Butterflies are often among the most endangered of insects. Some of their caterpillars can only survive on select host plants, so if their habitats are destroyed and the host plants disappear, the butterflies disappear as well.
Of the 65 species of butterfly native to northwest Oregon, 15 are now rare or missing entirely. (“Extirpated” is the term for when a species no longer exists within a certain region.) Here I wanted to share some of those rare species and their imperiled ecosystems.
Butterflies of the Willamette Valley
The prairies of the Willamette Valley are one of Oregon’s most imperiled ecosystems. Over 99% of the native grassland has been destroyed for development and agriculture. In Columbia County stretches of native prairie used to be found from Scappoose to Deer Island, of which tiny remnants in the St. Helens area are all that are left. As a result of this loss, many special Willamette Valley butterflies cannot be found here.
Fender’s Blue (Icaricia icarioides fenderi) Found in Willamette Valley prairie from Portland to Eugene, where it feeds solely on Kincaid’s Lupine. Has been reduced to the limited plots of native grassland where this plant still grows. Listed as a federally Endangered Species. (photo © Jeff Ward)
Great Copper (Lycaena xanthoides) – A wetland prairie species that requires Willow Dock and Willamette Valley Gumweed to survive. Restricted to California and western Oregon, it had not been seen in the Willamette Valley in over 30 years until a population was discovered in wetlands near Eugene. (photo © Bart Jones)
Mardon Skipper (Polites mardon) Found in open grassland, feeding on native grasses such as Roemer’s Fescue. Now missing from the Willamette Valley due to loss of upland prairie habitat. The last populations of the species are found in a few small prairies south of Olympia and around Ashland and Crescent City. (photo © Tom Kogut, USFWS)
Field Crescent (Phyciodes pulchella pulchella) Found in native meadows throughout the western USA where it feeds on various asters. May now be gone from the northern Willamette Valley including Columbia County due to loss of habitat. (photo © cschelz7)
Taylor’s Checkerspot (Euphydryas editha taylori) – An Endangered Species on the brink of extinction, with only 2 remaining populations in Oregon (near Salem and Eugene) and a dozen more in Washington and British Columbia. Requires native prairie habitat where it feeds on figworts and plantain. (photo © Steve Ansell)
Monarch (Danaus plexippus) – Due to pesticides, climate change, and habitat destruction, Monarch populations worldwide have decreased by over 90% since the 1990s, leading to its placement on the IUCN Red List as Endangered. Monarch larva feed solely on milkweed, which grows in native prairies. (photo © Nicolas Sly)
Butterflies of mountain meadows
Due to the suppression of natural fire and use of herbicides in clearcuts, many native mountain meadow wildflowers are no longer present in the northern Coast Range. As the wildflowers disappear, so do the butterflies who depend on them.
Snowberry Checkerspot (Euphydryas colon) – Found in mountain meadows, where it feeds on snowberry and figwort. May now be gone from Columbia County due to management issues in forestry that limit native vegetation. (photo © Jim Johnson)
Callippe Fritillary (Speyeria callippe elaine) – Also called “Elaine’s Fritillary”, this species was once found in the Coast Range but is now extirpated west of the Willamette Valley. Requires mountain meadows, feeding on Nuttall’s Violet, Evergreen Violet, and other related species. (photo © Ken Kertell)
Valley Silverspot (Speyeria zerene bremnerii) – A native of inland grassland and mountain meadows, it survives in a few tenuous locales in Washington and British Columbia but is extinct in Oregon. Feeds on Nuttall’s Violet, which can be pushed out by invasive vegetation. (photo © Michael Ferguson)
Oregon Silverspot (Speyeria zerene hippolyta) – Restricted to coastal salt-spray meadows, which have disappeared due to coastal development and intrusions on the succession cycle. A Federally Threatened Species, only five populations remain, of which three are in northwest Oregon. (photo © USFWS – Pacific Region)
Coastal Green Hairstreak (Callophrys dumetorum) – A rarely seen species that in Oregon has only been found to feed on two species of deervetch, a type of herb that grow in disturbed openings in mixed mountain forest. No remaining populations are known in Columbia County. (photo © Stefan)
Greenish Blue (Icaricia saepiolus) Extinct or extremely rare west of the Cascades. Feeds on Long-stalked Clover and Springbank Clover, which grow in damp mountain meadows and open slopes, especially near streams. (photo © Liam O’Brian)
Butterflies of woodland and forest
The Willamette Valley ecoregion included oak forest alongside its upland prairies, but most were cut down to make way for roads, homes, industry, and farmland. Our remaining oaks continue to be cut down to this day. Coniferous forest is still extensive, but logging has eliminated old-growth forest in Columbia County, and thus insects reliant on the oldest trees are no longer welcome here.
Johnson’s Hairstreak (Callophrys johnsoni) – Feeds on dwarf mistletoe, a parasitic plant that grows in mature Douglas Fir and is restricted to older forests that have not been disturbed by large-scale logging or herbicide. Considered a sensitive species due to habitat loss. (photo © Ken Kertell)
California Sister (Adelpha californica) – Feeds on the leaves of oak trees, thus is rare in the northern Willamette Valley due to the lack of oak woodlands in our region. (photo © amandajb35)
Tailed Copper (Tharsalea arota) – Feeds on several species of gooseberries, which grow in riparian woodland. Has become rare in our region of Oregon, only recently rediscovered in Polk and Benton counties after over 70 years of no sightings in the Willamette Valley. (photo © Noah Strycker)
Some of these rare species are similar to more common species that can still be found in the county. If you are interested in figuring out what kinds of butterflies you have in your area, check out our identification page. You can also get ID’s by taking pictures of the butterfly and uploading them to www.iNaturalist.org.
4 thoughts on “Rare and extirpated butterflies of Northwest Oregon”
I live in the Nehalem valley (Mist area) … are there native plants I can plant to help the endangered butterflies in Columbia county? I’m not mountainous, but I want to help!!
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Great question! It’s always difficult to know whether planting certain plants will bring butterflies, because they rely on multiple aspects of the natural environment besides just the food plants alone, so some of the rare butterflies need their entire native ecosystem restored, not just one plant. And I’m not sure if the plants will thrive with their particular needs, depending on your property. But just in case you wanted to try, here are some of the essential food plants of rare butterflies that might be found in your area:
Common Snowberry (for the Snowberry Checkerspot)
Big Deervetch (for the Coastal Green Hairstreak, Gray Hairstreak, Silvery Blue, and Silver-spotted Skipper)
Nevada Bird’s-foot Trefoil (for the Coastal Green Hairstreak, Persius Duskywing)
Long-stalked Clover and Springbank Clover (for the Greenish Blue)
If you want to know more about planting for butterflies, then I would contact Chip Bubl at the OSU Extension Office for Columbia County and he should be able to put you in touch with the right person. I think the Columbia County Master Gardeners program has several associates who are interested in planting for insects (https://extension.oregonstate.edu/mg/columbia).
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Sad, it happens the world over.
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