SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires that, for any petition to revise the Federal Lists of Endangered and Threatened Wildlife and Plants that contains substantial scientific or commercial information that listing the species may be warranted, we make a finding within 12 months of the date of receipt of the petition. In this finding, we will determine that the petitioned action is: (1) Not warranted, (2) warranted, or (3) warranted, but the immediate proposal of a regulation implementing the petitioned action is precluded by other pending proposals to determine whether species are endangered or threatened, and expeditious progress is being made to add or remove qualified species from the Federal Lists of Endangered and Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires that we treat a petition for which the requested action is found to be warranted but precluded as though resubmitted on the date of such finding, that is, requiring a ( printed page 18937) subsequent finding to be made within 12 months. We must publish these 12-month findings in the Federal Register .

This section summarizes the information we evaluated in order to determine that the Rosemont talussnail is not a species or subspecies and cannot be listed as such under the Act, and to remove it from the candidate list. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Form for the Rosemont talussnail. This form is available on our national endangered species Web site: http://www.fws.gov/​endangered/​ (search for “Rosemont talussnail” in the Species Search box) or from the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter FWS-R2-ES-2013-0058, which is the docket number for this rulemaking.

Previous Federal Actions

On June 24, 2010, we received a petition from the Center for Biological Diversity requesting that Rosemont talussnail be listed as endangered or threatened and that critical habitat be designated under the Act. The petition clearly identified itself as such and included the requisite identification information for the petitioner required at 50 CFR 424.14(a). Our receipt of the petition coincidentally fell within the processing period for our candidate notice of review (CNOR) for Fiscal Year 2010. On November 10, 2010, we included the Rosemont talussnail in the annual CNOR (75 FR 69222) through our own internal candidate assessment process and independent of the petition process, because we had already begun the analysis prior to receiving the petition. Candidate species are species for which we have sufficient information on file to support a proposal to list as endangered or threatened, but for which preparation and publication of a proposal is precluded by higher priority listing actions. However, because we are required to address the petition and make the appropriate findings, even though we already determined the species met the definition of a candidate species, in that same CNOR, we made a 90-day substantial and a 12-month warranted-but-precluded finding for the Rosemont talussnail.

In a December 1, 2011, letter, we informed the petitioner that we had reviewed the information presented in the petition and determined that issuing an emergency regulation temporarily listing the Rosemont talussnail under section 4(b)(7) of the Act was not warranted. We explained that the species had been assigned candidate status. We also explained that per the Multi-district Litigation Stipulated Settlement Agreement ( WildEarth Guardians v. Salazar, No. 1:10-mc-00377-EGS (D. DC); Center for Biological Diversity v. Salazar, No. 1:10-mc-00377-EGS (D.DC)), we are required to submit a proposed rule or a not-warranted 12-month finding to the Federal Register for the Rosemont talussnail in Fiscal Year 2013, which ends September 30, 2013. This not-warranted 12-month finding and the associated species assessment form fulfill that requirement of the Multi-district Litigation Settlement Agreement.

Species Information

The Rosemont talussnail was first described as a member of the family Helminthoglyptidae (Phylum Mollusca; Class Gastropoda, Subclass Pulmonata) described by Pilsbry (1939, pp. 348-349) from the northern end of the Santa Rita Mountains near Rosemont, Pima County, Arizona. Bequaert and Miller (1973, p. 115) and Turgeon et al. (1988, p. 146) subsequently recognized the Rosemont talussnail in their respective reviews of mollusks. However, Hoffman et al. (2012, pp. 310-313) recently demonstrated that the Rosemont talussnail was described in error and is actually the same species as the Santa Rita talussnail ( Sonorella walkeri).

Initially, Pilsbry and Ferriss (1923, p. 90) treated the Rosemont talussnail from the northern end of the Santa Rita Mountains (Station 49 near Rosemont) as Sonorella hesterna.Pilsbry (1939, p. 349) later described the Rosemont talussnail as a full species, S. rosemontensis, based on a single shell collected at Station 49 (Ferriss 1917-1918, p. 2; Hoffman et al. 2012, pp. 1-2). However, in his description of S. rosemontensis, Pilsbry (1939, p. 349) stated, “It was formerly considered to be identical with S. hesterna, but the well developed threads of the embryonic shell apparently indicate a different species. Were it not for the very different verge [male genitalia], this form would hardly be separated from S. walkeri.” Hoffman et al. (2012, p. 309) determined that Pilsbry (1939) confused the shell of the specimen he dissected with that of S. hesterna, and mistakenly dissected the gentilia from a different species of Sonorella. Pilsbry (1939, p. 349) described the genitalia as “very closely related to S. arida * * * being of the same general character.” Based on his writings, Pilsbry was well aware of the fact that the distinct features of S. rosemontensis resembled two different known species.

The disparities in reproductive structures described for the Rosemont talussnail, Sonorella rosemontensis, were first noted in earnest by Miller (1967, p. 70) where he stated the genitalia “resemble those of S. walkeri.” In discussing the Pilsbry (1939) description, Miller (1967, p. 70) went on to say that, “It is probable that he [Pilsbry] dissected a specimen of S. tumamocensis linearis by mistake.” Upon examination of genitalia, Miller (1967, p. 70) stated, “ S. rosemontenis is closely related in all respects to S. walkeri.” These anatomical examinations revealed that the Rosemont talussnail, S. rosemontensis, closely resembles the Santa Rita talussnail, S. walkeri, strongly suggesting that the Rosemont talussnail may only be a subspecies of or the same species as the Santa Rita talussnail (Miller 1967, p. 70; Miller 1978, p. 115). In fact, the drawing of the reproductive organs of the Rosemont talussnail presented in Miller (1967, p. 260) does not appear to differ in any significant way from the reproductive organs of the Santa Rita talussnail (Hoffman et al. 2012, p. 309).

Although it was suggested that the Rosemont talussnail may be a subspecies of the Santa Rita talussnail (Miller 1967, p. 70; Miller 1978, p. 115), there is no information indicating such. A subspecies is a category in biological classification that ranks immediately below a species; it designates a population of a particular geographic region morphologically or genetically distinguishable from other such populations of the same species and capable of interbreeding successfully with them where its range overlaps theirs. Evidence suggests that the Rosemont and Santa Rita talussnail are simply the same species. Hoffman et al. (2012, p. 313) found no discernible differences in the shapes or sizes of the male or female reproductive organs among specimens, nor was there any discernible differences in the shape of the shells between the Rosemont talussnail and the Santa Rita talussnail. Therefore, based on the morphological data and the sympatric range of the Santa Rita and the Rosemont talussnails, Hoffman et al. (2012, p. 313) concluded that the Rosemont and Santa Rita talussnail are the same species.

Evaluation of Listable Entity

Under the Act, a “species” is defined as including any subspecies of fish or wildlife or plants, and any distinct population segment (DPS) of any species of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 1532(16)).

Based on our review of the best available information, the original ( printed page 18938) description of the Rosemont talussnail (previously Sonorella rosemontensis) was made in error, and the taxonomic entity is actually the same species as the Santa Rita talussnail ( S. walkeri). Therefore, we conclude that the Rosemont talussnail ( S. rosemontensis) is not a species under section 3(16) of the Act. We have reviewed the relevant literature, and we also find that the Rosemont talussnail is not a subspecies of the Santa Rita talussnail. Additionally, invertebrates are precluded by statute from DPS consideration. Therefore, we conclude that the petitioned entity does not constitute a listable entity and cannot be listed under the Act.

Finding

Based on the best scientific and commercial information available, we find that the Rosemont talussnail is not a listable entity and cannot be listed under the Act. The Rosemont talussnail ( Sonorella rosemontensis) was subsumed into the Santa Rita talussnail ( S. walkeri), which is a widespread and common species whose distribution extends across southern Arizona from the Santa Rita and Atascosa Mountain Ranges in Santa Cruz County; the Whetstone Mountains of Cochise County; and south into Sonora, Mexico (Pilsbry and Ferris 1915, p. 395; Bequaert and Miller 1973, p. 115; Arizona Game and Fish Department 2008, p. 2). Please submit any new information concerning the status of, or threats to, the Santa Rita talussnail to our Arizona Ecological Services Field Office (see ADDRESSES ) whenever it becomes available. New information will help us monitor the Santa Rita talussnail and encourage its conservation.

References Cited

A complete list of references cited is available on the Internet at http://www.regulations.gov at Docket Number FWS-R2-ES-2013-0058, in the Species Assessment and Listing Priority Assignment Form on the Internet at http://www.fws.gov/​endangered/​, and upon request from the Arizona Ecological Services Field Office (see ADDRESSES ).

Authors

The primary authors of this notice are the staff members of the Arizona Ecological Services Field Office.

Authority

The authority for this section is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).