the iucn red list categories and criteria are
TRANSCRIPT
IUCN (International Union for Conservation of Nature)
Introduction to the IUCN Red Listing Process
IUCN (International Union for Conservation of Nature)
The IUCN Red List assessment estimates risk of extinctionrisk of extinction
What is the likelihood of a species becomingextinct in the near future, given current knowledge about population trends, range, and recent, current or projected threats?
IUCN (International Union for Conservation of Nature)
The IUCN Red List Categories &
CriteriaAll materials are freely available on IUCN Red List web site:
www.iucnredlist.org
IUCN (International Union for Conservation of Nature)
Scope of Application
• All described taxa (species, subspecies, varieties), except micro-organisms• Taxa not yet formally described, but only if they are:
• A clearly distinct species;• Museum/herbarium voucher references are provided;• Distribution information is available;• There is clear conservation benefit to assessing the species.
IUCN Categories and Criteria can be applied to:
The IUCN Red List Categories and Criteria are:• Used to assess taxa at the global level• Can be used at regional levels (but see the Guidelines for Application of
IUCN Red List Criteria at Regional Levels)• Used to assess wild populations inside their natural range (including
populations resulting from benign introductions)
IUCN (International Union for Conservation of Nature)
CR A2ace;B1ab(iii)
Category: Critically Endangered
Rabb’s Fringe-limbed TreefrogRabb’s Fringe-limbed Treefrog Ecnomiohyla rabborumEcnomiohyla rabborum
Criteria & subcriteria
IUCN (International Union for Conservation of Nature)
The IUCN
Categories
Not Evaluated (NE)
Near Threatened (NT)
Data Deficient (DD)
Endangered (EN)
Critically Endangered (CR)
Vulnerable (VU)
Extinct in the Wild (EW)
Extinct (EX)
Least Concern (LC)
IUCN (International Union for Conservation of Nature)
A taxon is Extinct when there is no reasonable doubt that the last individual has died.
Dodo, Raphus cucullatus
Extinct (EX)
Extinct in the Wild (EW)
A taxon is Extinct in the Wild when it is known only to survive in cultivation, in captivity or as a naturalized population (or populations) well outside the past range.
Franklinia, Franklinia alatamaha
Photo © Craig Hilton-Taylor
IUCN (International Union for Conservation of Nature)
A taxon is threatened when the best available evidence indicates that it meets any of the criteria A to E for the thresholds stated in one of the three threatened categories: Critically Endangered, Endangered or Vulnerable.
Critically Endangered (CR)
CR taxa are considered to be facing an extremely high risk of extinction in the wild
Mandrinette, Hibiscus fragilis
Photo © Wendy Strahm
Endangered (EN)
EN taxa are considered to be facing a very high risk of extinction in the wild
Black-browed Albatross, Thalassarche melanophrys
Photo © Tony Palliser
Vulnerable (VU)
VU taxa are considered to be facing a high risk of extinction in the wild
Golden Pagoda, Mimetes
chrysanthusPhoto © Craig Hilton-
Taylor
IUCN (International Union for Conservation of Nature)
Near Threatened (NT)
A taxon is Near Threatened when it has been evaluated against the criteria and does not qualify for CR, EN or VU now, but is close to qualifying for or is likely to qualify for a threatened category in the near future.
Macaronesian Laurel, Laurus azoricaPhoto © H. Fraga
Least Concern (LC)
A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for CR, EN, VU or NT. Widespread and abundant taxa are included in this category.
Olive Baboon, Papio anumbisPhoto © Caroline Pollock
IUCN (International Union for Conservation of Nature)
Data Deficient (DD)
A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status.
Tree TomatoSolanum [Cyphomandra] betacea
Not Evaluated (NE)
A taxon is Not Evaluated when it has not yet been evaluated against the criteria
IUCN (International Union for Conservation of Nature)
Although DD and NE are not threatened categories, taxa classed as DD or NE should NOT be treated as not threatened
Data Deficient (DD)
Not Evaluated (NE)
IUCN (International Union for Conservation of Nature)
Types of data required for IUCN Red List assessments
IUCN (International Union for Conservation of Nature)
Dealing with a lack of high quality data
• The threatened categories use quantitative thresholds
• BUT a lack of high quality data should not deter assessors from applying the IUCN criteria.
IUCN (International Union for Conservation of Nature)
Acceptable types of data qualityObservedObserved
Projected Projected
EstimatedEstimated
InferredInferred
SuspectedSuspected
IUCN (International Union for Conservation of Nature)
ObservedObserved
Observed information is directly based on well-documented observations of all known individuals in the population.
EstimatedEstimated
Estimated information is based on calculations that may involve assumptions and/or interpolations in time (in the past).
Projected Projected Projected information is the same as “estimated”, but the variable of interest is extrapolated in time towards the future
IUCN (International Union for Conservation of Nature)
Inferred Inferred
Inferred information is based on variables that are indirectly related to the variable of interest, but in the same general type of units (e.g. number of individuals or area or number of subpopulations).
SuspectedSuspected
Suspected information is based on circumstantial evidence, or on variables in different types of units. In general, this can be based on any factor related to population abundance or distribution.
IUCN (International Union for Conservation of Nature)
Uncertainty in the data itself (different to the lack of data) has to be considered in a Red List assessment
Dealing with data uncertainty
Handling uncertainty has a strong influence on evaluations.
• If uncertainty leads to a wide variation in the results, the range of possible outcomes should be recorded
• A single category must be chosen and the basis for the decision should be documented, and should be both precautionary and credible
• When data are very uncertain, the category of 'Data Deficient' may be assigned, based on the data being inadequate rather than the taxon being poorly known
IUCN (International Union for Conservation of Nature)
Concepts and definitions underlying the IUCN Red List
Categories and Criteria
IUCN (International Union for Conservation of Nature)
Key terms used in the IUCN Red List criteria
Population and Population SizePopulation and Population SizeSubpopulationsSubpopulationsMature IndividualsMature IndividualsGeneration LengthGeneration LengthReductionReductionContinuing DeclineContinuing Decline
IUCN (International Union for Conservation of Nature)
Extreme FluctuationsExtreme FluctuationsSeverely FragmentedSeverely FragmentedExtent of OccurrenceExtent of OccurrenceArea of OccupancyArea of OccupancyLocationLocationQuantitative AnalysisQuantitative Analysis
Key terms used in the IUCN Red List criteria
IUCN (International Union for Conservation of Nature)
Population is the total number of individuals of a given taxon across its across its global range.global range.Population size is measured as the number of mature individuals only.
Population and Population SizePopulation and Population Size
SubpopulationsSubpopulationsSubpopulations are geographically or otherwise distinct groups in the population between which there is little demographic exchange (e.g., 1 successful migrant individual or gamete per year).
Mature IndividualsMature IndividualsMature Individuals are individuals that are known, estimated or inferred to be capable of reproduction.
IUCN (International Union for Conservation of Nature)
Population SizePopulation Size(mature individuals only)(mature individuals only)
SubpopulationsSubpopulations
PopulationPopulation
IUCN (International Union for Conservation of Nature)
Generation LengthGeneration Length
Generation Length is the average age of parents of the current cohort (i.e., newborn individuals in the population).
• Greater than the age at first breeding and less than the oldest breeding individual, except in taxa that breed only once.
• Reflects turnover rate of breeding individuals in a population.• Scales all time-based measurements in the criteria to account for
different rates at which taxa survive and reproduce.• Where generation length varies under threat, use the more natural (i.e.
pre-disturbance) generation length.
IUCN (International Union for Conservation of Nature)
ReductionReduction
Reduction is a decline in population size of at least the % stated in criterion A over the specified time period.
Time
Population Size
Continuing DeclineContinuing Decline
Continuing Decline is a recent, current or projected future decline which is liable to continue unless remedial measures are taken.
IUCN (International Union for Conservation of Nature)
Extreme FluctuationsExtreme Fluctuations
Extreme Fluctuations occur in a number of taxa where population size or distribution area varies widely, rapidly and frequently, typically with a variation greater than one order of magnitude (i.e., a tenfold increase of decrease).
IUCN (International Union for Conservation of Nature)
0
5,000
10,000
15,000
20,000
25,000
Jan '02 July '02 Jan '03 July '03 Jan '04 July '04 Jan '05 July '05 Jan '06 July '06
Natural seasonal fluctuations – flux of individuals between different life stages. Not real changes in total
population size, therefore not extreme fluctuation
Extreme FluctuationsExtreme Fluctuations
IUCN (International Union for Conservation of Nature)
0
5,000
10,000
15,000
20,000
25,000
Jan '02 July '02 Jan '03 July '03 Jan '04 July '04 Jan '05 July '05 Jan '06 July '06
Extreme FluctuationsExtreme Fluctuations
Natural seasonal fluctuations, with threatening events also causing very large population size variations during reproductive
seasons (e.g., dormant eggs/seeds damaged or lost). Real changes in total population size, therefore extreme fluctuation
IUCN (International Union for Conservation of Nature)
Severely FragmentedSeverely Fragmented
Severely Fragmented refers to the situation in which increased extinction risks to the taxon result from the fact that most of its individuals are found in relatively isolated subpopulations.
IUCN (International Union for Conservation of Nature)
The existence of small and isolated habitat patches alone is not enough to consider a taxon to be severely fragmented – there should also be knowledge about the taxon’s dispersal ability.
Severely FragmentedSeverely Fragmented
Taxa with highly mobile adult stages or producing large numbers of small, mobile diaspores can disperse more easily and are not so vulnerable to isolation through fragmented habitats.
Taxa producing small numbers of diaspores (or none at all), or only large ones are less able to disperse over wide areas and are more easily isolated.
IUCN (International Union for Conservation of Nature)
Extent of Occurrence is the area contained within the shortest continuous imaginary boundary which can be drawn to encompass all known, inferred, or projected sites presently occupied by the taxon.
Area of Occupancy is the area within the extent of occurrence which is actually occupied by the taxon (measured by overlaying a grid and counting number of occupied cells).
Extent of OccurrenceExtent of Occurrence
Area of OccupancyArea of Occupancy
IUCN (International Union for Conservation of Nature)
Extent of OccurrenceExtent of Occurrence
Comparison of taxa with same AOO but different EOO – a single threatening event is more likely to rapidly have a major impact on the taxon with the smaller EOO than the taxon with the larger EOO:
AOO = 10x4 = 40 km2
EOO = 44 km²
AOO = 10x4 = 40 km2
EOO = 105 km²
Threatening Threatening eventevent
IUCN (International Union for Conservation of Nature)
Extent of OccurrenceExtent of Occurrence
Comparison of taxa with same AOO but different EOO – a single threatening event is more likely to rapidly have a major impact on the taxon with the smaller EOO than the taxon with the larger EOO:
AOO = 7x4 = 28 km2
EOO = 28 km²
AOO = 8x4 = 32 km2
EOO = 82 km²
One major threatening event caused:
20% decline in AOO, 22% decline in EOO, <20% decline in population size
One major threatening event caused:
30% decline in AOO, 36% decline in EOO, >39% decline in population size
IUCN (International Union for Conservation of Nature)
Problems of Scale
AOO = 10 x 1 = 10 units2AOO = 3 x 16 = 48 units2
Grid Cells 16 units² Grid Cell = 1 unit²
Area of OccupancyArea of Occupancy
In many cases, a grid size of 2 km (i.e., cell area 4 km²) is an appropriate scale.
IUCN (International Union for Conservation of Nature)
LocationLocation
Location is a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon.
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LocationLocation
2 locations
Invasive species
IUCN (International Union for Conservation of Nature)
LocationLocation
4 locations
Pollution
IUCN (International Union for Conservation of Nature)
LocationLocation
4-5 locations
Pollution
IUCN (International Union for Conservation of Nature)
Quantitative AnalysisQuantitative Analysis
Quantitative Analysis is any form of analysis which estimates the extinction probability of a taxon based on known life history, habitat requirements, threats and any specified management options (e.g., Population Viability Analysis (PVA)).
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IUCN (International Union for Conservation of Nature)
The IUCN Red List Criteria
IUCN (International Union for Conservation of Nature)
A Population reduction
B Restricted geographic range
C Small population size & decline
Very small or restricted populationD
E Quantitative analysis
CRITERIA
Quantitative thresholds
THREATENED CATEGORIES
Critically Endangered (CR)
Endangered (EN)
Vulnerable (VU)
Nature of the Criteria
IUCN (International Union for Conservation of Nature)
Why use multiple criteria?
• All taxa being assessed must be evaluated against each criterion.
• Meeting any one of the criteria qualifies a taxon for listing at that level of threat
• All criteria met at the highest level of threat should be listed.
Not all the criteria are appropriate to all taxa.
IUCN (International Union for Conservation of Nature)
IUCN (International Union for Conservation of Nature)
Time
Population Size
Criterion APast, present or future population reduction
IUCN (International Union for Conservation of Nature)
Based on any of four criteria:
A1: Population reduction in past and causes of decline now ceased
A2: Population reduction in past and causes of decline ongoing
A3: Population reduction expected in future
A4: Population reduction in past AND future
Criterion A
IUCN (International Union for Conservation of Nature)
Criterion A1past reduction & causes understood & ceased & reduction is reversible
Last 10 years or 3 generations (whichever is longer)
90% Critically Endangered90% Critically Endangered 70% Endangered70% Endangered
50% Vulnerable50% Vulnerable
Present
Criterion A2past reduction & causes may not be understood or may not have ceased or reduction may not be reversible 80% Critically 80% Critically
EndangeredEndangered
50% Endangered50% Endangered
30% Vulnerable30% Vulnerable
Last 10 years or 3 generations (whichever is longer)
Present
IUCN (International Union for Conservation of Nature)
50%50% Endangered Endangered
Next 10 years or 3 generations(whichever is longer up to a maximum of 100
years)
80% 80% Critically Critically EndangeredEndangered
30% 30% VulnerableVulnerable
Present
Sub-criterion A3future decline
Sub-criterion A4past & future
80% 80% Critically EndangeredCritically Endangered
50%50% Endangered Endangered
30% 30% VulnerableVulnerable
Present
10 years or 3 generations(whichever is longer, up to a maximim of 100 years in the future)
including some time in the past AND in the future
IUCN (International Union for Conservation of Nature)
10 years / 3 generations
6.6 years / 2 generations
3.3 years / 1 generation
6.6 years / 2 generations
3.3 years / 1 generation
10 years / 3 generations
Sub-criterion A4past & future: “shifting time window”
Present
5 years / 1.5 generations
5 years / 1.5 generations
10 years / 3 generations
IUCN (International Union for Conservation of Nature)
For ALL the criteria (A1–A4), rate of population reduction should be based on any of:
(a) Direct observation (not for sub-criterion A3 – future reduction)
(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• parasites
IUCN (International Union for Conservation of Nature)
A. A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1A1 90% 70% 50%
A2, A3 & A4A2, A3 & A4 80% 50% 30%
A1A1. . Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a)(a) direct observation direct observation(b)(b) an index of abundance appropriate to the taxon an index of abundance appropriate to the taxon(c)(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality(d)(d) actual or potential levels of exploitation actual or potential levels of exploitation(e)(e) Effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites Effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites
A2A2. . Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A3A3. . Population reduction projected or suspected to be met in the future (up to a maximum of 100 years), based on (b) to (e) under A1.
A4A4. . An observed, estimated, inferred, An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
Use any of the criteria A-EUse any of the criteria A-E Critically EndangeredCritically Endangered EndangeredEndangered VulnerableVulnerable
IUCN (International Union for Conservation of Nature)
Points to remember: • Reduction in population size may be a one-off event, or may be
continuing.
• Sub-criterion A1 has higher thresholds than the other sub-criteria.
• For sub-criterion A1, causes of population decline must be understood AND must have ceased AND the reduction is the reduction is reversible.
• Sub-criterion A3 based on declines projected into the FUTURE, therefore it cannot be based on direct observation.
• Sub-criterion A4 (the “shifting time window”) must include some time in the past AND some time in the future.
• All time measurements are based on ten years OR 3 generations whichever is the longer time period (100 year time cap in future).
Criterion A
IUCN (International Union for Conservation of Nature)
Criterion BRestricted geographic range and
fragmentation, continuing decline or extreme fluctuations
IUCN (International Union for Conservation of Nature)
Based on either of two sub-criteria:B1: Estimated extent of occurrence
AND / OR
B2: Estimated area of occupancy
Criterion B
AND at least TWO of a-c:a. Severely fragmented or few locations
b. Continuing decline
c. Extreme fluctuations
IUCN (International Union for Conservation of Nature)
Criterion B
Subcriterion B1
Extent of occurrence estimated to be:
EN
VU
< 100 km²< 100 km²
< 20,000 km²< 20,000 km²
< 5,000 km²< 5,000 km²
Subcriterion B2
Area of occupancy estimated to be:
CR < 10 km²< 10 km²
< 500 km²< 500 km²
< 2,000 km²< 2,000 km²
IUCN (International Union for Conservation of Nature)
Criterion B
a. Severely fragmented or # locations:
EN
VU 10
55
11CR
AND at least TWO of a, b or c:
b. Continuing decline in any of the following:
(i) EOO
(ii) AOO
(iii)Area, extent and/or quality of habitat
(iv) # locations or subpopulations
(v) # mature individuals
c. Extreme fluctuation in any of the following:
(i) EOO
(ii) AOO
(iii) # locations or subpopulations
(iv) # mature individuals
IUCN (International Union for Conservation of Nature)
Use any of the criteria A-EUse any of the criteria A-E Critically EndangeredCritically Endangered EndangeredEndangered VulnerableVulnerable
B. B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1B1. Extent of occurrence. Extent of occurrence < 100 km²< 100 km² < 5,000 km²< 5,000 km² < 20,000 km²< 20,000 km²
B2B2. Area of occupancy. Area of occupancy < 10 km²< 10 km² < 500 km²< 500 km² < 2,000 km²< 2,000 km²
AND at least 2 of the followingAND at least 2 of the following
(a) (a) Severely fragmented, Severely fragmented, OROR
Number of locationsNumber of locations = 1= 1 ≤≤ 55 ≤ ≤ 1010
(b)(b) Continuing decline in any of: Continuing decline in any of: (i)(i) extent of occurrence; extent of occurrence; (ii)(ii) area of occupancy; area of occupancy; (iii)(iii) area, extent and/or quality of area, extent and/or quality of habitat; habitat; (iv)(iv) number of locations or subpopulations; number of locations or subpopulations; (v)(v) number of mature individuals number of mature individuals
(c)(c) Extreme fluctuations in any of: Extreme fluctuations in any of: (i)(i) extent of occurrence; extent of occurrence; (ii)(ii) area of occupancy; area of occupancy; (iii)(iii) number of locations or number of locations or subpopulations; subpopulations; (iv)(iv) number of mature individuals number of mature individuals
IUCN (International Union for Conservation of Nature)
Points to remember: • Subcriterion B1 is based on extent of occurrence, while subcriterion
B2 is based on area of occupancy.
• Either subcriteria B1 or B2, or both may apply.
• To fully qualify for a listing under criterion B, the taxon must meet at least two of the subcriteria a, b or c.
• Subcriterion B1a / B2a may be based on either severe fragmentation OR number of locations – please remember the definitions of these terms when applying them.
Criterion B
IUCN (International Union for Conservation of Nature)
Small population size and continuing decline
Extinct
Criterion C
IUCN (International Union for Conservation of Nature)
Based on small population size AND either C1 or C2:
Criterion C
C1: Continuing decline in population size at a specified rate
OR
C2: Continuing decline in population size at any, unspecified rate AND either C2a or C2b:C2a: (i) very small subpopulations, OR (ii) most mature
individuals are in one subpopulation
C2b: extreme fluctuations in number of mature individuals
IUCN (International Union for Conservation of Nature)
Criterion C
Thresholds for criterion C
Population size is estimated at:
EN
VU
< 250 mature individuals< 250 mature individualsCR
< 2,500 mature individuals< 2,500 mature individuals
< 10,000 mature individuals< 10,000 mature individuals
IUCN (International Union for Conservation of Nature)
Criterion C
Subcriterion C1Estimated continuing decline of:
EN
VU
25% within 3 years or 1 25% within 3 years or 1 generationgeneration
CR
20% within 5 years or 2 20% within 5 years or 2 generationsgenerations
10% within 10 years or 3 10% within 10 years or 3 generationsgenerations
IUCN (International Union for Conservation of Nature)
Criterion C
Subcriterion C2Observed, projected or inferred continuing decline at any rate
EN
VU
< 50 mature < 50 mature individualsindividuals
CR
< 250 mature < 250 mature individualsindividuals
< 1,000 mature < 1,000 mature individualsindividuals
AND at least one of the following:
C2a(i).
All subpopulations have:
90% of the 90% of the mature mature
individualsindividuals
95% of the 95% of the mature mature
individualsindividuals
100% of the 100% of the mature mature
individualsindividuals
C2a(ii).
One subpopulation contains:
C2b.
There are extreme fluctuations in number of mature individuals.
IUCN (International Union for Conservation of Nature)
Use any of the criteria A-EUse any of the criteria A-E Critically EndangeredCritically Endangered EndangeredEndangered VulnerableVulnerable
C. C. Small population size and decline
Number of mature individualsNumber of mature individuals < 250< 250 < 2,500< 2,500 < 10,000< 10,000
AND either C1 or C2AND either C1 or C2::
C1. C1. An estimated continuing An estimated continuing decline of at least:decline of at least:
25% in 3 years or 1 25% in 3 years or 1 generationgeneration
20% in 5 years or 2 20% in 5 years or 2 generationsgenerations
10% in 10 years or 3 10% in 10 years or 3 generationsgenerations
(b)(b) extreme fluctuations in the number of mature individuals extreme fluctuations in the number of mature individuals
(up to a maximum of 100 years in future)(up to a maximum of 100 years in future)
C2.C2. A continuing decline A continuing decline ANDAND (a) and/or (b): (a) and/or (b):
(a i) (a i) number of mature number of mature individuals in each individuals in each subpopulation:subpopulation:
< 50< 50 < 250< 250 < 1,000< 1,000
(a ii)(a ii) or % individuals in one or % individuals in one subpopulation =subpopulation =
90-100%90-100% 95-100%95-100% 100%100%
IUCN (International Union for Conservation of Nature)
Points to remember: • The population size threshold must be met before considering the
thresholds for subcriteria C1 or C2.
• Subcriterion C1 is based on continuing decline at a specified rate and over a very specific time period.
• Subcriterion C2 is based on continuing decline at any, unspecified rate, but the taxon must also meet the requirements for subcriteria C2a or C2b.
Criterion C
IUCN (International Union for Conservation of Nature)
Very small or restricted populationCriterion D
IUCN (International Union for Conservation of Nature)
Criterion D
Criterion D is split into D for the CR and EN categories; and D1 and D2 for the VU category.
EN
VU
< 50 mature individuals
CR
< 250 mature individuals
< 1,000 mature individuals
D. Total current population size estimated as:
D1. Total current population size estimated as:
D2. The population has a very restricted AOO (typically <20 km²) or is known from very few locations (typically ≤5).
NOTE: for the VU D2, there should be a plausible threat that is likely to rapidly affect the population.
IUCN (International Union for Conservation of Nature)
Use any of the criteria A-EUse any of the criteria A-E Critically EndangeredCritically Endangered EndangeredEndangered VulnerableVulnerable
D. Very small or restricted populationEither:
Number of mature Number of mature individualsindividuals < 50< 50 < 250< 250 D1. D1. < 1,000< 1,000
AND / ORAND / OR
D2.D2. typically: typically:
AOO < 20 km² or AOO < 20 km² or number of locations number of locations ≤ 5 5
VU D2. Restricted area of occupancy or number of locations with a plausible future threat that could drive the taxon to CR or EX in a very short time.
IUCN (International Union for Conservation of Nature)
Points to remember: • Criterion D has population size thresholds that apply to categories CR
and EN only.
• Subcriteria D1 and D2 apply to the VU category only.
• Subcriterion D2 should be used when a population has a very restricted range such that it is prone to the effects of human activities or stochastic events within a very short time period.
• When using subcriterion D2, the most serious plausible threat to the species should be stated in the assessment.
• In subcriterion D2, the values for AOO and number of locations are given as examples only.
Criterion D
IUCN (International Union for Conservation of Nature)
Quantitative analysis
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Criterion E
IUCN (International Union for Conservation of Nature)
Based on quantitative analysis showing a probability of extinction in the wild is at least:
Within 10 years or 3 generations
Within 20 years or 5 generations
Within 100 years
50%
Critically Endangered
10%Vulnerable
20%
Endangered
Up to a maximum of 100 years in the future
Criterion E
IUCN (International Union for Conservation of Nature)
Use any of the criteria A-EUse any of the criteria A-E Critically EndangeredCritically Endangered EndangeredEndangered VulnerableVulnerable
E. Quantitative analysis
Indicating the probability of Indicating the probability of extinction in the wild to be:extinction in the wild to be:
50% in 10 years or 3 generations (100 years
max)
20% in 20 years or 5 generations (100 years
max)
10% in 100
IUCN (International Union for Conservation of Nature)
• All species in the Red List have supporting documentation.• Justifies the selected category and criteria.• Allows analysis of Red List data (information coded using
standard Classification Schemes).
RED LIST DOCUMENTATION
• Taxonomy including authority details.• Common names• Red List Category and Criteria• Countries of occurrence• Map of distribution• Rationale for the assessment
(supporting the criteria used)
• Names of assessors• Habitat preferences (text & codes)• Major Threats (text and codes)• Conservation Measures in place &
needed (text and codes)• Trade and Use• Citations list• Reasons for any category changes
IUCN (International Union for Conservation of Nature)
Case Study 1Case Study 1
Taylor’s Salamander Taylor’s Salamander Ambystoma taylori Ambystoma taylori (Brandon, Maruska & Rumph, 1981) (Brandon, Maruska & Rumph, 1981)
IUCN (International Union for Conservation of Nature)
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
TaxonomyBased on both allozymes and mtDNA, this is a very distinctive salamander. The Ambystoma salamanders occurring in other natural lakes around Alchichica are not closely related to this species.
RangeTaylor’s salamander is endemic to Lake Alchichica, a saline crater lake located in eastern Puebla, Mexico, at 2,290 m above sea level. The Ambystoma salamanders occurring in the other natural lakes around Alchichica are not closely related to this species. The surface area of the lake is 2.3 km².
IUCN (International Union for Conservation of Nature)
PopulationEven at its only known locality this is a rare species, although formerly it was common there. Divers deep in the lake have seen the species recently.
Habitat & EcologyThis salamander usually does not metamorphose, and most individuals live permanently in water. But, occasional individuals have been known to metamorphose. It breeds in the lake, and is usually found in very deep water, often more than 30 m below the surface.
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
ThreatsThe most serious threat to the species is water extraction and diversion resulting in the lake becoming even more saline. The water level has dropped many meters over the last two decades. Continued transformation and pollution of the lake is likely to result in the disappearance of this species. Attempts to introduce fish in the lake have failed because of its salinity.
Conservation MeasuresTaylor’s salamander does not occur in any protected area. Captive breeding may be an essential short-term measure to save this species, if it is not too late. The protection of the Alchichica lake is an urgent priority. This species is protected under the category Pr (Special protection) by the Government of Mexico.
IUCN (International Union for Conservation of Nature)
Is the taxon eligible for Red List assessment?
• Description of the species has been published (Brandon, Maruska & Rumph, 1981).
YES
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
• The species was formerly common and is now rare.
• BUT, no indication of the time period over which a presumed decline has taken place or data to be able to estimate the scale of population decline.
NO
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
Can criterion A be applied?(Population reduction at a specific rate over 10 years or 3 generations
(whichever is longer) in the past, present, and/or future)
IUCN (International Union for Conservation of Nature)YES – CR B1ab(iii,v)+2ab(iii,v)
• The total lake area = 2.3 km² therefore the Critically Endangered thresholds for extent of occurrence (<100 km²) and area of occupancy (<10 km²) are both met. CR B1+2
• Main threats are water extraction and pollution, which affect the whole lake and the whole population: only one location. CR B1a+2a
• Habitat quality declining (water extraction causing increased salinity), declining population (now rare, ongoing habitat degradation).
CR B1b(iii,v)+2b(iii,v)
Can criterion B be applied?(Restricted geographic range AND severe fragmentation, continuing decline
and/or extreme fluctuations)
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
• Although the population is described as rare, it is difficult to estimate actual numbers of mature individuals from this.
NO
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
Can criterion C be applied?(Small population size and continuing decline)
IUCN (International Union for Conservation of Nature)
• Population size cannot be estimated from the information given.
• Species is restricted to only one, small location (AOO <10 km², 1 location).
• Continued transformation and pollution of the lake is likely to result in the disappearance of this species. VU D2
YES - VU D2
Can criterion D be applied?(Very small or restricted population)
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
• No quantitative analysis has been carried out.
NO
Can criterion E be applied?(Quantitative analysis estimating probability of extinction in the wild)
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
• Criterion A:
• Criterion B:
• Criterion C:
• Criterion D:
• Criterion E:
Final assessment:Taylor’s Salamander (Ambystoma taylori) is
Critically Endangered: CR B1ab(iii,v)+2ab(iii,v)
NO
CR B1ab(iii,v)+2ab(iii,v)
NO
VU D2
NO
Taylor’s Salamander, Taylor’s Salamander, Ambystoma tayloriAmbystoma taylori
IUCN (International Union for Conservation of Nature)
Case Study 2Case Study 2
Rhacophorus yinggelingensisRhacophorus yinggelingensis(Chou, Lau and Chan, 2007)(Chou, Lau and Chan, 2007)
IUCN (International Union for Conservation of Nature)
RangeCurrently known only from the Yinggeling Mountain range on Hainan Island, Hainan Province, southern China, at 1,300-1,550m asl (Chou et al., 2007). There are records from Mahuolong and Yinggezui (Chou et al., 2007). Its not been found in surveys of other mountains in Hainan despite surveys there, but it will probably be found in more sites in the Yinggeling Mountain Range (M.W.N. Lau pers. comm.). There are not many areas in Hainan above 1,300m asl (B. Chan pers. comm.).
PopulationIt appears to be a rare species, as during a three-month survey, only three specimens were found (B. Chan pers. comm.). The area of suitable habitat is very small (M.W.N. Lau pers. comm.).
Rhacophorus yinggelingensis
IUCN (International Union for Conservation of Nature)
Habitat & EcologyKnown only from primary montane rainforest (Chou et al., 2007). It has been found on the leaves of shrubs 30cm over a dried pool in a stream, and in sedges in a dried rain pool on a mountain ridge (Chou et al., 2007). It appears to be a montane species that breeds in still water, and there are not many suitable breeding habitats within its elevational range (M.W.N. Lau pers. comm.). It is not known if it can survive in opened up habitat.
Rhacophorus yinggelingensis
ThreatsThe montane habitat of the species is above the elevation at which human disturbance of the forest is taking place (Chou et al., 2007). The forest was given formal protection in 2004. The species could be at risk if climate change leads to a decrease in rainfall, as the species is believed to be dependent on rainpools for breeding, which are few and far between in the steep terrain where it lives.
Conservation MeasuresOccurs in the Yinggeling Nature Reserve (established in 2004). Surveys are needed to clarify the distribution, ecological requirements and conservation needs of this species.
IUCN (International Union for Conservation of Nature)
Criterion A
Criterion B
Criterion C
• Appears to be a rare species
• Not many suitable breeding habitats within its elevational range
• No specific information indicates a population decline
• No generation length given
• EOO and AOO not specified, but “area of suitable habitat is very small”
• Main threat = climate change leading to decreased rainfall: 1 location
• No continuing declines or extreme fluctuations
• Appears to be a rare species
• No specific population size estimates given
• No indication of a continuing decline
Maybe NT B1a+2a
Rhacophorus yinggelingensis
B1+B2?B1a+B2a?
IUCN (International Union for Conservation of Nature)VU D2
Criterion A
Criterion B Maybe NT B1a+2aCriterion C
Criterion D
Criterion E
• No specific population size estimates given
• 1 location; decrease in rainfall is a plausible future threat
• No quantitative analysis
VU D2
VU D2
Rhacophorus yinggelingensis
IUCN (International Union for Conservation of Nature)
Case Study 3Case Study 3
Sarus Crane, Sarus Crane, GGrus antigonerus antigoneViet Nam National Assessment (2003)Viet Nam National Assessment (2003)
IUCN (International Union for Conservation of Nature)
RangeA migrant species that spends the winter months in Viet Nam. Found in 3 disjunct global populations: the Indian subcontinent, Australia & South-east Asia (Cambodia, Viet Nam, Lao PDR, Myanmar; extinct in Thailand & probably China). Occurs in 2 locations in Viet Nam: Tram Chin, where it remains for 3 months/year, and Logo Samat, a stopover point for individuals heading to Cambodia, where it occurs irregularly and stays for 1 week. EOO = 700-900 km². AOO = 400 km².
Grus antigoneSarus Crane
Viet Nam National Assessment (2003)
Population>90% population decline in Tram Chin since 1990 (1990: 128 individuals; 2003: 2 individuals). General population decline in Logo Samat (1992: 7 individuals; 1998: 48 individuals, 2003: 0 individuals). Global population is also in decline.
IUCN (International Union for Conservation of Nature)
Habitat & EcologySoutheast Asian populations frequent open and man-made wetlands during the non-breeding season.
Sarus Crane, Grus antigone
ThreatsMain threats are habitat loss and degradation in Tram Chin due to the construction of an irrigation channel, pollution, and fire; habitat loss and degradation in Logo Samat due to encroachment from farmland, human disturbance, and hunting. Populations in neighbouring Thailand and Cambodia are uncertain, but probably stable.
Conservation MeasuresCITES Appendix II. Found in Tram Chin National Park.
IUCN (International Union for Conservation of Nature)
Criterion A
Criterion B
Criterion C
• Most individuals found in Tram Chin; irregular in Logo Samat
• Past population reduction of >90% in Tram Chin; general decline in Logo Samat (based on direct observations). No mention of projected future declines.
• Habitat loss & degradation in both sites; also hunted in Logo Samat.
• EOO = 700-900 km² and AOO = 400 km²
• 2 locations
• Continuing decline: quality and extent of habitat, # mature individuals
• 2003: 2 individuals recorded (no precise estimates, but < 250)
• Past continuing decline; no mention of future declines
• Most individuals in Tram Chin
CR A2acd
EN B1ab(iii,v)+2ab(iii,v)
CR C2a(ii)
CR A2a CR A2acd
EN B1+B2 EN B1a+B2a
EN B1ab(iii,v)+B2ab(iii,v)
CR C CR C
CR C2a(ii)
Sarus Crane, Grus antigone
IUCN (International Union for Conservation of Nature)CR A2acd; C2a(ii)
Criterion A CR A2acd
Criterion B EN B1ab(iii,v)+2ab(iii,v)Criterion C CR C2a(ii)
Criterion D
Criterion E
• < 250 individuals
• 2 locations; several existing threats
• No quantitative analysis
EN D and VU D2EN D VU D2
Sarus Crane, Grus antigone
IUCN (International Union for Conservation of Nature)
Case Study 4Case Study 4
Bordon’s Brachypterous Bordon’s Brachypterous Butterfly Butterfly Redonda bordoniRedonda bordoni
IUCN (International Union for Conservation of Nature)
TaxonomyButterflies of the genus Redonda are endemic to the Andes of Venezuela. This species was not described until 2003.
RangeEndemic to Venezuela and known only from 2 páramos in the Venezuelan Andes, from 3000-3800m. These 2 páramos and the areas between them make up El Batallón and La Negra National Park, which has an area of 952 km². The total area inhabited by the species (based on the combined area of the 2 páramos at the altitudinal range in which the species occurs) is around 180km².
Bordon’s Brachypterous Butterfly, Redonda
bordoni
IUCN (International Union for Conservation of Nature)
PopulationNo information. Anecdotal observations indicate that the species is relatively abundant in the region, especially males; the number of females is difficult to estimate as they remain hidden in low-lying vegetation.
Habitat & EcologyHas been found in open páramo and humid páramo in intermontane valleys. Males are active and easily found, but the wings of females are considerably reduced and deformed, so they are highly sedentary and make no attempts to fly. Females also have cryptic wings, and are only visible when showing the silvery uppersides. Females scatter their eggs while crawling.
Bordon’s Brachypterous Butterfly, Redonda bordoni
IUCN (International Union for Conservation of Nature)
ThreatsBelieved to be very fragile and particularly susceptible to environmental threats. Current threats include habitat loss and degradation due to the loss of host plants, trampling by grazing livestock, agriculture, and fire hazards during the dry season. All of these threaten the larvae, and the females are also particularly vulnerable as they are not very mobile.
Conservation MeasuresPresent within a national park, though whether the habitat within the park is adequately protected is questionable.
Bordon’s Brachypterous Butterfly, Redonda bordoni
IUCN (International Union for Conservation of Nature)
Criterion A
Criterion B
Criterion C
• No known population estimates or trends.
• Effects of threats on habitat not quantified, and R. bordoni’s precise response to those threats unknown = cannot indirectly measure population decline (inference, suspicion, projection).
• Total potential range = 952 km²
• Known inhabited area = 180 km²
• 2 locations
• Continuing decline inferred in quality of habitat.
• No extreme fluctuations.
EN B1ab(iii)+2ab(iii)
• No known population estimates or trends.
EN B1
EN B1a+2a
EN B1ab(iii)+2ab(iii)
EN B2
Bordon’s Brachypterous Butterfly, Redonda bordoni
IUCN (International Union for Conservation of Nature)EN B1ab(iii)+2ab(iii)
Criterion A
Criterion B EN B1ab(iii)+2ab(iii)
Criterion CCriterion D
Criterion E
• 2 locations
• Plausible threats: habitat loss & degradation, trampling, agriculture, fire.
• No quantitative analysis
VU D2
Bordon’s Brachypterous Butterfly, Redonda bordoni