I’ve never taken a picture, but it’s always disconcerting when there are enough butterfly carcasses in and by the side of the road that they are easy to see at driving speeds. They are everywhere, fluttering, broken and dying. Please slow down, enjoy the butterflies and the scenery. It’s a small price to pay for saving hundreds of these relatively uncommon butterflies.
This announcement from the Park Service:
Once again, we are experiencing an irruption in the population of the
butterfly, the California Tortoise Shell (Nymphalis californica) along El
Portal Road between Windy Point, to down past the hotel at parkline. This
beautiful orange and brown butterfly is being killed by vehicles in the
thousands in this area. While complete avoidance of hitting butterflies is
not possible, the carnage can be substantially reduced if drivers reduce
their speed. At around 25 mph, the butterflies tend to be swept over the
vehicle unharmed. At faster speeds, the butterflies are struck in large
numbers by the grills and windshields of vehicles. So during this period
(now through June), please slow down and enjoy this spectacle.
In most years California Tortoise Shells are a relative uncommon species.
But in certain years, they emerge in overwhelming numbers. This species
could be responsible for our county’s name, Mariposa, which is Spanish for
butterfly. The larvae of the species feed mostly on ceanothus shrubs.
Several generations of egg-larvae-pupa-adult metamorphosis may occur in
spring-summer, but the butterflies tend to move progressively higher in
elevation as the year advances. Some scientists believe this is because
plants at these elevations have new, tender growth, and lower levels of
tannins later in the season, making them more nutritious for larvae. (N.
Nicholas – 5/22/09)