Monday, April 30, 2001 Part II Department of the Interior Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Final Determination of Critical Habitat for the Bay Checkerspot Butterfly (Euphydryas editha bayensis); Final Rule VerDate 11<MAY>2000 13:59 Apr 27, 2001 Jkt 194001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\30APR2.SGM pfrm01 PsN: 30APR2 21450 Federal Register / Vol. 66, No. 83 / Monday, April 30, 2001 / Rules and Regulations DEPARTMENT OF THE INTERIOR authorized, or carried out by any populations commonly known as the Federal agency. Section 4 of the Act bay checkerspot and several populations Fish and Wildlife Service requires us to consider economic and south of Santa Clara County whose other impacts of specifying any subspecific status has been uncertain. If 50 CFR Part 17 particular area as critical habitat. We this expanded subspecific assignment is RIN 1018–AH61 solicited data and comments from the accepted by the scientific community, it public on all aspects of the proposed would represent a range extension for Endangered and Threatened Wildlife rule and economic analysis. We revised the bay checkerspot. Until such time as and Plants; Final Determination of the proposal to incorporate or address we make any new or revised Critical Habitat for the Bay new information received during the determination on the taxonomy, in this Checkerspot Butterfly (Euphydryas comment periods. final rule, we treat the threatened bay editha bayensis) DATES: This rule becomes effective on checkerspot as occurring in San May 30, 2001. Francisco Bay area counties, notably the AGENCY: Fish and Wildlife Service, ADDRESSES: counties of San Mateo and Santa Clara, Interior. Comments and materials received, as well as supporting as described in the final rule for the ACTION: Final rule. documentation used in the preparation subspecies (52 FR 35378). The bay checkerspot formerly of this final rule, will be available for SUMMARY: We, the U.S. Fish and occurred around San Francisco Bay, public inspection, by appointment, Wildlife Service (Service), designate from Twin Peaks and San Bruno during normal business hours at the critical habitat for the bay checkerspot Mountain (west of the Bay) and Contra Sacramento Fish and Wildlife Office, butterfly (Euphydryas editha bayensis) Costa County (east of the Bay), south U.S. Fish and Wildlife Service, 2800 (bay checkerspot), pursuant to the through Santa Clara County. Before the Cottage Way, Room W2605, Sacramento, Endangered Species Act of 1973, as introduction of invasive Eurasian California 95825. amended (Act). A total of approximately grasses and other weeds in the 1700s, its 9,673 hectares (23,903 acres) in San FOR FURTHER INFORMATION CONTACT: distribution may have been wider Mateo and Santa Clara counties, David Wright or Chris Nagano at the (Service 1998). In the decades preceding California, is designated as critical address above (telephone 916/414–6600; listing, the decline of the bay habitat. facsimile 916/414–6712). checkerspot was primarily attributed to Critical habitat identifies specific SUPPLEMENTARY INFORMATION: loss of habitat and fragmentation of areas that have the physical and Background habitat due to increasing urbanization. biological features that are essential to Drought and other extremes of weather the conservation of a listed species, and The bay checkerspot is a medium- have also been implicated in bay that may require special management sized butterfly with a wingspan of about checkerspot population declines considerations or protection. The 5 centimeters (2 inches (in.)). The (Ehrlich et al. 1980; Service 1998). primary constituent elements for the bay forewings have black bands along all the Recent research has identified excess checkerspot are one or more of the veins on the upper wing surface, nitrogen deposition from polluted air as following: stands of Plantago erecta, contrasting sharply with bright red, a threat to bay checkerspot habitats, due Castilleja exserta, or Castilleja yellow, and white spots. The bay to its fertilizing effect enhancing the densiflora; spring flowers providing checkerspot is 1 of about 20 subspecies growth of invasive nonnative plants nectar; pollinators of the bay of Euphydryas editha (Miller and Brown even in serpentine soil areas (Weiss checkerspot’s food and nectar plants; 1981), and differs in physical 1999). soils derived from serpentinic rock; and appearance from other subspecies in a Habitat of the bay checkerspot most space for dispersal between habitable variety of size, wing coloration, larval, commonly is found on shallow, areas. In addition, the following are and pupal characteristics (Howe 1975; serpentine-derived or similarly each primary constituent elements to be Mattoni et al. 1997). It differs from droughty or infertile soils, which conserved when present in combination LuEsther’s checkerspot (Euphydryas support the butterfly’s larval food plants with one or more of the primary editha luestherae), (a later-flying, and also includes nectar sources for constituent elements above: areas of Pedicularis-feeding subspecies of Inner adults that may also occur on other open grassland, topography with varied Coast Range chaparral in central adjacent soil types. Serpentine soils are slopes and aspects providing surface California), by being darker, and lacking high in magnesium and low in calcium, conditions with warm and moderate to a relatively uninterrupted red band and are a strong indicator of habitat cool temperatures during sunny spring demarcating the outer third of the wing. value for the bay checkerspot. The days, stable holes or cracks in the soil The black banding on the forewings of primary larval host plant of the bay and surface rocks or rock outcrops, the bay checkerspot gives a more checkerspot is Plantago erecta (dwarf wetlands providing moisture during checkered appearance than the smaller plantain), an annual, native plantain. times of spring drought. quino checkerspot butterfly The bay checkerspot usually is found In addition, the following are each (Euphydryas editha quino) of southern associated with Plantago erecta in primary constituent elements to be California (Service 1998). grasslands on serpentine soils, such as conserved when present in combination Recent publications have advocated soils in the Montara series. In Santa with one or more of the primary renaming the bay checkerspot, Clara County, the Inks and Climara soil constituent elements above: areas of Euphydryas editha bayensis, as series are related soils and often have open grassland, topography with varied Euphydryas editha editha for reasons of inclusions of Montara (U.S. Soil slopes and aspects, stable holes or historical precedence (Mattoni et al. Conservation Service 1974). Henneke cracks in the soil and surface rocks or 1997; Emmel et al. 1998). Mattoni and and other serpentine soils also occur rock outcrops, and wetlands providing co-authors (1997) have also suggested within the range of the bay checkerspot. moisture during times of spring drought. that Euphydryas editha editha ranges Populations of the bay checkerspot Section 7 of the Act prohibits from the San Francisco Bay area south formerly occurred on San Bruno destruction or adverse modification of to northern Santa Barbara County in Mountain and other locations with soils critical habitat by any activity funded, California, and includes both the that are not serpentine. We believe this VerDate 11<MAY>2000 13:59 Apr 27, 2001 Jkt 194001 PO 00000 Frm 00002 Fmt 4701 Sfmt 4700 E:\FR\FM\30APR2.SGM pfrm01 PsN: 30APR2 Federal Register / Vol. 66, No. 83 / Monday, April 30, 2001 / Rules and Regulations 21451 indicates that, with otherwise suitable temporary cessation of development) in accuracy predicted satellite habitat habitat conditions, the bay checkerspot mid to late spring. The postdiapause patches at a distance greater than 7 to is capable of living in nonserpentine larvae emerge after winter rains 8 kilometers (4 to 5 miles) from a soil areas. stimulate germination of Plantago, and primary source population were not Serpentine soils are well known for feed and bask until they are large likely to support populations (Harrison harboring rare and endemic plant enough to pupate and emerge as adults et al. 1988). species, and because the bay (Service 1998). If insufficient food is The known range of the bay checkerspot inhabits serpentine areas, available, a post-diapause checkerspot checkerspot is now reduced to Santa our critical habitat designation for the larva can re-enter diapause and emerge Clara and San Mateo counties, and it is bay checkerspot overlaps habitat of again one year or more later (Singer and patchily distributed in these locales. several federally listed plant species: the Ehrich 1979; Mattoni et al. 1997). Studies of the bay checkerspot have San Mateo thornmint (Acanthomintha Most Euphydryas editha subspecies described its distribution as an example obovata ssp. duttonii), Santa Clara exhibit generally sedentary behavior, of a metapopulation (see literature cited Valley dudleya (Dudleya setchellii), with adults frequently remaining in the in Service 1998). A metapopulation is a Coyote ceanothus (Ceanothus ferrisae), same habitat patch in which they group of spatially separated populations Tiburon paintbrush (Castilleja affinis developed as larvae (Ehrlich 1961, 1965; that can occasionally exchange ssp. neglecta), fountain thistle (Cirsium Boughton 1999, 2000). Female bay dispersing individuals. The populations