Friday, July 8, 2016

Butterfly Conservation

Nice article at Vox about Tim Wong, a biologist who in his spare time is helping to bring the California pipevine swallowtail back to San Francisco, where it was increasingly rare.
He researched the butterfly and learned that when in caterpillar form, it only feeds on one plant: the California pipevine (Aristolochia californica), an equivalently rare flora in the city.

"Finally, I was able to find this plant in the San Francisco Botanical Garden [in Golden Gate Park]," Wong says. "And they allowed me to take a few clippings of the plant."

Then in his own backyard, using self-taught techniques, he created a butterfly paradise.

"[I built] a large screen enclosure to protect the butterflies and to allow them to mate under outdoor environmental conditions — natural sun, airflow, temp fluctuations," he says.

"The specialized enclosure protects the butterflies from some predators, increases mating opportunities, and serves as a study environment to better understand the criteria female butterflies are looking for in their ideal host plant."
My own butterfly conservation efforts, alas, are not such a success. I read somewhere that the best thing anyone could do to help monarch butterflies is to plant milkweed in your garden. So when a milkweed plant randomly sprouted under my kids' swingset, I transplanted it to the flower garden. There is has thrived and multiplied and become one of my worst weeds. And though I occasionally see a monarch in the garden, usually late in the summer, none have ever laid eggs.

Every summer my garden is completely overrrun with swallowtails, sometimes a dozen at a time. Thinking it would be fun for me kids to see the caterpillars, I planted some fennel, which is one of the plants they like. In my old garden I planted fennel and it ended up mostly eaten by caterpillars. But in my new house, the flocks of swallowtails find my fennel completely uninteresting – not a single egg, not a single boldly striped caterpillar. Sigh.

1 comment:

G. Verloren said...

Your butterflies may be suffering from either predation of some kind, or environmental poisoning. Both can be very hard to identify.