Pinnacles & Point Reyes Conduct Annual Butterfly Counts

The 18th annual North American Butterfly Count at Pinnacles National Park was held on June 4, 2017. Fourteen butterfly counters in eight groups hiked 31 miles, recording every butterfly they found within a 15-mile diameter circle in and around the park. This year marks the first time that counters recorded a western pygmy-blue butterfly, and the first year they encountered more than one mourning cloak butterfly. Counters also recorded many other species in much higher than average numbers, including echo blues, Bernardino square-spotted blues, Sylvan hairstreaks, mountain mahogany hairstreaks, tailed coppers, and all three swallowtail species.

Small butterfly perched on a plant
This year marks the first time that butterfly count participants at Pinnacles National Park recorded a western pygmy-blue butterfly.

© Paul G. Johnson

In total, counters documented 2,429 individual butterflies of 40 different species, in line with long-term averages. In the shorter-term, this year’s individual count was the highest since 2010, likely due to the wet winter putting an end to years of drought. In general, butterfly count results indicate that species diversity remained fairly steady throughout the drought, but numbers of individual butterflies was higher in wetter years. Complete Pinnacles count results are available online. For any questions, contact Paul Johnson.

People around a table, looking at cases of preserved butterfly specimens
After the Point Reyes count, Jerry Powell from the UC Berkeley Essig Museum of Entomology helps to identify butterfly specimens in the park's museum collections.

NPS

Point Reyes National Seashore held its 14th annual North American Butterfly Count on June 30. Eleven volunteers and butterfly experts set out to document butterflies in a similar 15-mile diameter circle in and around the park, centered on Mount Vision. They found 27 different species throughout the forest, grassland, and scrub landscape, which is about average compared to previous counts. Sightings included the federally endangered Myrtle's silverspot butterfly. Contact Ben Becker for more on the Point Reyes count.