Billions of butterflies have invaded the West, plastering windshields and clogging radiators as they flutter north to Canada on a one-way journey whose size may not be repeated for decades.
Scientists say the boom of painted lady butterflies is a dramatic sign that California's water picture is brightening. More water means more plants for the butterflies to eat, which means more butterflies."I think the butterflies are a bellwether of environmental change," said Dennis Murphy, director of the Center for Conservation Biology at Stanford University. "This is Mother Nature flexing her muscles and suggesting (she) is on a comeback."
The butterflies normally move northward each spring after hatching in Southern California and northern Mexico. But this year, there are many more of them and they are getting much farther north than normal.
Murphy put the moving painted lady population at "several billion," and said the numbers haven't been so high since 1965.
Because they are partial to weedy members of the thistle family, the swarms don't threaten California's crops. But they do make for messy driving.
"It's like somebody threw some mustard at you," said Robert Maya, a driver for Mike Demirjian Trucking Co. in Fresno. "They are all over the lights, the radiator, the windshield. I use soap and water and a long brush to get them off, but you've got to scrub hard."
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Painted Lady Butterflies
The butterflies hatch in Southern California and northern Mexico and then migrate nortward during the spring. This year billions of butterflies are on the move, with a population 100 to 1,000 times its usual size.
Description: Wingspan 2-2 1/2", Forewings orange with rosy tinge, numerous black markings and several white spots near tips.
Habitat: Meadows, gardens and open spaces.
Range: Worldwide
Flight: Spring-fall in the North, year-round in the South.
Source: The Audubon Society