Chico’s own butterfly man

“Beware of attack butterfly” reads a sign on the front gate leading to Sterling O. Mattoon’s north Chico home. It’s an indicator of both Mattoon’s playful personality and his lifelong love for butterflies.

The 78-year-old lepidopterist has studied butterflies since he was 7 years old. He even has a butterfly named after him—the Euphydryus editha mattooni, a type of checkerspot butterfly that he discovered.

Mattoon met UC Davis butterfly expert Arthur Shapiro “many, many, many years ago” as mutual members of the international Lepidopterists’ Society, and has worked in the field with him numerous times over the years.

“I have the greatest deal of respect for him,” Mattoon said. Shapiro, he said, is “right on” in his observations about the decline in butterfly populations and its relationship to climate change.

“Many of the same species that Art has found disappearing from the Sacramento Valley are in fact disappearing from the locations that I study and collect in, in the far northern part of the valley,” said Mattoon. “They are species that I’ve watched over the last 30 years in my yard here in Chico.” The Pontia protodice—or checkered white—and the Colias eurytheme (“the alfalfa butterfly”) are two such species.

“Above the approximately 2,500-foot elevation on mountains on both sides of the Sacramento Valley, things appear to be much more normal,” Mattoon offered. “It’s mainly here in the Sacramento Valley that [the butterflies] are finding the habitat no longer habitable.”

Valley species are increasingly moving up to higher elevations, “where they’re still finding suitable environmental conditions for their proper development,” Mattoon said. “It’s getting a little bit too dry for them—and the long summers.

“Man, in his gradual development—agriculture, roads, houses—is slowly breaking up the natural habitat for these butterflies,” added Mattoon. “Normally, a butterfly can be reintroduced to an area by migrating back, but corridors of natural habitat are being disrupted. There’s nothing to travel and breed and feed along.”