07/19/2026
While on a photo expedition in Great Basin National Park, NV, earlier this month, I kept seeing butterflies far above the timberline near the peak of 11,658-foot Mount Washington. Here is a western tiger swallowtail and an Ethel's checkerspot. I encountered both within about 20 feet of the Mount Washington summit. So what are these butterflies doing in such an inhospitable, high-altitude place, aside from the fact that there were many small, low-growing alpine flowers dotting the rocky slopes? Likely, they were "hilltopping." From Wikipedia: "Male butterflies congregate at topographic summits. The most dominant males aggressively claim and defend the best perching spots at the very peak, aggressively chasing off competitors. They will remain on these hilltops for days. Females instinctively fly up the slopes to the hilltop to seek out mates. Once successfully mated, they typically descend the hill to lay their eggs on larval host plants." It added that swallowtails frequently exhibit this mating behavior. And maybe so do humans? Perhaps there's more to climbing a rugged mountain peak than "because it was there." Maybe it's just a complex display of strength and virility.
