Aquarium Assists With Oregon Silverspot Butterfly Habitat Restoration

November 19, 2008

The threatened butterfly requires a specific coastal habitat to survive

Habitat restoration for the threatened Oregon silverspot butterfly received assistance from the Oregon Coast Aquarium early this month. The Aquarium grounds staff helped by rooting and planting nectar producing food sources for butterfly habitat. The Oregon silverspot butterfly (Speyeria zerene hippolyta), listed as a threatened species since 1980, requires a very specific coastal habitat and certain plants to survive. A collaborative effort between the U.S. Fish & Wildlife Service (USFWS), the Nature Conservancy and other agencies seeks to stabilize declining silverspot populations.

Brent Butler, Aquarium groundskeeper, had been doing volunteer work at the Nature Conservancy and suggested the Aquarium assist with the project. Val Knox, Nature Conservancy botanist, called Bob Llewellyn, Aquarium grounds manager, last summer and asked for help. “We were in dire need of nectar sources for the adults’ upcoming fall food, so we asked the Aquarium for some aster seedlings,” said Knox. “They not only agreed to give us the asters, but they also volunteered to plant them.”

Planting day arrived and the Aquarium grounds crew including Bob Llewellyn, Brent Butler and Bob Merry showed up with tools and plants. “I couldn’t believe how many they brought,” said Knox. “Through wind and rain, climbing steep slippery slopes; armed with planting tools and good natures, they arrived with the power of flowers!” Knox said they put 1,500 plants in the ground that day to help sustain the butterfly throughout its life cycle.

“The weather wasn't really so bad, it was fun,” said Llewellyn. “We brought asters and goldenrods. Anne Walker and Val Knox brought violets raised by the Natural Resource Conservation Service, Plant Materials Center in Corvallis. We planted all of these on a rainy windswept hillside overlooking the ocean south of Yachats.”

The Oregon silverspot is a brown and orange butterfly that lives in humid coastal salt-spray meadows and fields from northern California to Washington. Adult silverspots use their proboscis to sip nectar from asters, pearly everlasting, yarrow and goldenrod. The butterfly is a threatened species due to loss of habitat and the decline of its host plant, the violet. When their eggs hatch into caterpillars, they eat the only the leaves of the early blue violet (Viola adunca).

“Ideally, we’d like to restore silverspot habitat between Rock Creek and Bray Point,” said Anne Walker, USFWS Endangered Species biologist. “There are a number of steps people can take to help including participation in the Safe Harbor Agreement, which allows landowners to do habitat restoration on their property.” Other steps Walker cited include planting native species, removing invasive species, mowing on a high setting, not mowing around the edge, minimizing herbicide use and using extreme caution in preserve areas.

The Nature Conservancy, U.S. Fish and Wildlife Service, Lewis and Clark College, Oregon Zoo and Woodland Park Zoo are working together to implement a silverspot captive-rearing program. Adult female silverspots are collected and encouraged to lay eggs. The caterpillars that hatch are then raised at the college and the zoos, until they become pupae and are released into the declining populations.