After our successful day finding Sierra Nevada blues at Bristow Prairie (see Searching for Butterflies at Bristow Prairie), Joe Doerr, Willamette National Forest (WNF) wildlife biologist, was hot to see if we could find more populations of the rare butterfly within the WNF. Other surveyors had been looking for them on the Umpqua National Forest in the past couple of years, but after I spotted them at Loletta Lakes last year (see NARGS Campout Day 2: Loletta Lakes), just inside the WNF, it seemed likely there might be more spots nearby. The boundary of the Forests is the crest of the Calapooyas, so while the northern Bristow Prairie site is in Lane County, both populations there are just west of the crest, putting them over on the Umpqua National Forest side. So far, this area is the northern end of their limited range, which reaches south to the Sierra Nevada in California.
Joe planned a trip up to the Loletta Lakes area on Tuesday, July 5, and I was thrilled to go up to one of my favorite places and get driven up the long gravel Coal Creek Road by Joe along with Cheron Ferland, another wildlife with the WNF. We planned to meet Erin and Dominic, two biologists from the Umpqua National Forest, up near Loletta Lakes. Joe had mapped out where all the wetlands are on the north (WNF) side of the crest, hoping to check out as many as we had time for. We met Erin and Dominic on the east side of Loletta Lakes where I always park when I go up to Loletta Peak or visit the wetland where I spotted the Sierra Nevada blues last year. If you read the report on my trip to Pyramid Rock last year (see A Day Full of Surprises), you might recognize this as the spot where I had to change a flat tire last year—one of the reasons I was so happy not to be driving my own van up here! We decided the wetland was too shady at this time of day, and as it was still early (these guys get up much earlier than I do!), it was rather chilly—not prime time for butterflies. The wetlands on the west side of the lakes were sunnier, so we started there.
The flowers looked promising: plenty of bistort (Bistorta bistortoides)—apparently their favorite nectar plant—coming into bloom and lots of mountain shooting star (Dodecatheon jeffreyi), their host food plant, in fading bloom. Very little seemed to be out and about, just a few meadow fritillaries. I was impressed that Joe managed to scare up the first Sierra Nevada blue fairly quickly while walking around. Eventually everyone found some at this new site—a great start to the day! We were also looking for another rare insect, the western bumble bee (Bombus occidentalis), a large bee notable for white markings on end of its abdomen. Joe had finally found one the day before up at Waldo Lake, the first one seen in the area for many years, as the once common bee has apparently been in a steep decline. We saw a surprising number of honeybees as well as other bumblebees, but unfortunately no one ever found a western.
From there we walked north through a narrow band of woods to a somewhat drier meadow. There was a lot of blooming long-stalked clover (Trifolium longipes), a host food plant for greenish blues, and those were indeed what was flying around in this area. But as we crossed over into another, much wetter area and back into bistort and shooting star habitat, we started seeing Sierra Nevada blues again. It seemed that the day was warming up and the butterflies were becoming much more active.Now it was time to go back and check the eastern wetland. It was much sunnier at this point, but we had to walk a ways north before we spotted the first Sierra Nevada blue, just a bit farther than the one I photographed last year. But once we found the first one, they seemed to be common, moreso than any other species there, in fact. Our day was going really well!
Erin and Dominic had to head back to Glide, but Joe, Cheron, and I decided to keep searching. There had been a large tree across the road when Joe came up to look for good habitat a couple of weeks before, but since someone had recently removed the tree, we were able to get to Bradley Lake, three miles east of Loletta Lakes, a spot I had thought would be worth checking but one we hadn’t expected we’d be able to get to. When we got to the area above the lake, we also considered going farther up Road 5851 to another more easily accessed roadside wetland. That idea was quickly quashed by another downed tree, so down to Bradley Lake we went.
And what good luck that turned out to be. Not only were the flowers and setting gorgeous, but we spotted the Sierra Nevada blues within a minute of reaching the wetland. And they were everywhere! We didn’t even have to look for them flying. They were perched on bistort all over the place. They were also very cooperative, letting me hold the flowers they were on so they wouldn’t wave in the wind. Joe was keeping track of what we saw all day, but he gave up after a while here. He had stated on the way up in the morning that he hoped to find 100 of our target blues. I thought that was overly optimistic, but there really were dozens at Bradley Lake, and it is possible that had we gone back to the other sites in the warmth of the afternoon, there might have been even more there as well. I don’t yet know what the official count was, but we were quite pleased to find so many.
Clearly the Sierra Nevada blues are well established in this part of the Calapooyas. Now we need to find out if they have spread farther north. And are they spreading north as a result of global warming, or have they always been here and we never noticed? I’d also be really interested to know more about their life cycle, including how they overwinter (literature says caterpillars or chrysalids) and how long they survive as adults. Most of the males we saw were very fresh. Some of the females looked more worn. Do they hatch slightly earlier? We finally saw some courting pairs at the edge of Bradley Lake but didn’t actually see any mating. Maybe in a week or so we might find them laying eggs of the shooting stars.
It’s easy to tell males from females if you can see the dorsal (upper) sides. Like most if not all blues, the males are blue on top and the females brown. After looking and photographing so many males and females, I started to notice they looked different on their ventral (under) sides as well. Comparing the photos at home, it seems clear to me that the females are a much warmer brown on their ventral side, while the males are a grayish brown. I didn’t see this mentioned in any of my books or on the major butterfly websites, so I don’t know if others haven’t noticed this or if it’s not true for the species of over its whole range, but I did find some photos on the internet that showed females as brown as ours. So much still to learn about these pretty butterflies—I can’t wait to go back and keep looking!
Butterflies observed in Loletta Lakes and Bradley Lake area
- Sierra Nevada blues (Agriades [Plebejus] podarce)
- Greenish blues (Plebejus saepiolus)
- Boisduval’s blues (Plebejus icarioides)
- Western-tailed blue (Cupido amyntula)
- Echo azures (Celastrina echo)
- Meadow (Pacific) fritillaries (Boloria epithore)
- Hoffman’s checkerspots (Chlosyne hoffmanni)
- Edith’s or snowberry checkerspots (Euphydryas editha or E. colon)
- Great arctic (Oeneis nevadensis)
- Clodius parnassians (Parnassius clodius)
- Pale swallowtails (Papilio eurymedon)
- Western tiger swallowtail (Papilio rutulus)
- Orange sulphur (Colias eurytheme)
- Sara orangetip (Anthocharis sara)