The Santa Clarita skies are aflutter as butterflies fill the air on their migration through Southern California.
“Never in my 53 years have I seen them in these numbers,” local resident Thora VanDerwilt said in a Facebook post.
They’re “painted ladies” to be exact, and nearly one billion are migrating across the state at speeds of up to 25 mph, according to Art Shapiro, an ecologist at the University of California Davis who has been tracking butterflies for almost 50 years.
After spending the winter in the deserts of northern Mexico, these painted ladies are headed to their breeding grounds in the Pacific Northwest, Shapiro said.
“Yesterday it was almost to the point where they would qualify as a cloud because there were so many of them,” Yanega said.
The migration itself isn’t out of the ordinary — these butterflies are natives — but the unusually heavy rain and cooler temperatures have helped their population levels soar, according to Doug Yanega, senior museum scientist at University of California Riverside’s Entomology Research Museum.
“At first it looked like leaves blowing in wind, but there was no wind,” local resident Mike McCleary said. “On my drive home I counted 40 butterflies at one red light, but there must have been hundreds on the entire drive.”
This is a welcome change as the number of butterflies were at a record low last year, according to Shapiro’s research. Scientists say there haven’t been this many butterflies traveling through the state since 2005 after one of the wettest years in California’s history.
“It was a unique and beautiful sight,” local resident Karen Verkouteren said. “I’ve lived in Santa Clarita for 19 years and have never seen anything like it.”
Butterflies lay their eggs on plants so that the caterpillars will have something to eat after they hatch, so with such green vegetation this year, they have plenty of food to munch on, Shapiro said.
“The cooler temperatures prolong the time it takes for the plants to die, which means that if the weather stays cool and everything stays green, we could continue seeing them until at least a month after the plants dry out,” Yanega said.
The butterflies then use that food store as fuel to fly hundreds of miles without stopping, and when their reserve runs out, they stop and breed, which may not be until they reach central or northern California, according to Shapiro. Then, the next generation will continue the trek north.
“You’ll see that there are two distinct sizes of butterflies migrating,” Yanega said. “Some look very small for painted ladies, so those are probably the local products and are the first generation that just hatched and are continuing north.”