A critical habitat of more than 18,000 acres designated for the threatened Bay checkerspot butterfly will formally go into effect in late
September, a U.S. Fish and Wildlife Service spokesman said Wednesday.
On Tuesday the 18,293-acre critical habitat was published in the federal register, Fish and Wildlife Service spokesman Al Donner said. It will formally go into effect 30 days after it was published.
The grassland habitat, 90 percent of which is in Santa Clara County and the other 10 percent in San Mateo County, is intended to help the butterfly recover and begin to multiply, Donner said. Most of the territory in Santa Clara County is located east of U.S. Highway 101, while in San Mateo County the protected areas are located in the Redwood City hills and around
San Bruno Mountain.
A critical habitat is essentially a line drawn on a map, Donner said. It is more a bureaucratic move, required by the Endangered Species Act, to show the area where the threatened species is known to reside. Any federal agency involved in the area of the critical habitat must consult with the Fish and Wildlife Service to determine the effect of their action.
The 2-inch butterfly with black bands and red, orange and white spots is found only in the San Francisco Bay Area and its population is diminishing due to fewer places where the plants it feeds on grow.
Biologist Shaye Wolf, with the Center for Biological Diversity, has blasted the Fish and Wildlife Service, saying instead of “providing
adequate, protected areas to help the Bay checkerspot survive” the service is “cutting holes in its safety net.”
The Center is dedicated to restoring natural habitats and grazing areas to animals and insects that are endangered by developments or other man-made encroachments on nature, according to its Web site.
Wolf and the center argue that the Fish and Wildlife Service cut the original critical habitat by almost a quarter from the one introduced in 2001.
Donner said the reason for the drop in critical habitat acreage is due to development that was erected after 2001 in areas that had been marked. Another reason is that when crews from Fish and Wildlife went out to survey the areas, some were heavily wooded and not suited to the butterfly.
According to the Center, the species is affected by global warming, because extreme precipitation, such as droughts and floods,
decreases the availability of food for the larvae.
Bay checkerspot butterflies prosper in warmer grassland areas and feast mainly on dwarf plantain, according to the Fish and Wildlife Service. They were designated as threatened in 1987 under the Endangered Species Act.
“We zeroed in on a particular kind of soil that the species needs, and where the butterflies are known to have existed in recent years,” Donner said. “We have a strong, solid designation where the species will survive and thrive.”