Second Year of Sierra Nevada Blue Surveys

A male Sierra Nevada blue kindly sitting on my finger for a portrait at Bradley Lake

Last year, Joe Doerr, Willamette National Forest (WNF) wildlife biologist organized several trips to the Calapooyas to survey a lovely little butterfly known variously as Sierra Nevada or gray blue (Agriades or Plebejus podarce), which is at the northern end of its range in the Calapooyas (see More Butterfly Surveying in the Calapooyas). This year, we returned to many of the same areas we visited last year to see how they were doing. Our first trip was July 11. Joe and I were joined by John Koenig, Lori Humphreys, and Joanne Lowden, Middle Fork District wildlife biologist.

Bradley Lake is one of the prettiest subalpine wetlands I know of in the Western Cascades.

We started the day at Bradley Lake, where we had seen dozens of Sierra Nevada blues last year. It was gorgeous there. Unlike the dried-out, low-elevation milkweed sites I’d been frequenting of late, the wetland flowers around the lake were fresh and the foliage lush. It was still pretty early in the season at over 5000′, and there was even a little snow along one edge, and we had passed roadside ditches with remaining snow banks. The great camas (Camassia leichtlinii) was especially beautiful. We saw lots of butterflies, but we didn’t see as many Sierra Nevada blues as we had hoped. Still they were there, and that was a good sign. It seemed like most were fresh males, and I wondered if maybe males and females came out at slightly different times.

Lori, John, Joanne, and Joe searching for the blues among the great camas.

Great arctics aren’t all that common and seem generally shy about being photographed. I can only guess that this one was either newly hatched or still cold from the morning temperatures. It walked right onto my finger when I offered it a ride.

After lunch, we surveyed the wetlands on the east side of Loletta Lakes. This is the site we started at last year when it was still quite cool in the morning. While we did find some of our blues, the afternoon warmth didn’t stir up more as I’d hoped. We did see an American lady, a species I don’t think I’ve seen before—or at least I didn’t recognize if I had seen it. Lori helped explain the differences between it and the similar and more common painted lady and the West Coast lady. I’ve noticed the slight differences in wing shapes, but there are also small differences in coloration and spots. It can be hard to remember all these little differences among similar species, so I either take a photo so I can look it up later or go out with an expert like Lori! We were very relieved (and surprised) that there didn’t seem to be any mosquito problem this year. Of course, not long after I said this aloud, we into a barrage of mosquitoes in a dry meadow on our way to a hidden wetland. Very odd that they were only in that spot, but I was thankful for that. 

Note the white dot in the orange on the forewing of this American lady. Its wing is squared off at the end, with a noticeable indent in the middle. The painted lady lacks the dot and has longer forewings without a conspicuous indent.

Dragonflies were plentiful at the quarry wetland. This one is seated on elephant’s head.

With enough time left for one more site, we went over to the wetland by the old quarry to the north of Loletta Lakes. John and I had spent a lovely late afternoon there last August and thought it showed promise as a Sierra Nevada blue site, but it was too late in the season for us to look for the blues. It had plenty of both their host food plant, mountain shooting star (Dodecatheon jeffreyi), and their favorite nectar plant, bistort (Bistorta bistortoides). At the time, the wetland was covered with thousands of the snow white blossoms of grass-of-Parnassus (Parnassia cirrata var. intermedia). They were just beginning to bud up on this trip. The flowers were farther along than at Bradley Lake, with good stands of Elephant’s head (Pedicularis groenlandica), among other things. Again we saw a great many butterflies, including Hoffman’s checkerspots, greenish blues, painted ladies, Mylitta crescents, northwestern fritillaries, and lilac-bordered coppers—but no Sierra Nevada blues at all. Being so close to the other wetlands, and with the same plant species, I’m not sure why they hadn’t found this wetland. Maybe a few of them will stumble upon it in time, although since we never once saw a Sierra Nevada blue even a few yards from a wetland, we have no idea how they ever move across dry land to discover a new home.

One of the most common butterflies of the day was Hoffman’s checkerspot, this one nectaring on arrowleaf groundsel (Senecio triangularis).

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