracious appetites, feed on the leaves and fruit capsules of the plants, which contain aristolochic acid, a lethal toxin that is supposed to deter browsing. The immune larvae absorb this chemical, rendering them, and later the butterflies they turn into, distasteful to potential predators.
As of yet, I haven't pushed my nose into a pipevine blossom to check, but experts maintain that in some species of Aristolochia, the flowers give off a disagreeable odor attractive to tiny carrion-feeding insects that, upon entering the bloom, become lost in its hairy interior. Some eventually find their way out, always covered with the flower's pollen. Attracted to another flower, they again become lost. Wandering about in this bloom, they spread the pollen from the previous plant, and fertilization is achieved.
|For most people, it’s the dream butterfly to work with in the region. It’s gorgeous. If most people saw it in SF, they wouldn’t think it’s a native butterfly. —Tim Wong|