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Endangered and Threatened Wildlife and Plants; 90-day Finding for a Petition to Delist the Mexican Bobcat

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Fish and Wildlife Service, Interior.


Notice of 90-day petition finding and initiation of status review.


We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding for a petition to delist the Mexican bobcat (Lynx rufus escuinapae) under the Endangered Species Act of 1973, as amended. After reviewing the petition and available scientific and commercial information, we find that the petition presents substantial information indicating that listing may no longer be warranted. With the publication of this notice, we are initiating a status review of the Mexican bobcat. In addition to requesting information on the status of the Mexican bobcat, we are requesting information on whether the subspecies designation is taxonomically valid. If not valid, we also request information on the status of Start Printed Page 39591the listed entity within Mexico for the purpose of determining if the Mexican population constitutes a distinct population segment (DPS) or constitutes a significant portion of the range of the species. We will prepare and publish a 12-month finding.


The finding announced in this document was made on June 11, 2003. To be considered in the 12-month finding for this petition, comments and information should be submitted to us by September 30, 2003.


Submit information, comments, or questions concerning this petition finding to the Chief, Division of Scientific Authority, U.S. Fish and Wildlife Service, 4401 N. Fairfax Drive, Rm 750, Arlington, VA 22203 (facsimile number 703-358-2276; E-mail address: The petition, supporting information, and comments will be available for public inspection, by appointment, from 8 a.m. to 4 p.m., Monday through Friday, at the above address.

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Karen L. Anderson, Division of Scientific Authority (see ADDRESSES section) (telephone 703-358-1708; facsimile 703-358-2276).

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Section 4(b)(3)(A) of the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1533(b)(3)(A)), requires us to make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information indicating that the petitioned action may be warranted. This finding is to be based on all information available to us at the time the finding is made. To the maximum extent practicable, this finding is to be made within 90 days of the date the petition was received, and a notice of the finding is to be published promptly in the Federal Register. If the finding is that substantial information was presented, we are required to promptly commence a review of the status of the involved species. After completing the status review, we will issue an additional finding (the 12-month finding) on whether delisting is, in fact, warranted.

On July 8, 1996, we received a petition dated June 30, 1996, from the National Trappers Association, Inc., Bloomington, Illinois. The petition and cover letter clearly identified itself as such and contained the name, address, and signature of the petitioning organization's representative. Information relating to the taxonomy, the present population status and trends, and threats were included in the petition. The petition requested that we delist the Mexican bobcat under the Act, and noted that downlisting to threatened status would not be an appropriate alternative. In a letter dated November 4, 1996, we acknowledged receipt of the petition (Service, in litt., 1996). We stated that we would address the petition as soon as possible. Due to staffing and budget constraints, we have been unable to process this petition until now.

The Mexican bobcat belongs to the mammalian family Felidae and has been reported to be a subspecies of Lynx rufus. The number of taxa described within Lynx rufus ranges from 11 to 14. Allen (1903) first described this subspecies from two immature male specimens found in Escuinapa, Mexico, on the basis of color and cranial differences. However, the validity of this subspecies is questionable. Samson (1979) conducted a multivariate statistical analysis of a variety of skull measurements and found cranial characteristics of L. r. escuinapae to be similar to those of L. r. californicus and L. r. texensis. Also, the range of escuinapae overlaps with the ranges of baileyi and texensis. However, McCord and Cardoza (1982) noted that statistical analysis of skull measurements only have meaning in large samples and are thus ineffective in the subspecific assignment of individual specimens. They also noted that the 11 to 14 subspecies of bobcats described to date comprise few realistically distinguishable taxa that have any real biological or conservation significance.

The majority of bobcats are found in the United States, where they range through a wide variety of habitats, including boreal coniferous and mixed forests in the north, bottomland hardwood forest and coastal swamp in the southeast, and desert and scrubland in the southwest. Even within a local area, individual bobcats usually use a variety of habitats (Wilson and Ruff 1999). Only large, intensively cultivated areas appear to be unsuitable habitat. Southern Canada represents the northern limit of bobcat range, with deep snow a significant limiting factor. With the clearing of mature coniferous forests for agriculture, the bobcat has expanded its range northward over the past century (Rollings 1945, Banfield 1974). In Mexico, bobcats are found in dry scrubland and forest of pine (Pinus spp.) and oak (Quercus spp.), principally in the mountainous northern and central parts of the country, and not in the tropical south (Hall and Kelson 1959; Gonzalez and Leal 1984 and Woloszyn and Woloszyn 1982 cited by Nowell and Jackson 1996). Lynx rufus escuinapae is the southernmost race of bobcat found in Mexico.

No population estimates are available for Lynx rufus escuinapae, but the Mexican Government has stated that this subspecies is widespread and numerous, is not specialized in its habitat requirements, and is highly ecologically adaptable (Graciela de la Garza Garcia, Direccion General de Conservacion Ecologia de los Recursos Naturalese, in litt. 1991).

Little information is available on utilization of the species in Mexico, but local hunting and trapping for subsistence is possible. There is no indication of illegal trade and no reported potential trade threats (Govt. of U.S. 1992; Service, in litt. 1992).

We listed the Mexican bobcat as an endangered species on June 14, 1976 (41 FR 24064). This subspecies was listed under the Act due to its inclusion in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). By July 1, 1975, the Convention was ratified by enough nations to enter into force and at that time the countries participating in CITES agreed that the Mexican bobcat met the criteria for inclusion in Appendix I. Appendix I includes all species threatened with extinction and that are or may be affected by international trade. In 1992, during the 10-year review of species included in the CITES Appendices, we, with support from Mexico and other countries, proposed to transfer the Mexican bobcat to Appendix II, based on the bobcat's widespread and stable status in Mexico and questionable taxonomy. Our proposal was accepted and the transfer went into effect on November 6, 1992. It is not clear at this time why the Mexican bobcat was originally included in Appendix I.

Distinct Vertebrate Population Segment

We must consider any species for listing under the Act if available information indicates such action may be warranted. “Species” is defined by the Act as including any subspecies of fish and wildlife or plants, and any distinct population segment of vertebrate fish or wildlife that interbreeds when mature (16 U.S.C. 1532 (16)). We, along with the National Marine Fisheries Service (National Oceanic and Atmospheric Administration-Fisheries), developed the Policy Regarding the Recognition of Distinct Vertebrate Population Segments (DPS Policy) (61 FR 4722) to help us in determining what constitutes a distinct population segment (DPS). Under this policy, we use three elements to assess Start Printed Page 39592whether a population under consideration for listing may be recognized as a DPS: (1) Discreteness of the population in relation to the remainder of the species to which it belongs; (2) the significance of the population segment to the species to which it belongs; and (3) the population segment's conservation status in relation to the Act's standards for listing.

The DPS analysis is a stepwise analysis; significance is considered only when discreteness of the population has been determined, and the conservation status is considered only when both discreteness and significance of the population have been established. Discreteness refers to the isolation of a population from other members of the species and is based on two criteria: (1) Marked separation from other populations of the same taxon resulting from physical, physiological, ecological, or behavioral factors, including genetic discontinuity; or (2) populations delimited by international boundaries. If the population is determined to be discrete, we determine significance by assessing the distinct population segment's importance and/or contribution to the species throughout its range. Measures of significance may include, but are not limited to, the following: (1) Persistence of the discrete population segment in an ecological setting unusual or unique for the taxon; (2) evidence that loss of the discrete population segment would result in a significant gap in the range of the taxon; (3) evidence that the discrete population segment represents the only surviving natural occurrence of the taxon that may be more abundant elsewhere as an introduced population outside its historic range; and (4) evidence the discrete population segment differs markedly from other populations of the taxon in its genetic characteristics.

If we determine that a population meets the discreteness and significance criteria for a distinct population segment, we evaluate the threats to determine if endangered or threatened status based on the Act's standards is warranted. Endangered means the species is in danger of extinction throughout all or a significant portion of its range. Threatened means the species is likely to become endangered within the foreseeable future throughout all or a significant portion of its range.

In reviewing the taxonomic information on Mexican bobcat, it is unclear whether this subspecies is valid. If the subspecies designation is not valid, then we must evaluate the status of the listed entity in its range within Mexico and determine whether the listed entity meets the DPS policy, and if so, whether this population of bobcat should remain listed. Although the petition did not address this issue, we will consider this question during our status review.

Petition Finding

We have reviewed the petition, the literature cited in the petition, and other literature and information available in our files. On the basis of the best scientific and commercial information, we find that the petition presents substantial information to indicate that the Mexican bobcat may warrant being delisted.

With the publication of this notice, we are initiating a status review of the Mexican bobcat to determine whether delisting is warranted based on its status and taxonomy. If this subspecies is not taxonomically valid, we will also evaluate if the population of the listed entity in Mexico constitutes a DPS, and if so, whether or not we should retain the listing of this entity. If this population does not meet the DPS criteria, we will then evaluate whether or not the population of the listed entity is endangered or threatened in a significant portion of the species' (i.e., Lynx rufus) range.

Public Information Solicited

When we make a finding that sufficient information exists to indicate that delisting of a species may be warranted, we are required to promptly commence a review of the status of the species. To ensure that the status review is complete and based on the best available scientific and commercial information, we are soliciting information on the Mexican bobcat (Lynx rufus escuinapae) throughout the listed entity's range in Mexico. If we determine that the subspecies designation is not valid, then information on the status of the listed entity rangewide will, in particular, assist us in determining if the Mexican population meets the distinct vertebrate population segment criteria, or constitutes a significant portion of the range.

We request any additional information, comments, and suggestions from the public, governmental agencies, the scientific community, industry, and any other interested parties concerning the status of this subspecies of the bobcat throughout its range in Mexico. We are seeking information regarding taxonomy, historic and current distribution, habitat use and habitat conditions, biology and ecology, ongoing conservation measures for the subspecies and its habitat, and threats to the subspecies and its habitat. We are particularly interested in recent information on the taxonomy of the bobcat, and specifically whether escuinapae is a valid subspecies or whether it should be considered part of other subspecies. We also request any additional information that will support the DPS analysis of the discreteness and significance, as defined in our DPS policy (see Distinct Vertebrate Population Segment section above), of this Mexican population relative to the species as a whole.

If you wish to comment, you may submit your comments and materials concerning this finding to the Chief, Division of Scientific Authority (see ADDRESSES section). Our practice is to make comments, including names and home addresses of respondents, available for public review during regular office hours. Respondents may request that we withhold their identity, as allowable by law. If you wish us to withhold your name or address, you must state this request prominently at the beginning of your comment. However, we will not consider anonymous comments. To the extent consistent with applicable law, we will make all submissions from organizations or businesses, and from individuals identifying themselves as representatives or officials of organizations or businesses, available for public inspection in their entirety. Comments and materials received will be available for public inspection, by appointment, during normal business hours at the above address.

References Cited

Allen, J.A. 1903. A New Deer and a New Lynx From the State of Sinaloa, Mexico. Amer. Mus. Nat. Hist. Bull., 19:613-615.

Banfield, A.W. 1974. The Mammals of Canada. Univ. Toronto Press, Toronto.

Hall, E. R., and K. R. Kelson 1959. The Mammals of North America. The Ronald Press Company, New York.

Government of the United States. 1992. Proposal to Transfer Felis rufa escuinapae from Appendix I to Appendix II. Proc. Conf. of the Parties to CITES 8, CITES Secretariat, Lausanne.

Gonzalez, C.B., and C.G. Leal. 1984. [Forest Mammals of the Mexican Basin.] Programme on Man and the Biosphere (UNESCO) and Editorial Limusa. Mexico City (in Spanish).

McCord, C.M., and J.E. Cardoza. 1982. Bobcat and Lynx. Pp 728-766 in J.A. Chapman and G.A. Feldhamer, eds. Wild Mammals of North America: Biology, Management and Economics. Johns Hopkins Univ. Press, Baltimore. Start Printed Page 39593

Nowell, K., and P. Jackson. eds. 1996. Wild Cats: Status Survey and Conservation Action Plan. IUCN/SSC Cat Specialist Group, IUCN, Gland, Switzerland.

Rollings, C.T. 1945. Habits, Food and Parasites of the Bobcat in Minnesota. J. Wildl. Manage. 9:131-145.

Samson, F.B. 1979. Multivariate Analysis of Cranial Characteristics Among Bobcats with a Preliminary Discussion of the Number of Subspecies. Bobcat Res. Conf. Natl. Wildl. Fed. Sci. Tech. Ser. 6:80-86.

Wilson, D.E., and S. Ruff. eds. 1999. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington DC.

Woloszyn, D., and B.W. Woloszyn. 1982. [The Mammals of Sierra de La Laguna Baja California Sur.] Consejo Nacional de Ciencia y Technologia, Mexico (in Spanish).


The primary author of this document is Karen L. Anderson of the Division of Scientific Authority (see ADDRESSES above).


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

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Dated: June 11, 2003.

Marshall P. Jones, Jr.,

Deputy Director, Fish and Wildlife Service.

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[FR Doc. 03-16725 Filed 7-1-03; 8:45 am]