Smith’s Blue Butterfly (Euphilotes enoptes smithi)
Male Smith’s blue butterfly - Photo © Richard A. Arnold - www.ecsltd.com
The Smith’s blue is a relatively small (less than one-inch wingspan) butterfly endemic to central California. The males are a brilliant blue color, while the females are brown; both sexes have a red-orange band across the underside of the hind wings. The Smith's Blue has a light undersurface ground color with noticeable black markings and a dull black terminal line.
DISTRIBUTION AND RANGE
Historically, the Smith’s blue has always been restricted to the coastal areas of central California, primarily coastal sand dunes from the Salinas River to Del Rey Creek. The current known distribution is restricted to portions of Monterey, San Mateo, and Santa Cruz counties, where it occurs in scattered populations in association with coastal dunes, inland sand dunes, cliff-side coastal scrub and chaparral, and grassland habitats. Since two species of native buckwheat serve as the host plants, the continued existence of these plants is the key limiting factor for the butterfly.
Eleven occupied sites are in or near the Los Padres National Forest, including Big Sur Park, Monterey Ranger District, Burns Creek, along the Nacimiento-Ferguson Road, Kirk Creek, and Gorda Horse Pasture. The species' current range encompasses an 80-mile linear strip along coast of central California, 45 miles of which lie within Los Padres National Forest. On the Monterey Ranger District, there is an estimated 2,000 acres of potential habitat, based on the distribution of seacliff buckwheat. A total of 518 acres has been identified as key habitat, and modeled habitat is 10,856 acres in the Los Padres National Forest. No comprehensive surveys have been conducted on the Monterey Ranger District.
Monterey Ranger District in Big Sur, CA. Photo courtesy of Ventana Wilderness Alliance.
Smith’s blue butterflies spend their entire lives in association with two buckwheat plants in the genus Eriogonum — seacliff buckwheat and coast buckwheat — which provide food for the larvae and nectar, resting, basking, mate location, and copulation sites for the adults. Both sexes stay relatively close to the host plants; studies show they remain within 200 feet. The flight season for the Smith's Blue is closely associated with the flowering period of the buckwheat plants, from mid-June to early September. Males emerge first, followed by the females about a week later. Adults live for about one week, but emergences are dependent on climatic variations in the flowering time of host plants. Only one generation per year is produced. Courtship and mating occur on or near buckwheat flower heads.
The Smith’s blue was federally listed as an endangered species in 1976. Critical habitat was proposed for the species in 1977, but was never designated. A recovery plan for the butterfly was published in 1984, but it needs to be updated to reflect new information. The Fish and Wildlife Service conducted a Status Review for the Smith’s blue butterfly in 2003. The Service proposed downlisting the species from endangered to threatened in 2006 even though its habitat and the species are likely continuing to decline. The Service acknowledges it does not know what the population size is, does not know what the population trend is, and has not established scientific recovery criteria or goals. The Center will oppose changing the endangered listing.
Female Smith’s blue butterfly - Photo © Richard A. Arnold - www.ecsltd.com
THREATS TO THE SPECIES
Threats to the butterfly include habitat loss and degradation due to development, livestock grazing, wildfire suppression, invasion of exotic plants, sand mining, off-road vehicles and bikes, foot traffic, and the maintenance, repair, and use of roads and trails. Even fugitive dust may cause adults to leave habitat and may reduce the palatability of buckwheat for feeding larvae.
Cattle and other livestock grazing on the coastal allotments of the Los Padres National Forest near Big Sur threatens the Smith’s blue butterfly in several ways. Livestock trampling can kill or stunt the growth of seacliff buckwheat, the butterfly’s host plant. Livestock also can crush butterfly pupae, larvae and eggs. Grazing also plays a major role in promoting weed infestations of invasive pampas grass and noxious yellow star-thistle, which outcompete the native buckwheat host plants.
Since 2001, the Center has filed a number of appeals and threatened legal actions to reign in destructive livestock grazing allowed by the Forest Service in the Monterey Ranger District of the Los Padres National Forest, to protect Smith’s blue butterflies and their native buckwheat habitat. The Center submitted a comprehensive conservation alternative in 2003 for management of the four Southern California national forests, which specifically suggested management strategies for protecting the Smith’s blue butterfly. In 2006 the Center appealed the Forest Service’s approval of deficient land management plans for these forests.
Smith’s blue butterfly larva - Photo © Richard A. Arnold - www.ecsltd.com
Center Actions to Protect Smith’s Blue Butterfly:
• In July 2006 the Center and a coalition of conservation groups appealed the Forest Service’s approval of flawed land management plans for four southern California national forests, which would allow harm to numerous listed species, including the Smith’s blue.
• In November 2005 the Center and central California coast conservation groups appealed (for the third time) a controversial Forest Service decision to expand livestock grazing in endangered species habitat along the Big Sur Coast in the Los Padres National Forest.
• In March 2005 the Forest Service withdrew (for the second time) its decision to re-authorize and dramatically expand grazing leases on six grazing allotments covering over 24,000 acres along the Big Sur coast, including Smith’s blue habitat.
• In January 2005 the Center appealed the Big Sur grazing decisions (for the second time).
• In July 2003 the Center forced the Forest Service to remove livestock from the Gorda grazing allotment on the Big Sur coast. Grazing was suspended in response to threatened legal action by the Center over impacts to the Smith’s blue butterfly and other listed species.
• In December 2002, livestock grazing was suspended on 5,700 acres of the Big Sur coast after threat of legal action by the Center, to protect Smith's Blue butterfly habitat on two Forest Service grazing allotments.
• In June 2002 the Fish and Wildlife Service designated 18,830 acres of critical habitat in Monterey and Santa Cruz counties for the Monterey spineflower, in keeping with a court order obtained by the Center. This spineflower occurs coexists with Smith's blue butterflies, so the designation protects habitat for the butterfly as well.
• In April 2002 the Center led a group of environmental organizations, scientists and technical experts in presenting a visionary plan for management of southern California's four national forests that would enhance protections for listed species, including the Smith’s blue butterfly, on the Los Padres National Forest.
• In February 2002, the Forest Service withdrew its decision (for the first time) to increase livestock grazing on eight federal grazing allotments along the Big Sur coast. A Center appeal temporarily kept about 30,000 acres cattle-free, including habitat for the Smith’s blue.
• In December 2001 the Center appealed (for the first time) a Forest Service decision to allow renewed cattle grazing on Smith’s blue butterfly habitat in Big Sur.
• In March 2000 the Center reached a landmark legal agreement with the Forest Service to protect more than 50 endangered species in southern California's four national forests, including the Smith’s blue butterfly. The Forest Service was required to amend forest management plans to address endangered species protections and to remove livestock from several sensitive areas.