Baskett Slough: Fender's Blue a rare and wonderful sight

Road Journals Blog—I had just moved to Salem when I first heard tales of the Fender’s Blue. My neighbor told me about swarms of tiny blue butterflies blanketing a nearby sun-swathed hill for just one or two weeks at the end of May and beginning of June. He said it was not to be missed.

If you, too, have an enthusiastic neighbor, you know that stories like these can be worth checking out.

Fender's Blue at Baskett Slough. | George Gentry/USFWS Pacific

The Fender’s Blue was collected in this region as early as the 1920s, but has long thought to be extinct. Then in 1989, conservationist Paul Hammond took notice of some unidentified blue-grey butterflies that were thriving in patches of Willamette Valley prairie grasses, primarily at the Baskett Slough National Wildlife Refuge.

(The refuge protects 550 acres of native grasslands, 300 acres of forests, 500 acres of shallow-water seasonal wetlands, and 35 acres of permanent open water, mostly for visiting waterfowl and Canada geese. And now, butterflies.)

Fender's Blue on its lunch of choice. | George Gentry/USFWS Pacific

What conservationists have since learned: Fender’s Blue rely on Kincaid’s Lupine, a dainty pink, threatened prairie flower. The butterflies lay their eggs at the base of these flowers, and the larvae eat the leaves of the plant during the autumn. They then crawl down its base to hide for the winter.

Come spring they build their cocoons and prepare for the great reveal in early May and June. The Kincaid’s Lupine, and only the Kincaid’s Lupine, it must be.

If it’s a sunny day and you’ve timed it right, you might be at Baskett Slough on the day when the butterflies emerge from their cocoons. I tried it myself on a bright day last spring. I’m a sucker for ephemera, and butterflies are the kings of this category.

I trekked up the refuge’s main hill, on a path that cuts through prairie grasses and ends up at a stunning 360-degree overlook, with a bird’s eye view of the Willamette Valley between Salem and the Cascades.

When I turned around, I saw them.

Or, rather, it.

There was only one little Fender’s Blue Butterfly, flitting around and chasing the breeze, moving in quick switchbacks, alighting briefly upon a dainty pink flower and rarely slowing down enough for me to study him closely. (I say “him” with confidence, as females have rust-colored wings.)

Yes, I came late to the party. But it was, without question, worth it.

Emily Grosvenor wrote about the Fender's Blue in the May/June 2011 issue of VIA.

This blog post was first published in May 2011. Some facts may have aged gracelessly. Please call ahead to verify information.