Earlier this month, the Mendocino Land Trust got a one and a half million dollar grant from the state Wildlife Conservation Board to restore the butterfly’s habitat by removing invasive species and planting native pollinators, in tandem with experts from a wide range of organizations. At the same time, the sparse wild population of Behrens silverspots will be augmented by the ones raised in Damiani’s lab at the zoo. The difference between captive rearing and captive breeding is that in breeding programs, humans play a role in trying to encourage captive males and females to produce offspring. “Captive rearing is when we catch wild butterflies we hope have already mated in the wild,” Damiani specified. “Then we bring them back to the zoo and we hatch the eggs and we rear the caterpillars to the chrysalis stage and release the chrysalides back into the wild….It took a year of practicing captive rearing on a non-endangered species. Then it took another year to get our permit to do the captive rearing. We’re only starting our third year of raising the endangered species.” For the first year, she set a low bar, by catching seven butterflies and only planning to release twice as many into the wild. But “In our first year, we ended up releasing 72 butterflies, which we were pretty happy with,” she reported. Last year, the team released 245 butterflies.
She says they aren’t just beautiful. Unlike what might be the most iconic butterfly species, the Behrens silverspot stays at home year round, historically in a limited coastal range in Mendocino and Sonoma counties. “Especially in this area, monarchs aren’t really part of this community,” she noted. “They pass through, to feed on nectar, but they’re mainly on their way to their wintering grounds, or their breeding grounds. Whereas there are a lot of lesser known butterflies that maybe aren’t as showy as the monarch. They are the ones that are part of this community. They’re the ones who pollinate the flowers here, and they’re the ones whose caterpillars feed the wildlife here.”
Before they can be eaten, the caterpillars need something to eat, themselves. And their diet is limited, according to Anna Bride, a stewardship project manager at the Mendocino Land Trust. “The Behrens silverspot butterfly’s larval host plant is the early blue violet,” she noted. “They’re very hard to see.” She categorizes the violet as a “belly flower,” because it is so small, you have to get on your belly to see it. SHe said that, “Historically, these violets existed in very dense patches along the coastal prairie, but current climate change and disturbances have caused them to drop drastically in numbers, and also be out-competed by invasive grasses on our coastal prairies, so they’re getting harder to find, and that means they’re also harder to find for the butterfly.”
Over the next four years, Land Trust volunteers and members of the California Conservation Corps expect to plant 35,000 violets. An additional five to seven thousand other native pollinator plants will feed the adult butterflies and other insects throughout the season.
Asa Spade, a senior biologist with Wynn Coastal Planning and Biology, caught at least half the wild female butterflies for the captive rearing project. While he has an eye for tiny bugs, he takes a big picture view of conservation. “It’s not just the insects, it’s the native plants that they really need to feed on,” he emphasized. “Beyond that, it’s the soils and habitat. Much of the area that used to be Behrens silverspot habitat has been disced and plowed a hundred or more years ago. Those are the places where the non-native common velvet grass and sweet vernal grass really have a hold. They have a different type of root system than the native bunch grasses that the early blue violet grows among…the megafauna inspire people to vote to spend money protecting them, but it goes all the way down to the soils and the native plants.”
The vast majority of government money for recovery plans for endangered species is spent on salmon and steelhead trout, according to a report by CBS News. Spotted owls, grizzlies, and marine mammals are other beneficiaries, while plants and invertebrates often receive short shrift. But Damiani believes the Behrens silverspot butterfly has found its way into people’s imaginations.
Whenever she mentions that “I rear butterflies for a living, I get such a strong response that the butterfly means something very important to people,” she reflected. “It’s a symbol of transformation and new beginnings. A lot of people have told me that they really connect with butterflies.”
