🦋 California County sees largest number of monarch butterflies in 20 years

A few years ago, the western monarch butterfly populations dropped dangerously low and many thought that the butterfly was on the brink of extinction. In November of last year, employees and volunteers at the Xerces Society for Invertebrate Conservation counted more than 129 000 individuals of the species, Jessica Griffiths who is volunteer coordinator in San Luis Obispo County shared. This number is the highest count in 20 years and back in 1998 approximately 182 000 individuals were noticed.

This rise in numbers of overwintering butterflies is a statewide trend and the Xerces Society reported that more than 300 000 of the species were counted during the annual Thanksgiving count (taking place between November 12th and December 4th last year). In 2020 only 2 000 overwintering individuals were discovered across the entire state.

“It’s hard to tell exactly why there are more monarch butterflies fluttering around overwintering groves. Part of that is because there are simply more groves being counted: 55 sites were surveyed in San Luis Obispo County this year, up from 51 last year. That number has been rising nearly every year as community members keep an eye out for the insects and report them to the Xerces Society,” Griffiths said to The Sacramento Bee.

According to Griffiths, the Xerces Society’s activities are critical in determining how many monarch butterflies migrate to San Luis Obispo County and other coastal locations in California each winter before temporarily moving away to breed.

“We need accurate data to really target restoration efforts,” she said. “And right now, I think we’re seeing it’s working — we’re seeing them rebound.”