Federal Register / Vol. 60, No. 173 / Thursday, September 7, 1995 / Proposed Rules 46569 requested action may be warranted. The been fenced to restrict access, and the ssp. verecunda in chaparral and mixed 90-day finding was published in the other two populations are expected to evergreen plant communities is an Federal Register on August 19, 1992 (57 be protected by fencing when indication that this taxon may be more FR 37513). A status review was ownership of the Presidio is transferred widely distributed and have broader continued for this category 2 candidate from the Department of Army to the habitat affinities than previously species (58 FR 51186; September 30, National Park Service. Invasive non- believed. Chaparral covers an extensive 1993). native vegetation is encroaching on portion of the Coast Ranges in the San Silene verecunda ssp. verecunda is a some populations of S. verecunda ssp. Francisco Bay area. Consequently, the perennial herb in the pink family verecunda. On the Presidio, however, unknown overall status of the taxon (Caryophyllaceae) that grows from 10 to there are ongoing efforts to remove the makes any assumptions about 70 centimeters (4 to 28 inches) tall. Each invasive species. There is no vulnerability of S. verecunda ssp. flower has five pink to rose colored quantitative trend data to assess the verecunda to current threats notched petals, and the purplish sepals extent to which S. verecunda ssp. unsupportable at this time. are united into a tube, making the verecunda has or will be impacted by The Service has reviewed the petition, flower look bell-shaped. non-native plants. Therefore, such other available literature and Silene verecunda ssp. verecunda threat to this species is not known to be information, and consulted with previously was reported to occupy open immediate or imminent. The known biologists and researchers familiar with grassy areas in sandy to rocky soils in populations of S. verecunda ssp. Silene verecunda ssp. verecunda. On coastal strand, coastal prairie, and verecunda that occur on the Presidio are the basis of the best scientific and coastal scrub plant communities ranging unlikely to be affected by toxic waste commercial information available from San Francisco south to Santa Cruz site studies and clean-up. This species regarding S. verecunda ssp. verecunda, County (Young 1979). Recently, S. does not occur near the area where these the Service finds that the petitioned verecunda ssp. verecunda has been activities most likely would occur (Peter action is not warranted at this time reported to occur in chaparral and Lacivita, U.S. Army Corps of Engineers, because there is insufficient information mixed evergreen forest plant pers. comm. 1993). Neither disease, about the taxon’s status and its communities (Skinner and Pavlik 1994; predation, or overutilization are known vulnerability to threats. The Service will Lion Baumgartner, Thomas Reid to be a threat to S. verecunda ssp. Associates, in litt. 1994). Historical continue to maintain S. verecunda ssp. verecunda. verecunda as a species of concern. The populations from Lake Merced and Stochastic (random) and natural Service encourages all interested parties Mission Dolores in San Francisco have events can cause population to investigate the population status of S. been extirpated due to commercial and fluctuations or even population verecunda ssp. verecunda and its residential development. Currently extirpations but are not usually a vulnerability to threats, with particular there are about 2,000 known individuals concern until the number of individuals reference to the southern and central of S. verecunda ssp. verecunda found or geographic distribution become primarily on private or non-Federal vulnerably small. A combination of portions of its range and populations land, including about 700 plants on San remnant small populations, a narrow occurring in chaparral and mixed Bruno Mountain (Lion Baumgartner, in range, and restricted habitat, could evergreen plant communities. If litt. 1994). Three populations, totaling make all or a significant part of any additional data becomes available in the seven hundred plants according to a population susceptible to destruction future, the Service may reassess the 1993 census, occur on the Presidio in from stochastic natural events, such as listing priority for this species or the San Francisco. It is not known how flood, drought, disease, or other natural need for listing. much potential habitat, or numbers of occurrences (Shaffer 1981, Primack Author individuals may occur from Montara 1993) such as genetics and reproductive Mountain in San Mateo County to success. The primary author of this document Rancho Del Oso in Santa Cruz County. No demographic studies exist to is Kirsten Tarp (see ADDRESSES section). The northern range of Silene indicate that the reproductive success of Authority verecunda ssp. verecunda overlaps a Silene verecunda ssp. verecunda is rapidly urbanizing portion of the San threatened, or is vulnerable to adverse The authority for this action is the Francisco Bay area. Most of the habitat impacts from random events. There is Endangered Species Act of 1973, as within the northern part of the range of no evidence at this time to suggest that amended (16 U.S.C. 1531 et seq.) S. verecunda ssp. verecunda has been reproductive capacity is a factor posing Dated: July 24, 1995. disturbed or eliminated except for areas a threat to the survival of the species. John G. Rogers, on San Bruno Mountain that are Low seed production in perennial Acting Director, Fish and Wildlife Service. protected for the conservation of the plants is not necessarily a trait that endangered mission blue butterfly makes a species vulnerable to [FR Doc. 95–22172 Filed 9–6–95; 8:45 am] (Icaricia icarioides missionensis). extinction. Huenneke (1986) indicates BILLING CODE 4310±55±P Implementation of the San Bruno that low genetic diversity in plants is Mountain Habitat Conservation Plan rarely seen as a threat to their survival. 50 CFR Part 17 (HCP) developed under sections Intrinsically, most rare plants are likely 10(a)(1)(B) and 10(a)(2)(A) of the Act has to have genetic systems enabling them Endangered and Threatened Wildlife conserved habitat for the butterfly, and to cope with the genetic consequences and Plants; 90-Day Finding for a indirectly benefits S. verecunda ssp. of rarity. Petition to List the Mohave Ground verecunda by maintaining the habitat in The population status of S. verecunda Squirrel as Threatened which both species occur. On federally ssp. verecunda and its vulnerability to owned land on the Presidio in San threats in the central part of its range AGENCY: Fish and Wildlife Service, Francisco, increased human access and (i.e., Montara Mountain in San Mateo Interior. activities potentially threatened three County to Rancho del Oso in Santa Cruz ACTION: Notice of 90-day petition populations of S. verecunda ssp. County) are not known at this time. finding. verecunda. One of these populations has Moreover, the discovery of S. verecunda 46570 Federal Register / Vol. 60, No. 173 / Thursday, September 7, 1995 / Proposed Rules

SUMMARY: The U.S. Fish and Wildlife not currently available indicating that found. Without precise habitat Service (Service) announces the 90-day listing as endangered or threatened is information, it is difficult to assess the finding on a petition to list the Mohave warranted. severity of habitat loss. In addition, ground squirrel (Spermophilus The Mohave ground squirrel ranges insufficient data are available on mohavensis) under the Endangered throughout the northwest portion of the specific habitat requirements to Species Act (Act) of 1973, as amended. Mojave Desert of California. The species precisely delineate the acreage of The Service finds that the petition did spends about 7 months a year, usually Mohave ground squirrel habitat. not present substantial information from August to February, estivating in Specific information on habitat indicating that the petitioned action burrows. Timing of estivation is requirements would also facilitate the may be warranted. presumably related to sufficient rating of areas based on habitat quality. DATES: The finding announced in this accumulation of fat reserves In making a finding as to whether a document was made on August 4, 1995. (Bartholomew and Hudson 1960, Ingles petition presents substantial commercial Comments and materials related to this 1965, Tomich 1982). Entrance into and scientific information to indicate petition finding may be submitted to the estivation may begin from June to the petitioned action may be warranted, Field Supervisor at the address listed September. In years with abundant food the Service must consider whether the below. supplies, adults may enter estivation in petition is accompanied by a detailed ADDRESSES: Information, data, late June and juveniles may enter in late narrative justification [50 CFR comments, or questions concerning the July. Adults are more likely than § 424.14(b)(2)(ii)]. The regulations status of the petitioned species should juveniles to enter estivation early require the Service to ‘‘consider whether be submitted to the Field Supervisor, because adults do not need to gain as such petition * * * [p]rovides Fish and Wildlife Service, Ventura Field much weight as juveniles to survive the information regarding the status of the Office, 2493 Portola Road, Suite B, long estivation underground (Gustafson species over all or a significant portion Ventura, California 93003. The complete 1993). Males tend to enter estivation of its range’’ [50 CFR § 424.14(b)(2)(iii)], file for this finding is available for earlier than females because they do not including current distributional and public inspection, by appointment, need to put energy into milk production threat information. Furthermore, the during normal business hours at the and feeding of young before they store Service is required to ‘‘consider whether above address. fat (Leitner and Leitner 1992). Mating such petition * * * [i]s accompanied by occurs soon after emergence from appropriate supporting documentation FOR FURTHER INFORMATION CONTACT: Kate estivation and a litter of 4–6 young are in the form of bibliographic references, Symonds at the Ventura Field Office born after a gestation period of 28–30 reprints of pertinent publications, (see ADDRESSES section) or at 805/644– days. Mohave ground squirrels are copies of reports or letters from 1766. generally less active when air authorities, and maps’’ [50 CFR SUPPLEMENTARY INFORMATION: temperatures drop below 88 °F or § 424.14(b)(2)(iv)]. ° Background exceed 98.1 F (Bartholomew and In assessing the substantiality of this Hudson 1960). The diet consists of petition, the Service reviewed several Section 4(b)(3)(A) of the Endangered seeds, flowers, forbs, shrubs, grasses, published and unpublished studies, Species Act of 1973, as amended (16 fungi, and arthropods, although the agency documents, literature syntheses, U.S.C. 1533 et seq.) (Act), requires that species has demonstrated flexibility in commercial data, and field sighting the Service make a finding on whether utilizing food items as annual records. The Service also interviewed a petition to list, delist, or reclassify a availabilities change (Recht 1977, researchers and other persons familiar species presents substantial scientific or Leitner and Leitner 1992). with the species’ biology. In addition, commercial information to indicate that Mohave ground squirrels have been the petitioner was contacted to provide the petitioned action may be warranted. found in all vegetation associations and additional supporting information, This finding is to be based on all up to 5,600 feet in elevation within its which he was unable to provide. On the information available to the Service at 7,600 square mile range (Hoyt 1972, basis of the best scientific and the time the finding is made. To the Gustafson 1993). Gustafson (1993) commercial information available, the maximum extent practicable, this reported that Mohave ground squirrels Service finds that the petition did not finding is to be made within 90 days of have been found in Holland’s (1986) provide reliable data, recent or the date the petition was received, and communities of Mohave wash scrub, otherwise, throughout the species’ range the finding is to be published promptly desert sink scrub, and desert regarding specific habitat requirements, in the Federal Register. If the finding is greasewood scrub. Nonetheless, the and population abundance and trends. that substantial information was species appears to prefer large alluvial- Moreover, the petition did not include presented, the Service also is required to filled valleys and deep, fine-to-medium any data linking some activities (e.g., commence a review of the status of the textured soils vegetated with creosote rural development, off-road vehicle use, species. bush scrub, shadscale scrub, or alkali Fort Irwin training) with long-term On December 13, 1993, the Service sink scrub wherever desert pavement is absence of the ground squirrel or on the received a petition dated December 6, absent (Aardahl and Roush 1985). The extent to which these activities may be 1993, from Dr. Glenn R. Stewart of Mohave ground squirrel rarely is found degrading habitat. Also, the petitioner California Polytechnic State University, in mountainous or rocky terrain, or dry failed to provide convincing data that Pomona, California, requesting the lake beds, although exceptions have grazing by domestic sheep and cattle Service to list the Mohave ground been recorded (Zembal and Gall 1980, adversely affects the habitat of the squirrel (Spermophilus mohavensis) as a Wessman 1977). Mohave ground squirrel. Finally, the threatened species. The species is a Excluding mountainous or rocky petition did not include any information category 2 candidate (November 15, areas, and dry lake beds, the Mohave to assess the extent and configuration of 1994; 59 FR 58988), which was first ground squirrel habitat is distributed habitat loss due to fragmentation to included in this category on September over an estimated 7,200 square miles determine whether this threatens the 18, 1985. Category 2 includes taxa for (Gustafson 1993). This figure excludes species. Therefore, given the which sufficient information on those plant communities and soil types uncertainties associated with urban biological vulnerability and threats is in which the species has never been growth and other threats in the Mojave Federal Register / Vol. 60, No. 173 / Thursday, September 7, 1995 / Proposed Rules 46571

Desert, and the lack of credible studies ADDRESSES: Data, information, originate in the Sierra Nevada mountain on the biological status of the species, comments, or questions concerning this range from meltwater of the previous the Service finds that the petition did petition should be sent to the U.S. Fish winter’s snowpack. When the net inflow not present substantial information and Wildlife Service, Field Supervisor, is less than the net evaporation, salinity indicating that the listing of the Mohave Ventura Field Office, 2493 Portola Road, concentrations increase as the lake’s ground squirrel may be warranted. Suite B, Ventura, California 93003. surface elevation declines. Beginning in Given these data uncertainties, the FOR FURTHER INFORMATION CONTACT: 1941, the City of Los Angeles Mohave ground squirrel will remain a Cathy R. Brown (see ADDRESSES section) Department of Water and Power (Los species of concern to the Service. telephone 805–644–1766; facsimile 805/ Angeles) diverted water from four of the 644–3958. five streams flowing into Mono Lake for References Cited its municipal and domestic use. The A complete list of references used in SUPPLEMENTARY INFORMATION: water exports have caused a decline of the preparation of this finding is Background 14 meters (m) (45 feet (ft)) in lake surface elevation and a 100 percent available, upon request, from the Section 4(b)(3)(B) of the Endangered increase in lake salinity (Dana and Lenz Ventura Field Office (see ADDRESSES Species Act of 1973, as amended (16 1986). Mono Lake surface elevation was section). U.S.C. 1531 et seq.), requires that for about 1,956 m (6,417 ft) above mean sea Author any petition to revise the Lists of level and the water salinity was about Endangered and Threatened Wildlife The primary author of this document 48 grams per liter (parts per thousand and Plants that contains substantial (ppt)) before water exports began in is Kate Symonds, Ventura Field Office scientific and commercial information a (see ADDRESSES section). 1941 (Vorster 1985, Botkin et al. 1988). finding be made within 12 months of Currently, the lake surface elevation is Authority the date of receipt of the petition on about 1,943 m (6,375 ft) with a salinity whether the petitioned action is: (a) not The authority for this action is the of 100 ppt (M. Davis, Mono Lake warranted, (b) warranted, or (c) Endangered Species Act of 1973, as Committee, pers. comm., 1994). warranted but precluded from amended (16 U.S.C. 1531 et seq.). High salinities deleteriously affect immediate proposal by other pending Mono Lake brine shrimp reproduction. Dated: August 4, 1995. proposals. Such 12-month findings are In addition, female age at reproduction John G. Rogers, to be published promptly in the Federal increases significantly, and the number Acting Director, Fish and Wildlife Service. Register. of ovoviviparous broods per year and [FR Doc. 95–22171 Filed 9–6–95; 8:45 am] In a petition dated June 16, 1987, and brood size decrease significantly as BILLING CODE 4310±55±P received by the Service on June 19, salinity increases from 76 ppt to 118 ppt 1987, the Service was requested by Dr. (Dana and Lenz 1986). Some of these Dennis D. Murphy, of the Center for negative effects on adult Mono Lake 50 CFR Part 17 Conservation Biology, Stanford brine shrimp fecundity occur at present University, to list the Mono Lake brine lake salinities. At the current salinity of Endangered and Threatened Wildlife shrimp as an endangered species. The about 100 ppt, about 50 percent of Mono and Plants; 12-Month Finding for a petition cited threats to this species that Lake brine shrimp cysts do not hatch Petition to List the Mono Lake Brine would result from increasing salinity (Dana and Lenz 1986). Shrimp as Endangered caused by continued water diversions In September 1994, the California from the streams tributary to Mono State Water Resources Control Board AGENCY: Fish and Wildlife Service, Lake. The Service’s 90-day finding, that # Interior. issued Water Rights Decision 1631, substantial information existed revising Los Angeles’s water rights to ACTION: Notice of 12-month petition indicating that the petitioned action provide greater protection to public finding. may be warranted, was published in the trust values of Mono Lake. The State Federal Register on August 19, 1988 (53 Board’s decision establishes an average SUMMARY: The Fish and Wildlife Service FR 31721). A status review was initiated lake level of 1,948 m (6,392 ft), with an (Service) announces a 12-month finding at that time. A timely finding on the estimated salinity of 69 ppt. These for a petition to list the Mono Lake brine subject petition was precluded by conditions are expected to be beneficial shrimp (Artemia monica) under the higher priority listing actions until the to brine shrimp reproduction and Endangered Species Act of 1973, as present time. should provide adequate protection for amended (Act). This aquatic crustacean The Mono Lake brine shrimp is a the long-term viability of the Mono Lake occurs only in Mono Lake, Mono species of fairy shrimp found only in brine shrimp. County, California. A recent decision by Mono Lake, Mono County, located east On the basis of the best available the California State Water Resources of the Sierra Nevada Mountain Range in scientific and commercial information, Control Board to revise the water rights northeastern California. It is a the Service finds that listing the Mono of the City of Los Angeles in the Mono branchiopod crustacean in the order Lake brine shrimp is not warranted Basin has apparently removed the threat Anostraca whose members have stalked because the taxon is not in danger of of habitat degradation to the Mono Lake compound eyes. It is characterized by extinction or likely to become so in the brine shrimp. As a result of the an elongated body trunk of 20 or more foreseeable future. The Service will protections offered by this decision, the segments, and the absence of a carapace. reclassify the Mono Lake brine shrimp Service finds that the Mono Lake brine Mono Lake may be the second oldest as a category 3C candidate for listing shrimp does not meet the definition of continuously existing lake in North and will continue to monitor its status. an endangered or a threatened species at America with an estimated age ranging Category 3C candidates are those taxa the present time. from 500,000 to one million years that have proven to be more abundant DATES: The finding announced in this (Vorster 1985). It is a terminal lake, that or widespread than previously believed document was made on July 24, 1995. is, a closed system with no outlet flows. and/or those that are not subject to any Comments from all interested parties Lake level is maintained by five identifiable threat. If information will be accepted until further notice. principal inflowing streams that becomes available indicating that the