Even had I not read a newspaper or magazine, checked the
internet, gone outside to feel the rain falling on my head, or left
our own home turf, I could have known that last spring was the
wildflower event of a lifetime in Death Valley.
Even had I not read a newspaper or magazine, checked the internet, gone outside to feel the rain falling on my head, or left our own home turf, I could have known that last spring was the wildflower event of a lifetime in Death Valley.
This year, I know that it was something of a dud, and I didn’t need to drive 10 hours to find out.
The reason is a medium-sized, orange and black butterfly, the Painted Lady.
It was a warm spring afternoon last year when, as I drove along Shore Road near the San Benito-Santa Clara County line, that I noticed clouds of these showy little insects fluttering across the road, all headed north. Bingo! Death Valley must have been awash in bloom.
By the same token, we can extrapolate that Death Valley was not much of a show this spring.
The Painted Lady is one of our migratory butterflies.
Last spring, countless millions of them blew through California. Arthur Shapiro, a professor at UC Davis, is one of the nation’s leading authorities on all things butterfly. Shapiro has conducted censuses of several target species for 35 years. At one count point last year, four Painted Ladies per second fluttered by. At the same site this year, the count was four per month.
There are at least a few reasons for the rapid change. The first is Death Valley. The butterflies overwinter as eggs in the southern deserts. Taking a cue from warming days, they hatch into caterpillars, eventually becoming butterflies. They quickly head north. Subsequent generations will go all the way into the Northwest before beginning the cycle over again.
The relative lack of flowers in the deserts this year is one reason the numbers are down.
The second is the mixed up weather we’ve experienced. The mild winter, followed by a cold, wet March mixed up their clocks.
But it’s not the end for the Painted Lady. Like many butterflies, they are amazingly fecund, and a good year will have them bouncing back.
But back to Shapiro and his censuses: The long-term picture is considerably more bleak. Many butterfly numbers, while showing expected annual variations, are showing long-term declines.
One reason, Shapiro and his associates hypothesize, may be the increasingly unpredictable weather that most scientists associate with global warning.
It’s stunning to consider that something as simple as a butterfly has such stories to tell – stories about what’s going on in deserts 500 miles away and stories about the health of our entire planet.
