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CRITERIA FOR CRITICALLY ENDANGERED, ENDANGERED AND
VULNERABLE
CRITICALLY ENDANGERED (CR)
A taxon is Critically Endangered when the best available evidence indicates
that it meets any of the following criteria (A to E), and it is therefore considered to be facing an extremely high risk of
extinction in the wild:
A. Reduction in population size based on any of the following:
1. An observed,
estimated, inferred or suspected population size reduction of 90% over the last
10 years or three generations, whichever
is the longer, where the causes of the reduction are clearly
reversible AND understood AND ceased, based on (and specifying)
any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline
in area of occupancy, extent of occurrence and/or quality of habitat
(d) actual or potential levels of exploitation
(e)
the effects of introduced taxa, hybridization, pathogens, pollutants, competitors
or parasites.
2. An observed,
estimated, inferred or suspected population size reduction of 80% over the
last 10 years or three generations, whichever
is the longer, where the reduction or its causes
may not have ceased OR may not be understood OR may not be reversible,
based on (and specifying)
any of (a) to (e) under A1.
3. A population size reduction of 80%, projected or suspected
to be met within the next 10
years or three generations, whichever is the longer (up to a maximum of 100 years), based
on
(and specifying) any of (b) to (e) under A1.
4. An observed, estimated, inferred, projected or suspected population
size reduction of
80% over any 10 year or three generation period, whichever is longer (up to a maximum of 100 years
in
the future), where the time period must include both the past and the future, and where the reduction
or its causes
may not have ceased OR may not be understood OR may not be reversible, based on
(and specifying) any of (a) to (e) under
A1.
B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:
1.
Extent of occurrence estimated to be less than 100 km˛, and estimates indicating at least two of a-c:
a. Severely
fragmented or known to exist at only a single location.
b. Continuing decline, observed, inferred or projected, in
any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality of
habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations
in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) number of locations or subpopulations
(iv) number of mature individuals.
2. Area of occupancy estimated to be less than 10 km˛, and estimates indicating
at least two of a-c:
a. Severely fragmented or known to exist at only a single location.
b. Continuing decline,
observed, inferred or projected, in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii)
area, extent and/or quality of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii)
number of locations or subpopulations
(iv) number of mature individuals.
C. Population size estimated to number fewer
than 250 mature individuals and either:
1. An estimated continuing decline of at least 25% within three years
or one generation, whichever is
longer, (up to a maximum of 100 years in the future) OR
2. A continuing decline,
observed, projected, or inferred, in numbers of mature individuals AND at least
one of the following (a-b):
(a)
Population structure in the form of one of the following:
(i) no subpopulation estimated to contain more than 50 mature
individuals, OR
(ii) at least 90% of mature individuals in one subpopulation.
(b) Extreme fluctuations in number
of mature individuals.
D. Population size estimated to number fewer than 50 mature individuals.
E. Quantitative
analysis showing the probability of extinction in the wild is at least 50% within 10 years or three generations, whichever
is the longer (up to a maximum of 100 years).
ENDANGERED (EN)
A taxon is Endangered when the best available evidence
indicates that it meets any of the following criteria (A to E), and it is therefore considered to be facing a very high risk
of extinction in the wild:
A. Reduction in population size based on any of the following:
1. An observed,
estimated, inferred or suspected population size reduction of 70% over the last 10 years
or three generations, whichever
is the longer, where the causes of the reduction are clearly reversible
AND understood AND ceased, based on (and specifying)
any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline
in area of occupancy, extent of occurrence and/or quality of habitat
(d) actual or potential levels of exploitation
(e)
the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
2. An observed, estimated,
inferred or suspected population size reduction of 50% over the last 10 years
or three generations, whichever is the
longer, where the reduction or its causes may not have
ceased OR may not be understood OR may not be reversible, based
on (and specifying) any of (a)
to (e) under A1.
3. A population size reduction of 50%, projected or suspected
to be met within the next 10 years
or three generations, whichever is the longer (up to a maximum of 100 years), based
on (and specifying)
any of (b) to (e) under A1.
4. An observed, estimated, inferred, projected or suspected population
size reduction of 50% over any 10
year or three generation period, whichever is longer (up to a maximum of 100 years
in the future),
where the time period must include both the past and the future, and where the reduction or its
causes
may not have ceased OR may not be understood OR may not be reversible, based on (and
specifying) any of (a) to (e) under
A1.
B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:
1.
Extent of occurrence estimated to be less than 5000 km˛, and estimates indicating at least two of a-c:
a. Severely
fragmented or known to exist at no more than five locations.
b. Continuing decline, observed, inferred or projected,
in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality
of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations
in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) number of locations or subpopulations
(iv) number of mature individuals.
2. Area of occupancy estimated to be less than 500 km˛, and estimates indicating
at least two of a-c:
a. Severely fragmented or known to exist at no more than five locations.
b. Continuing
decline, observed, inferred or projected, in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
C. Extreme fluctuations in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii)
number of locations or subpopulations
(iv) number of mature individuals.
C. Population size estimated to number fewer
than 2500 mature individuals and either:
1. An estimated continuing decline of at least 20% within five years
or two generations, whichever is
longer, (up to a maximum of 100 years in the future) OR
2. A continuing decline,
observed, projected, or inferred, in numbers of mature individuals AND at least one
of the following (a-b):
(a)
Population structure in the form of one of the following:
(i) no subpopulation estimated to contain more than 250 mature
individuals, OR
(ii) at least 95% of mature individuals in one subpopulation.
(b) Extreme fluctuations in number
of mature individuals.
D. Population size estimated to number fewer than 250 mature individuals.
E. Quantitative
analysis showing the probability of extinction in the wild is at least 20% within 20 years or five generations, whichever
is the longer (up to a maximum of 100 years).
VULNERABLE (VU)
A taxon is Vulnerable when the best available
evidence indicates that it meets any of the following criteria (A to E), and it is therefore considered to be facing a high
risk of extinction in the wild:
A. Reduction in population size based on any of the following:
1. An observed,
estimated, inferred or suspected population size reduction of 50% over the last 10 years
or three generations, whichever
is the longer, where the causes of the reduction are: clearly reversible
AND understood AND ceased, based on (and specifying)
any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline
in area of occupancy, extent of occurrence and/or quality of habitat
(d) actual or potential levels of exploitation
(e)
the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
2. An observed, estimated,
inferred or suspected population size reduction of 30% over the last 10 years
or three generations, whichever is the
longer, where the reduction or its causes may not
have ceased OR may not be understood OR may not be reversible, based
on (and specifying)
any of (a) to (e) under A1.
3. A population size reduction of 30%, projected or suspected
to be met within the next 10 years
or three generations, whichever is the longer (up to a maximum of 100 years), based
on (and
specifying) any of (b) to (e) under A1.
4. An observed, estimated, inferred, projected or suspected population
size reduction of 30% over any 10
year or three generation period, whichever is longer (up to a maximum of 100 years
in the future), where
the time period must include both the past and the future, and where the reduction or its causes
may not
have ceased OR may not be understood OR may not be reversible, based on (and specifying) any of (a) to
(e)
under A1.
B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:
1.
Extent of occurrence estimated to be less than 20,000 km˛, and estimates indicating at least
two of a-c:
a. Severely
fragmented or known to exist at no more than 10 locations.
b. Continuing decline, observed, inferred or projected,
in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality
of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations
in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) number of locations or subpopulations
(iv) number of mature individuals.
2. Area of occupancy estimated to be less than 2000 km˛, and estimates indicating
at least two of a-c:
a. Severely fragmented or known to exist at no more than 10 locations.
b. Continuing
decline, observed, inferred or projected, in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii) area, extent and/or quality of habitat
(iv) number of locations or subpopulations
(v) number of mature individuals.
c. Extreme fluctuations in any of the following:
(i) extent of occurrence
(ii) area of occupancy
(iii)
number of locations or subpopulations
(iv) number of mature individuals.
C. Population size estimated to number fewer
than 10,000 mature individuals and either:
1. An estimated continuing decline of at least 10% within 10 years
or three generations, whichever is
longer, (up to a maximum of 100 years in the future) OR
2. A continuing decline,
observed, projected, or inferred, in numbers of mature individuals AND at least
one of the following (a-b):
(a)
Population structure in the form of one of the following:
(i) no subpopulation estimated to contain more than 1000 mature
individuals, OR
(ii) all mature individuals are in one subpopulation.
(b) Extreme fluctuations in number of mature
individuals.
D. Population very small or restricted in the form of either of the following:
1. Population
size estimated to number fewer than 1000 mature individuals.
2. Population with a very restricted area of occupancy
(typically less than 20 km˛) or number of locations
(typically five or fewer) such that it is prone to the effects of
human activities or
stochastic events within a very short time period in an uncertain future, and is thus capable
of
becoming Critically Endangered or even Extinct in a very short time period.
E. Quantitative analysis showing the probability
of extinction in the wild is at least 10% within 100 years.
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