Explanation of Endangered Species Rankings

Explanation of Ranking Categories Employed by Natural Heritage Programs Nationwide

Each element is assigned a single global rank as well as a state rank for each state in which it occurs. Global ranking is done under the guidance of NatureServe, Arlington, VA. State ranks are assigned by each state’s Natural Heritage Program, thus a rank for a particular element may vary considerably from state to state. Federal ranks are designated by the U.S. Fish & Wildlife Service under the provisions of the Endangered Species Act of 1973. DISCLAIMER: This document is not an official copy of the laws in effect and should not be utilized or relied upon as such. For this reason, the accuracy of the information contained within this document cannot be guaranteed and the reader is cautioned that it is his/her responsibility to be apprised of the laws in effect at any given time. These laws include those contained within the Louisiana Revised Statutes, particularly Title 56, the official regulations of the Louisiana Wildlife and Fisheries Commission, federal laws, and any local or parish ordinances.

Federal Ranks (USESA FIELD):

  •  LE = Listed Endangered
  •  LT = Listed Threatened
  •  PE = Proposed endangered
  •  PT = Proposed Threatened
  •  C = Candidate
  •  PDL = Proposed for delisting
  •  E (S/A) or T (S/A) = Listed endangered or threatened because of similarity of appearance
  •  XE = Essential experimental population
  •  XN = Nonessential experimental population
  •  No Rank = Usually indicates that the taxon does not have any federal status. However, because of potential lag time between publication in the Federal Register and entry in the central databases and state databases, some taxa may have a status which does not yet appear.
  •  (Rank, Rank) = Combination values in parenthesis = The taxon itself is not named in the Federal Register as having U.S. ESA status; however, all of its infraspecific taxa (worldwide) do have official status. The statuses shown in parentheses indicate the statuses that apply to infraspecific taxa or populations within this taxon. THE SPECIES IS CONSIDERED TO HAVE A COMBINATION STATUS IN LOUISIANA
  •  (PS) = partial status= Status in only a portion of the species’ range. Typically indicated in a “full” species record where an infraspecific taxon or population has U.S. ESA status, but the entire species does not. THE SPECIES DOES NOT HAVE A STATUS IN LOUISIANA
  •  (PS: Rank) = partial status= Status in only a portion of the species’ range. The value of that status appears because the entity with status does not have an individual entry in Natureserve. THE SPECIES MAY HAVE A STATUS IN LOUISIANA

Global Element Ranks:

  •  G1 = critically imperiled globally because of extreme rarity (5 or fewer known extant populations) or because of some factor(s) making it especially vulnerable to extinction
  •  G2 = imperiled globally because of rarity (6 to 20 known extant populations) or because of some factor(s) making it very vulnerable to extinction throughout its range 
  •  G3 = either very rare and local throughout its range or found locally (even abundantly at some of its locations) in a restricted range (e.g., a single physiographic region) or because of other factors making it vulnerable to extinction throughout its range (21 to 100 known extant populations)
  •  G4 = apparently secure globally, though it may be quite rare in parts of its range, especially at the periphery (100 to 1000 known extant populations)
  •  G5 = demonstrably secure globally, although it may be quite rare in parts of its range, especially at the periphery (1000+ known extant populations)
  •  GH = of historical occurrence throughout its range; i.e., formerly part of the established biota, with the possibility that it may be rediscovered (e.g., Bachman’s Warbler)
  •  GU = possibly in peril range-wide, but status uncertain; need more information
  •  G? = rank uncertain. Or a range (e.g., G3G5) delineates the limits of uncertainty
  •  GQ = uncertain taxonomic status
  •  GX = believed to be extinct throughout its range (e.g., Passenger Pigeon) with virtually no likelihood that it will be rediscovered
  •  T = subspecies or variety rank (e.g., G5T4 applies to a subspecies with a global species rank of G5, but with a subspecies rank of G4)

State Element Ranks:

  •  S1 = critically imperiled in Louisiana because of extreme rarity (5 or fewer known extant populations) or because of some factor(s) making it especially vulnerable to extirpation
  •  S2 = imperiled in Louisiana because of rarity (6 to 20 known extant populations) or because of some factor(s) making it very vulnerable to extirpation
  •  S3 = rare and local throughout the state or found locally (even abundantly at some of its locations) in a restricted region of the state, or because of other factors making it vulnerable to extirpation (21 to 100 known extant populations)
  •  S4 = apparently secure in Louisiana with many occurrences (100 to 1000 known extant populations)
  •  S5 = demonstrably secure in Louisiana (1000+ known extant populations)
    (B or N may be used as qualifier of numeric ranks and indicating whether the occurrence is breeding or nonbreeding)
  •  SA = accidental in Louisiana, including species (usually birds or butterflies) recorded once or twice or only at great intervals hundreds or even thousands of miles outside their usual range
  •  SH = of historical occurrence in Louisiana, but no recent records verified within the last 20 years; formerly part of the established biota, possibly still persisting
  •  SR = reported from Louisiana, but without conclusive evidence to accept or reject the report
  •  SU = possibly in peril in Louisiana, but status uncertain; need more information
  •  SX = believed to be extirpated from Louisiana
  •  SZ = transient species in which no specific consistent area of occurrence is identifiable

State Protection Status:

State status are contained in Title 56 of the Louisiana Revised Statutes as well as relevant rules and regulations adopted by the Louisiana Wildlife and Fisheries Commission and the Secretary of the Department of Wildlife and Fisheries. The Secretary of the Department of Wildlife and Fisheries is authorized to implement additional restrictions in emergency situations in order to protect fish and wildlife resources.

  •  Endangered = Taking or harassment of these species is a violation of state and federal laws.
  •  Threatened = Taking or harassment of these species is a violation of state and federal laws.
  •  Threatened/Endangered = Taking or harassment of these species is a violation of state and federal laws.
  •  Prohibited = Possession of these species is prohibited. No legal harvest or possession.
  •  Restricted Harvest = There are restrictions regarding the taking and possession of these species.