The Oregon silverspot butterfly is beautiful and rare.
Unfortunately, this beauty and rarity is under threat due to habitat degradation. And while the danger is real, there is a plan to deal with it led by the US Fish and Wildlife Service and its partners.
The butterfly, federally listed as threatened since 1980, is found only in four locations worldwide: north of Lake Earl, California, and in the Siuslaw National Forest, Mount Hebo and Cascade Heads. Additionally, the butterfly will be found at Saddle Mountain where it will be reintroduced for the first time this spring/early summer and at Nestucca Bay National Wildlife Refuge, where it will be introduced this summer after having been extinct since the 1970s.
Currently, the Arcata Service and Newport Fish and Wildlife offices are working with a variety of partners to include several zoos, universities, nonprofits, local parks, and the U.S. Forest Service in an attempt to save the species in hopes. to possibly remove it from the list of endangered species.
A passionate partner is the Tolowa Dunes Stewards – a group of citizens of Crescent City and the surrounding area, dedicated to the restoration and conservation of the Tolowa coast and the education of these lands.
On April 14, 2018, the Tolowa Dunes Stewards along with the Service and other partners participated in the 5th Annual Scotch Broom Bash at Earl’s Lake Wildlife Preserve. The event centered on the removal of the Scotch broom, an invasive species that has negatively altered the habitat around the butterfly’s food source (in the form of caterpillars) – the leaves of Viola adunca or Western Dog Violet; early blue violet.
A total of 14 volunteers cleaned up a half acre of habitat, which filled a 40 cubic yard dumpster. The Service also incorporated a study into the Bash to examine purple densities before and after Scotch removal over the next few years, to quantify the purple response.
“I love this Scotch Broom Bash because it’s such a joy to see restoration and recovery coming to the North Shore of Earl’s Lake – finally,” said Sandra E. Jerabek, stewards of the Tolowa Dunes. “The Pacific Shores Subdivision has been home to hundreds of silverspots and other animals over time. This recovery is proof of the incredible resilience of Indigenous life – if we can just help it like we did last Saturday (April 14).
“We have also visited areas along the subdivision roads where we have removed Scotch broom and they are now full of ponds with happy frogs and other life. »
Clint Pogue, a biologist from the Arcata office of the US Fish and Wildlife Service, who helped organize the event, also felt a sense of accomplishment.
“In recent years, we’ve been able to remove dense stands of Scotch broom and open up areas of butterfly and violet habitat,” said Pogue, who leads the Silverspot project for the Arcata office. “We are reducing the areas we can access. »
The Service and its partners have annual monitoring stations spread throughout the habitat area with the aim of obtaining weekly butterfly counts beginning in early July for 10 weeks. Another goal is to acquire land and create a contiguous area of ownership by agencies such as the California Department of Fish and Wildlife and California State Parks.
“As public agencies acquire more plots, there will be additional areas that can be treated,” Pogue said. “I think it is possible that it will be removed from the endangered species list. I think there is a lot of potential. »
The partners’ efforts also include the work of local zoos, such as Woodland Park and Oregon Zoos, which breed silver caterpillars in captivity before releasing them. The hope is that the caterpillars pupate, emerge as adult moths and reproduce in the wild.
Another attempt is in progress with Nestucca Bay and the Institute of Applied Ecology working with Coffee Creek Women’s Correctional Facility to grow violets. Violets typically grow in coastal grassland areas kept open by ocean disturbance. Salt spray is important to maintain the constant changes needed to allow the violet to thrive in a less competitive environment.
“Natural coastal grassland communities can be enhanced for the Oregon silverspot butterfly by planting violets in these areas,” Pogue said. “One thing people can do is if they have a piece of land that they don’t use for farming or if they have an interest in converting farming back to something natural, they can plant native nectar sources that will flower and provide nectar beginning in early July. in mid-September.
A major concern for Pogue is that coastal grassland systems are extremely rare because they overlook the ocean, are easy to grow, cultivate, and turn into anything but coastal grassland.
“We are losing habitat for the species and have lost many due to development along the coast,” Pogue said. “We are also experiencing shrub and conifer encroachment into these coastal grasslands due to disturbances that do not occur, such as elk grazing or lack of fires. »
Over the past three years, Pogue says the Service has seen a decline in California’s population. “It’s unmanaged – hundreds of miles from the nearest population that we know of, so that may be a signal that we need to take more drastic action to manage it,” he said. Only seven silverspots were counted during surveys in 2017, compared to an average of 440 over the previous 11 years.
Arcata’s office is currently in discussions with the Newport Fish and Wildlife Office about possibly augmenting the Californian population at Earl’s Lake using captive-bred caterpillars and pupae, similar to previous efforts in Oregon.
“People can help by leaving an area in their yard with native plants,” said Anne Walker, biologist at the Newport office. “If we can get 10 populations with 200-500 butterflies for 10 years, we can delist the species. »
Butterflies can be a sensitive species due to a multitude of factors,” Pogue said. “The potential effects of chemicals on the landscape can be detrimental and the sensitivity of butterflies to these habitat changes can serve as an early indicator of the degradation of the integrity of our natural communities which provide excellent places to recreate, see nature as well as ecosystem services for humans.
“It can also serve as an important warning signal that things are getting worse – the population decline of this butterfly could be the product of natural community degradation. We need to pay attention to this and seek to understand what is happening in these cool coastal prairie communities.
Partners include: California Coastal Commission’s Whale Tail License Plate Grant Program, Oregon Zoo, Sequoia Park Zoo, Woodland Park Zoo, Oregon Parks and Recreation , Siuslaw National Forest, Lewis and Clark National Historical Park, Del Norte Solid Waste Management Authority, Hambro WSG , Recology Del Norte, Institute for Applied Ecology, The Nature Conservancy, Oregon State University, Pacific University , University of Washington, Washington State University – Vancouver, Tolowa Dunes Stewards and California Department of Fish and Wildlife.