The central coast is home to the highest number of Western monarch butterflies, according to an annual count. But, the good news is tempered by the fact that the monarch butterfly’s population continues to decline across the United States.
The international non-profit organization, Xerces Society for Invertebrate Conservation released its findings this week.
Scientists tracked more than 230,000 butterflies at hundreds of sites. They found the highest numbers on the central coast.
Xerces conservation biologist, Emma Pelton said she’s not completely sure why that is.
“There are conditions there that monarchs are looking for. We also know that particularly in San Luis Obispo county and Monterey, it’s a little bit less human density. So we may have also just lost fewer sites to development in some cases,” Pelton said.
The largest count in a single location was more than 30,000 butterflies at a Nature Conservancy site in Santa Barbara County.
Next, came the Pismo State Beach Monarch Butterfly Grove with more than 16,000.
And in third place was the Morro Bay Golf Course, where scientists counted more than 10,000 monarchs.
Pelton said influences on the Western Monarch Butterfly’s survival include temperature, rainfall, and availability of milkweed and nectar.
“Last year we saw a decline of 58% and that doesn't mean all of them died. Some of them may have moved away from those sites. It's not a perfect apples of apples, but we do think that indicated a lot of mortality because of those back-to-back atmospheric rivers last year,” Peloton said.
The Western monarch’s population is down to about 5% of what it was in the 1980s.
Pelton said growing milkweed for butterflies can be extremely valuable to the insect’s survival.
