The Secretary may add a species to the lists or designate critical habitat, delete a species or critical habitat, change the listed status of a species, revise the boundary of an area designated as critical habitat, or adopt or modify special rules (see 50 CFR 17.40-17.48 and parts 222 and 227) applied to a threatened species only in accordance with the procedures of this part.

(a) Any species or taxonomic group of species (e.g., genus, subgenus) as defined in § 424.02 is eligible for listing under the Act. A taxon of higher rank than species may be listed only if all included species are individually found to be endangered or threatened. In determining whether a particular taxon or population is a species for the purposes of the Act, the Secretary shall rely on standard taxonomic distinctions and the biological expertise of the Department and the scientific community concerning the relevant taxonomic group.

(b) The Secretary shall make any determination required by paragraphs (c), (d), and (e) of this section solely on the basis of the best available scientific and commercial information regarding a species' status without reference to possible economic or other impacts of such determination.

(c) A species shall be listed or reclassified if the Secretary determines, on the basis of the best scientific and commercial data available after conducting a review of the species' status, that the species meets the definition of an endangered species or a threatened species because of any one or a combination of the following factors:

(1) The present or threatened destruction, modification, or curtailment of its habitat or range;

(2) Overutilization for commercial, recreational, scientific, or educational purposes;

(3) Disease or predation;

(4) The inadequacy of existing regulatory mechanisms; or

(5) Other natural or manmade factors affecting its continued existence.

(d) In determining whether a species is a threatened species, the Services must analyze whether the species is likely to become an endangered species within the foreseeable future. The foreseeable future extends as far into the future as the Services can make reasonably reliable predictions about the threats to the species and the species' responses to those threats. The Services will describe the foreseeable future on a case-by-case basis, using the best available data and taking into account considerations such as the species' life-history characteristics, threat-projection timeframes, and environmental variability. The Services need not identify the foreseeable future in terms of a specific period of time.

(e) Species will be delisted if the Secretary determines, based on consideration of the factors and standards set forth in paragraph (c) of this section, that the best scientific and commercial data available substantiate that:

(1) The species is extinct;

(2) The species has recovered to the point at which it no longer meets the definition of an endangered species or a threatened species;

(3) New information that has become available since the original listing decision shows the listed entity does not meet the definition of an endangered species or a threatened species; or

(4) New information that has become available since the original listing decision shows the listed entity does not meet the definition of a species.

(f) The fact that a species of fish, wildlife, or plant is protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (see part 23 of this title) or a similar international agreement on such species, or has been identified as requiring protection from unrestricted commerce by any foreign nation, or to be in danger of extinction or likely to become so within the foreseeable future by any State agency or by any agency of a foreign nation that is responsible for the conservation of fish, wildlife, or plants, may constitute evidence that the species is endangered or threatened. The weight given such evidence will vary depending on the international agreement in question, the criteria pursuant to which the species is eligible for protection under such authorities, and the degree of protection afforded the species. The Secretary shall give consideration to any species protected under such an international agreement, or by any State or foreign nation, to determine whether the species is endangered or threatened.

(g) The Secretary shall take into account, in making determinations under paragraph (c) or (e) of this section, those efforts, if any, being made by any State or foreign nation, or any political subdivision of a State or foreign nation, to protect such species, whether by predator control, protection of habitat and food supply, or other conservation practices, within any area under its jurisdiction, or on the high seas.

(a) To the maximum extent prudent and determinable, we will propose and finalize critical habitat designations concurrent with issuing proposed and final listing rules, respectively. If designation of critical habitat is not prudent or if critical habitat is not determinable, the Secretary will state the reasons for not designating critical habitat in the publication of proposed and final rules listing a species. The Secretary will make a final designation of critical habitat on the basis of the best scientific data available, after taking into consideration the probable economic, national security, and other relevant impacts of making such a designation in accordance with § 424.19.

(1) Designation of critical habitat may not be prudent in circumstances such as, but not limited to, the following:

(i) The species is threatened by taking or other human activity and identification of critical habitat can be expected to increase the degree of such threat to the species;

(ii) The present or threatened destruction, modification, or curtailment of a species' habitat or range is not a threat to the species;

(iii) Areas within the jurisdiction of the United States provide no more than negligible conservation value, if any, for a species occurring primarily outside the jurisdiction of the United States; or

(iv) No areas meet the definition of critical habitat.

(2) Designation of critical habitat is not determinable when one or both of the following situations exist:

(i) Data sufficient to perform required analyses are lacking; or

(ii) The biological needs of the species are not sufficiently well known to identify any area that meets the definition of “critical habitat.”

(b) Where designation of critical habitat is prudent and determinable, the Secretary will identify specific areas within the geographical area occupied by the species at the time of listing and any specific areas outside the geographical area occupied by the species to be considered for designation as critical habitat.

(1) The Secretary will identify, at a scale determined by the Secretary to be appropriate, specific areas within the geographical area occupied by the species for consideration as critical habitat. The Secretary will:

(i) Identify the geographical area occupied by the species at the time of listing.

(ii) Identify physical and biological features essential to the conservation of the species at an appropriate level of specificity using the best available scientific data. This analysis will vary between species and may include consideration of the appropriate quality, quantity, and spatial and temporal arrangements of such features in the context of the life history, status, and conservation needs of the species.

(iii) Determine the specific areas within the geographical area occupied by the species that contain the physical or biological features essential to the conservation of the species.

(iv) Determine which of these features may require special management considerations or protection.

(2) After identifying areas occupied by the species at the time of listing, the Secretary will identify, at a scale determined by the Secretary to be appropriate, specific areas outside the geographical area occupied by the species at the time of listing that the Secretary determines are essential for the conservation of the species. Such a determination must be based on the best scientific data available.

(c) Each critical habitat area will be shown on a map, with more-detailed information discussed in the preamble of the rulemaking documents published in the Federal Register and made available from the lead field office of the Service responsible for such designation. Textual information may be included for purposes of clarifying or refining the location and boundaries of each area or to explain the exclusion of sites (e.g., paved roads, buildings) within the mapped area. Each area will be referenced to the State(s), county(ies), or other local government units within which all or part of the critical habitat is located. Unless otherwise indicated within the critical habitat descriptions, the names of the State(s) and county(ies) are provided for informational purposes only and do not constitute the boundaries of the area. Ephemeral reference points (e.g., trees, sand bars) shall not be used in any textual description used to clarify or refine the boundaries of critical habitat.

(d) When several habitats, each satisfying the requirements for designation as critical habitat, are located in proximity to one another, the Secretary may designate an inclusive area as critical habitat.

(e) The Secretary may designate critical habitat for those species listed as threatened or endangered but for which no critical habitat has been previously designated. For species listed prior to November 10, 1978, the designation of critical habitat is at the discretion of the Secretary.

(f) The Secretary may revise existing designations of critical habitat according to procedures in this section as new data become available.

(g) The Secretary will not designate critical habitat within foreign countries or in other areas outside of the jurisdiction of the United States.

(h) The Secretary will not designate as critical habitat land or other geographic areas owned or controlled by the Department of Defense, or designated for its use, that are subject to a compliant or operational integrated natural resources management plan (INRMP) prepared under section 101 of the Sikes Act (16 U.S.C. 670a) if the Secretary determines in writing that such plan provides a conservation benefit to the species for which critical habitat is being designated. In determining whether such a benefit is provided, the Secretary will consider:

(1) The extent of the area and features present;

(2) The type and frequency of use of the area by the species;

(3) The relevant elements of the INRMP in terms of management objectives, activities covered, and best management practices, and the certainty that the relevant elements will be implemented; and

(4) The degree to which the relevant elements of the INRMP will protect the habitat from the types of effects that would be addressed through a destruction-or-adverse-modification analysis.

When considering any revision of the lists, the Secretary shall consult as appropriate with affected States, interested persons and organizations, other affected Federal agencies, and, in cooperation with the Secretary of State, with the country or countries in which the species concerned are normally found or whose citizens harvest such species from the high seas. Data reviewed by the Secretary may include, but are not limited to scientific or commercial publications, administrative reports, maps or other graphic materials, information received from experts on the subject, and comments from interested parties.

(a) Ability to petition. Any interested person may submit a written petition to the Services requesting that one of the actions described in § 424.10 be taken for a species.

(b) Notification of intent to file petition. For a petition to list, delist, or reclassify a species, or for petitions to revise critical habitat, petitioners must provide notice to the State agency responsible for the management and conservation of fish, plant, or wildlife resources in each State where the species that is the subject of the petition occurs. This notification must be made at least 30 days prior to submission of the petition. This notification requirement shall not apply to any petition submitted pertaining to a species that does not occur within the United States.

(c) Requirements for petitions. A petition must clearly identify itself as such, be dated, and contain the following information:

(1) The name, signature, address, telephone number, if any, and the association, institution, or business affiliation, if any, of the petitioner;

(2) The scientific name and any common name of a species of fish or wildlife or plants that is the subject of the petition. Only one species may be the subject of a petition, which may include, by hierarchical extension based on taxonomy and the Act, any subspecies or variety, or (for vertebrates) any potential distinct population segments of that species;

(3) A clear indication of the administrative action the petitioner seeks (e.g., listing of a species or revision of critical habitat);

(4) A detailed narrative justifying the recommended administrative action that contains an analysis of the information presented;

(5) Literature citations that are specific enough for the Services to readily locate the information cited in the petition, including page numbers or chapters as applicable;

(6) Electronic or hard copies of supporting materials, to the extent permitted by U.S. copyright law, or appropriate excerpts or quotations from those materials (e.g., publications, maps, reports, letters from authorities) cited in the petition;

(7) For a petition to list, delist, or reclassify a species, information to establish whether the subject entity is a “species” as defined in the Act;

(8) For a petition to list a species, or for a petition to delist or reclassify a species in cases where the species' range has changed since listing, information on the current and historical geographic range of the species, including the States or countries intersected, in whole or part, by that range; and

(9) For a petition to list, delist or reclassify a species, or for petitions to revise critical habitat, copies of the notification letters or electronic communication which petitioners provided to the State agency or agencies responsible for the management and conservation of fish, plant, or wildlife resources in each State where the species that is the subject of the petition currently occurs.

(d) Information to be included in petitions to add or remove species from the lists, or change the listed status of a species. The Service's determination as to whether the petition provides substantial scientific or commercial information indicating that the petitioned action may be warranted will depend in part on the degree to which the petition includes the following types of information:

(1) Information on current population status and trends and estimates of current population sizes and distributions, both in captivity and the wild, if available;

(2) Identification of the factors under section 4(a)(1) of the Act that may affect the species and where these factors are acting upon the species;

(3) Whether and to what extent any or all of the factors alone or in combination identified in section 4(a)(1) of the Act may cause the species to be an endangered species or threatened species (i.e., the species is currently in danger of extinction or is likely to become so within the foreseeable future), and, if so, how high in magnitude and how imminent the threats to the species and its habitat are;

(4) Information on adequacy of regulatory protections and effectiveness of conservation activities by States as well as other parties, that have been initiated or that are ongoing, that may protect the species or its habitat; and

(5) A complete, balanced representation of the relevant facts, including information that may contradict claims in the petition.

(e) Information to be included in petitions to revise critical habitat. The Services' determinations as to whether the petition provides substantial scientific information indicating that the petitioned action may be warranted will depend in part on the degree to which the petition includes the following types of information:

(1) A description and map(s) of areas that the current designation does not include that should be included, or includes that should no longer be included, and a description of the benefits of designating or not designating these specific areas as critical habitat. Petitioners should include sufficient supporting information to substantiate the requested changes, which may include GIS data or boundary layers that relate to the request, if appropriate;

(2) A description of physical or biological features essential for the conservation of the species and whether they may require special management considerations or protection;

(3) For any areas petitioned to be added to critical habitat within the geographical area occupied by the species at time it was listed, information indicating that the specific areas contain one or more of the physical or biological features (including characteristics that support ephemeral or dynamic habitat conditions) that are essential to the conservation of the species and may require special management considerations or protection. The petitioner should also indicate which specific areas contain which features;

(4) For any areas petitioned for removal from currently designated critical habitat within the geographical area occupied by the species at the time it was listed, information indicating that the specific areas do not contain the physical or biological features (including characteristics that support ephemeral or dynamic habitat conditions) that are essential to the conservation of the species, or that these features do not require special management considerations or protection;

(5) For areas petitioned to be added to or removed from critical habitat that were outside the geographical area occupied by the species at the time it was listed, information indicating why the petitioned areas are or are not essential for the conservation of the species; and

(6) A complete, balanced representation of the relevant facts, including information that may contradict claims in the petition.

(f) Response to petitions. (1) If a request does not meet the requirements set forth at paragraph (c) of this section, the Services will generally reject the request without making a finding, and will, within a reasonable timeframe, notify the sender and provide an explanation of the rejection. However, the Services retain discretion to process a petition where the Services determine there has been substantial compliance with the relevant requirements.

(2) If a request does meet the requirements set forth at paragraph (c) of this section, the Services will acknowledge receipt of the petition by posting information on the respective Service's Web site.

(g) Supplemental information. If the petitioner provides supplemental information before the initial finding is made and states that it is part of the petition, the new information, along with the previously submitted information, is treated as a new petition that supersedes the original petition, and the statutory timeframes will begin when such supplemental information is received.

(h) Findings on petitions to add or remove a species from the lists, or change the listed status of a species. (1) To the maximum extent practicable, within 90 days of receiving a petition to add a species to the lists, remove a species from the lists, or change the listed status of a species, the Services will make a finding as to whether the petition presents substantial scientific or commercial information indicating that the petitioned action may be warranted. The Services will publish the finding in the Federal Register.

(i) For the purposes of this section, “substantial scientific or commercial information” refers to credible scientific or commercial information in support of the petition's claims such that a reasonable person conducting an impartial scientific review would conclude that the action proposed in the petition may be warranted. Conclusions drawn in the petition without the support of credible scientific or commercial information will not be considered “substantial information.”

(ii) In reaching the initial finding on the petition, the Services will consider the information referenced at paragraphs (c), (d), and (g) of this section. The Services may also consider information readily available at the time the determination is made. The Services are not required to consider any supporting materials cited by the petitioner if the cited document is not provided in accordance with paragraph (c)(6) of this section.

(iii) The “substantial scientific or commercial information” standard must be applied in light of any prior reviews or findings the Services have made on the listing status of the species that is the subject of the petition. Where the Services have already conducted a finding on, or review of, the listing status of that species (whether in response to a petition or on the Services' own initiative), the Services will evaluate any petition received thereafter seeking to list, delist, or reclassify that species to determine whether a reasonable person conducting an impartial scientific review would conclude that the action proposed in the petition may be warranted despite the previous review or finding. Where the prior review resulted in a final agency action, a petitioned action generally would not be considered to present substantial scientific and commercial information indicating that the action may be warranted unless the petition provides new information not previously considered.

(2) If the Services find that a petition presents substantial information indicating that the petitioned action may be warranted, the Services will commence a review of the status of the species concerned. At the conclusion of the status review and within 12 months of receipt of the petition, the Services will make one of the following findings:

(i) The petitioned action is not warranted, in which case the Service shall publish a finding in the Federal Register.

(ii) The petitioned action is warranted, in which case the Services shall publish in the Federal Register a proposed regulation to implement the action pursuant to § 424.16; or

(iii) The petitioned action is warranted, but:

(A) The immediate proposal and timely promulgation of a regulation to implement the petitioned action is precluded because of other pending proposals to list, delist, or change the listed status of species; and

(B) Expeditious progress is being made to list, delist, or change the listed status of qualified species, in which case such finding will be published in the Federal Register together with a description and evaluation of the reasons and data on which the finding is based. The Secretary will make any determination of expeditious progress in relation to the amount of funds available after complying with nondiscretionary duties under section 4 of the Act and court orders and court-approved settlement agreements to take actions pursuant to section 4 of the Act.

(3) If a finding is made under paragraph (h)(2)(iii) of this section with regard to any petition, the Services will, within 12 months of such finding, again make one of the findings described in paragraph (h)(2) of this section with regard to such petition.

(i) Findings on petitions to revise critical habitat. (1) To the maximum extent practicable, within 90 days of receiving a petition to revise a critical habitat designation, the Services will make a finding as to whether the petition presents substantial scientific information indicating that the revision may be warranted. The Services will publish such finding in the Federal Register.

(i) For the purposes of this section, “substantial scientific information” refers to credible scientific information in support of the petition's claims such that a reasonable person conducting an impartial scientific review would conclude that the revision proposed in the petition may be warranted. Conclusions drawn in the petition without the support of credible scientific information will not be considered “substantial information.”

(ii) The Services will consider the information referenced at paragraphs (c), (e), and (g) of this section. The Services may also consider other information readily available at the time the determination is made in reaching its initial finding on the petition. The Services are not required to consider any supporting materials cited by the petitioner if the cited documents are not provided in accordance with paragraph (b)(6) of this section.

(2) If the Services find that the petition presents substantial information that the requested revision may be warranted, the Services will determine, within 12 months of receiving the petition, how to proceed with the requested revision, and will promptly publish notice of such intention in the Federal Register. That notice may, but need not, take a form similar to one of the findings described under paragraph (h)(2) of this section.

(j) Petitions to designate critical habitat or adopt rules under sections 4(d), 4(e), or 10(j) of the Act. The Services will conduct a review of petitions to designate critical habitat or to adopt a rule under section 4(d), 4(e), or 10(j) of the Act in accordance with the Administrative Procedure Act (5 U.S.C. 553) and applicable Departmental regulations, and take appropriate action.

(k) Withdrawal of petition. A petitioner may withdraw the petition at any time during the petition process by submitting such request in writing. If a petition is withdrawn, the Services may, at their discretion, discontinue action on the petition finding, even if the Services have already made a 90-day finding that there is substantial information indicating that the requested action may be warranted.

(a) If the Secretary finds that one of the actions described in § 424.10 may be warranted, but that the available evidence is not sufficiently definitive to justify proposing the action at that time, a notice of review may be published in the Federal Register. The notice will describe the measure under consideration, briefly explain the reasons for considering the action, and solicit comments and additional information on the action under consideration.

(b) The Secretary from time to time also may publish notices of review containing the names of species that are considered to be candidates for listing under the Act and indicating whether sufficient scientific or commercial information is then available to warrant proposing to list such species, the names of species no longer being considered for listing, or the names of listed species being considered for delisting or reclassification. However, none of the substantive or procedural provisions of the Act apply to a species that is designated as a candidate for listing.

(c) Such notices of review will invite comment from all interested parties regarding the status of the species named. At the time of publication of such a notice, notification in writing will be sent to State agencies in any affected States, known affected Federal agencies, and, to the greatest extent practicable, through the Secretary of State, to the governments of any foreign countries in which the subject species normally occur.

(a) General. Based on the information received through §§ 424.13, 424.14, 424.15, and 424.21, or through other available avenues, the Secretary may propose revising the lists as described in § 424.10.

(b) Contents. A notice of a proposed rule to carry out one of the actions described in § 424.10 will contain a detailed description of the proposed action and a summary of the data on which the proposal is based (including, as appropriate, citation of pertinent information sources) and will show the relationship of such data to the rule proposed. If such a rule proposes to designate or revise critical habitat, such summary will, to the maximum extent practicable, include a brief description and evaluation of those activities (whether public or private) that, in the opinion of the Secretary, if undertaken, may adversely modify such habitat or may be affected by such designation. For any proposed rule to designate or revise critical habitat, the detailed description of the action will include a map of the critical habitat area, and may also include rule text that clarifies or modifies the map. Any such notice proposing the listing, delisting, or reclassification of a species or the designation or revision of critical habitat will also include a summary of factors affecting the species and/or its designated critical habitat.

(c) Procedures—(1) Notifications. In the case of any proposed rule to list, delist, or reclassify a species, or to designate or revise critical habitat, the Secretary shall—

(i) Publish notice of the proposal in the Federal Register;

(ii) Give actual notice of the proposed regulation to the State agency in each State in which the species is believed to occur and to each county or equivalent jurisdiction therein in which the species is believed to occur, and invite the comment of each such agency and jurisdiction;

(iii) Give notice of the proposed regulation to any Federal agencies, local authorities, or private individuals or organizations known to be affected by the rule;

(iv) Insofar as practical, and in cooperation with the Secretary of State, give notice of the proposed regulation to list, delist, or reclassify a species to each foreign nation in which the species is believed to occur or whose citizens harvest the species on the high seas, and invite the comment of such nation;

(v) Give notice of the proposed regulation to such professional scientific organizations as the Secretary deems appropriate; and

(vi) Publish a summary of the proposed regulation in a newspaper of general circulation in each area of the United States in which the species is believed to occur.

(2) Period of public comments. At least 60 days shall be allowed for public comment following publication in the Federal Register of a rule proposing the listing, delisting, or reclassification of a species, or the designation or revision of critical habitat. All other proposed rules shall be subject to a comment period of at least 30 days following publication in the Federal Register. The Secretary may extend or reopen the period for public comment on a proposed rule upon a finding that there is good cause to do so. A notice of any such extension or reopening shall be published in the Federal Register, and shall specify the basis for so doing.

(3) Public hearings. The Secretary shall promptly hold at least one public hearing if any person so requests within 45 days of publication of a proposed regulation to list, delist, or reclassify a species, or to designate or revise critical habitat. Notice of the location and time of any such hearing shall be published in the Federal Register not less than 15 days before the hearing is held.

(a) General. (1) Within 1 year of the publication of a rule proposing to determine whether a species is an endangered or threatened species, or to designate or revise critical habitat, the Secretary shall publish one of the following in the Federal Register:

(i) A final rule to implement such determination or revision,

(ii) A finding that such revision should not be made,

(iii) A notice withdrawing the proposed rule upon a finding that available evidence does not justify the action proposed by the rule, or

(iv) A notice extending such 1-year period by an additional period of not more than 6 months because there is substantial disagreement among scientists knowledgeable about the species concerned regarding the sufficiency or accuracy of the available data relevant to the determination or revision concerned.

(2) If an extension is made under paragraph (a)(1)(iv) of this section, the Secretary shall, within the extended period, take one of the actions described in paragraphs (a)(1) (i), (ii), or (iii) of this section.

(3) If a proposed rule is withdrawn under paragraph (a)(1)(iii) of this section, the notice of withdrawal shall set forth the basis upon which the proposed rule has been found not to be supported by available evidence. The Secretary shall not again propose a rule withdrawn under such provision except on the basis of sufficient new information that warrants a reproposal.

(b) Critical habitat designations. A final rule designating critical habitat of an endangered or a threatened species shall to the extent permissible under § 424.12 be published concurrently with the final rule listing such species, unless the Secretary deems that—

(1) It is essential to the conservation of such species that it be listed promptly; or

(2) Critical habitat of such species is not then determinable,

(a) Contents. A final rule promulgated to carry out the purposes of the Act will be published in the Federal Register. This publication will contain a detailed description of the action being finalized, a summary of the comments and recommendations received in response to the proposal (including applicable public hearings), summaries of the data on which the rule is based and the relationship of such data to the final rule, and a description of any conservation measures available under the rule. Publication of a final rule to list, delist, or reclassify a species or designate or revise critical habitat will also provide a summary of factors affecting the species.

(1) For a rule designating or revising critical habitat, the detailed description of the action will include a map of the critical habitat area, and may also include rule text that clarifies or modifies the map. The map itself, as modified by any rule text, constitutes the official boundary of the designation.

(i) The Service responsible for the designation will include more-detailed information in the preamble of the rulemaking document and will make the coordinates and/or plot points on which the map is based available to the public on the Internet site of the Service promulgating the designation, at www.regulations.gov, and at the lead field office of the Service responsible for the designation.

(ii) In addition, if the Service responsible for the designation concludes that additional tools or supporting information would be appropriate and would help the public understand the official boundary map, it will, for the convenience of the public, make those additional tools and supporting information available on our Internet sites and at the lead field office of the Service that is responsible for the critical habitat designation (and may also include it in the preamble and/or at www.regulations.gov).

(2) The rule will, to the maximum extent practicable, include a brief description and evaluation of those activities (whether public or private) that might occur in the area and which, in the opinion of the Secretary, may adversely modify such habitat or be affected by such designation.

(b) Effective date. A final rule shall take effect—

(1) Not less than 30 days after it is published in the Federal Register, except as otherwise provided for good cause found and published with the rule; and

(2) Not less than 90 days after (i) publication in the Federal Register of the proposed rule, and (ii) actual notification of any affected State agencies and counties or equivalent jurisdictions in accordance with § 424.16(c)(1)(ii).

(c) Disagreement with State agency. If a State agency, given notice of a proposed rule in accordance with § 424.16(c)(1)(ii), submits comments disagreeing in whole or in part with a proposed rule, and the Secretary issues a final rule that is in conflict with such comments, or if the Secretary fails to adopt a regulation for which a State agency has made a petition in accordance with § 424.14, the Secretary shall provide such agency with a written justification for the failure to adopt a rule consistent with the agency's comments or petition.

(a) At the time of publication of a proposed rule to designate critical habitat, the Secretary will make available for public comment the draft economic analysis of the designation. The draft economic analysis will be summarized in the Federal Register notice of the proposed designation of critical habitat.

(b) Prior to finalizing the designation of critical habitat, the Secretary will consider the probable economic, national security, and other relevant impacts of the designation upon proposed or ongoing activities. The Secretary will consider impacts at a scale that the Secretary determines to be appropriate, and will compare the impacts with and without the designation. Impacts may be qualitatively or quantitatively described.

(c) The Secretary has discretion to exclude any particular area from the critical habitat upon a determination that the benefits of such exclusion outweigh the benefits of specifying the particular area as part of the critical habitat. In identifying those benefits, in addition to the mandatory consideration of impacts conducted pursuant to paragraph (b) of this section, the Secretary may assign the weight given to any benefits relevant to the designation of critical habitat. The Secretary, however, will not exclude any particular area if, based on the best scientific and commercial data available, the Secretary determines that the failure to designate that area as critical habitat will result in the extinction of the species concerned.

(a) Sections 424.16, 424.17, 424.18, and 424.19 notwithstanding, the Secretary may at any time issue a regulation implementing any action described in § 424.10 in regard to any emergency posing a significant risk to the well-being of a species of fish, wildlife, or plant. Such rules shall, at the discretion of the Secretary, take effect immediately on publication in the Federal Register. In the case of any such action that applies to a resident species, the Secretary shall give actual notice of such regulation to the State agency in each State in which such species is believed to occur. Publication in the Federal Register of such an emergency rule shall provide detailed reasons why the rule is necessary. An emergency rule shall cease to have force and effect after 240 days unless the procedures described in §§ 424.16, 424.17, 424.18, and 424.19 (as appropriate) have been complied with during that period.

(b) If at any time after issuing an emergency rule, the Secretary determines, on the basis of the best scientific and commercial data available, that substantial evidence does not then exist to warrant such rule, it shall be withdrawn.

At least once every 5 years, the Secretary shall conduct a review of each listed species to determine whether it should be delisted or reclassified. Each such determination shall be made in accordance with §§ 424.11, 424.16, and 424.17 of this part, as appropriate. A notice announcing those species under active review will be published in the Federal Register. Notwithstanding this section's provisions, the Secretary may review the status of any species at any time based upon a petition (see § 424.14) or upon other data available to the Service.