Species Ranking Status Codes
All of the species in the Animal Field Guide are categorized into several
groups based on their population and other factors. The Animal Field Guide
lists ranking codes of four different organizations.
Montana Species of Concern
The term “Species of Concern” includes taxa that are at-risk or potentially
at-risk due to rarity, restricted distribution, habitat loss, and/or other factors.
The term also encompasses species that have a special designation by organizations
or land management agencies in Montana, including: Bureau of Land Management
Special Status and Watch species; U.S. Forest Service Sensitive and Watch species;
U.S. Fish and Wildlife Service Threatened, Endangered and Candidate species.
Montana Species Ranking Codes
Montana employs a standardized
ranking system to denote global (G - range-wide) and state status (S)
(NatureServe 2003). Species are assigned numeric ranks ranging from 1
(critically imperiled) to 5 (demonstrably secure), reflecting the relative
degree to which they are “at-risk”. Rank definitions are given below. A number
of factors are considered in assigning ranks - the number, size and
distribution of known “occurrences” or populations, population trends (if known),
habitat sensitivity, and threat.
- G1 S1
- At high risk because of extremely limited and potentially declining
numbers, extent and/or habitat, making it highly vulnerable to global
extinction or extirpation in the state.
- G2 S2
- At risk because of very limited and potentially declining numbers,
extent and/or habitat, making it vulnerable to global extinction or
extirpation in the state.
- G3 S3
- Potentially at risk because of limited and potentially declining
numbers, extent and/or habitat, even though it may be abundant in
some areas.
- G4 S4
- Uncommon but not rare (although it may be rare in parts of its range),
and usually widespread. Apparently not vulnerable in most of its range,
but possibly cause for long-term concern.
- G5 S5
- Common, widespread, and abundant (although it may be rare in parts of
its range). Not vulnerable in most of its range.
Other Codes and Modifiers
- X
- Presumed Extinct - Species believed to be extinct throughout its range.
Not located despite intensive searches of historical sites and other
appropriate habitat, and virtually no likelihood that it will be
rediscovered.
- H
- Possibly Extinct - Species known from only historical occurrences,
but may nevertheless still be extant; further searching needed.
- U
- Unrankable - Species currently unrankable due to lack of information
or due to substantially conflicting information about status or trends.
- HYB
- Hybrid-Entity not ranked because it represents an interspecific hybrid and
not a species.
- T
- Infraspecific Taxon (trinomial) - The status of infraspecific taxa
(subspecies or varieties) are indicated by a “T-rank” following
the species’ global rank.
- ?
- Inexact Numeric Rank - Denotes inexact numeric rank
- Q
- Questionable taxonomy that may reduce conservation priority-Distinctiveness
of this entity as a taxon at the current level is questionable; resolution
of this uncertainty may result in change from a species to a subspecies or
hybrid, or inclusion of this taxon in another taxon, with the resulting
taxon having a lower-priority (numerically higher) conservation status rank.
- C
- Captive or Cultivated Only - Species at present is extant only in captivity
or cultivation, or as a reintroduced population not yet established.
- A
- Accidental - Species is accidental or casual in Montana, in other words,
infrequent and outside usual range. Includes species (usually birds
or butterflies) recorded once or only a few times at a location. A few
of these species may have bred on the one or two occasions they were recorded.
- Z
- Zero Occurrence - Species is present but lacking practical conservation concern
in Montana because there are no definable occurrences, although the taxon is
native and appears regularly in Montana.
- P
- Potential that species occurs in Montana but no extant or historic
occurrences are accepted.
- R
- Reported - Species reported in Montana but without a basis for
either accepting or rejecting the report, or the report not yet reviewed locally.
Some of these are very recent discoveries for which the program has not yet received
first-hand information; others are old, obscure reports.
- SYN
- Synonym - Species reported as occurring in Montana, but the Montana Natural Heritage
Program does not recognize the taxon; therefore the species is not assigned a rank.
- *
- A rank has been assigned and is under review. Contact the Montana Natural Heritage Program for assigned rank.
- B
- Breeding - Rank refers to the breeding population of the species in Montana.
- N
- Nonbreeding - Rank refers to the non-breeding population of the species in Montana.
U.S. Fish and Wildlife Service
- LE
- Listed endangered - Any species in danger of extinction
throughout all or a significant portion of its range (16 U.S.C. 1532(6))
- PE
- Proposed endangered - Any species for which a proposed rule has been
published in the Federal Register to list the species as endangered
- LT
- Listed threatened - Any species likely to become an endangered
species within the foreseeable future throughout all or a significant portion
of its range (16 U.S.C. 1532(20)).
- PT
- Proposed threatened - Any species for which a proposed rule has
been published in the Federal Register to list the species as threatened.
- E(S/A) or T(S/A)
- Any species listed endangered or threatened because of similarity of appearance.
- C
- Candidate - Those taxa for which sufficient information on
biological status and threats exists to propose to list them as threatened
or endangered. We encourage their consideration in environmental planning
and partnerships; however, none of the substantive or procedural provisions
of the Act apply to candidate species.
- PDL
- Proposed for delisting - Any species for which a final rule has
been published in the Federal Register to delist the species.
- NL
- Not listed - No designation.
- XE
- Essential experimental population - An experimental population
whose loss would be likely to appreciably reduce the likelihood of the survival
of the species in the wild
- XN
- Nonessential experimental population - An experimental population
of a listed species reintroduced into a specific area that receives more flexible
management under the Act.
- CH
- Critical Habitat - The specific areas (i) within the geographic
area occupied by a species, at the time it is listed, on which are found those
physical or biological features (I) essential to conserve the species and (II)
that may require special management considerations or protection; and (ii)
specific areas outside the geographic area occupied by the species at the time
it is listed upon determination that such areas are essential to conserve the species.
- 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, that has a record in the database has USESA status, but the entire
species does not.
- PS:value
- Partial status - status in only a portion of the species’ range.
The value of that status appears in parentheses because the entity with status
is not recognized as a valid taxon by Central Sciences (usually a population
defined by geopolitical boundaries or defined administratively, such as
experimental populations.
- none
- Usually indicates 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 refresh of this website, some taxa may have a
status that does not yet appear.
Forest Service
The status of species on Forest Service lands as defined by the U.S. Forest Service
manual (2670.22). These taxa are listed as such by the Regional Forester (Northern
Region). The Forest Service lists animal species as:
- Endangered
- Listed as Endangered (LE) by the USFWS.
- Threatened
- Listed as Threatened (LT) by the USFWS.
- Sensitive
- Any species for which the Regional Forester has determined there is a concern
for population viability within the state, as evidenced by a significant
current or predicted downward trend in populations or habitat.
- Watch
- Any species recognized by Forest Supervisors that are either not known to
occur on national forest land but predicted to occur there on the basis of
suitable habitat, or known to occur on national forest land but with no
immediate or predicted threats to population viability.
Bureau of Land Management
The status of species on Bureau of Land Management Lands as defined by the
BLM 6840 Manual; designated by the Montana State Office of the BLM in 1996.
- Special Status / Sensitive
- Any species proven to be imperiled in at least part of its range and
documented to occur on BLM lands.
- Watch
- Any species either known to be imperiled and suspected to occur on BLM
lands; suspected to be imperiled and documented on BLM lands; or needing
further study for other reasons.
