Introduction to the IUCN Red Listing Process

IUCN (International Union for Conservation of Nature)

The IUCN Red List assessment estimates

risk of extinction

What is the likelihood of a species becoming extinct 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 & Criteria

All materials are freely available on IUCN Red List web site: www.iucnredlist.org

IUCN (International Union for Conservation of Nature)

Scope of Application

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 Categories and Criteria can be applied to

:

• • All described taxa (species, subspecies, varieties), except micro-organisms Taxa not yet formally described,

but only if

• A clearly distinct species; they are: • Museum/herbarium voucher references are provided; • Distribution information is available; • There is clear conservation benefit to assessing the species.

IUCN (International Union for Conservation of Nature)

Rabb’s Fringe-limbed Treefrog

Ecnomiohyla rabborum

Category: Critically Endangered

CR A2ace;B1ab(iii)

Criteria & subcriteria

IUCN (International Union for Conservation of Nature)

The IUCN Categories

Extinct (EX) Extinct in the Wild (EW) Critically Endangered (CR) Endangered (EN) Vulnerable (VU) Near Threatened (NT) Least Concern (LC) Data Deficient (DD) Not Evaluated (NE)

IUCN (International Union for Conservation of Nature)

Extinct (EX) A taxon is Extinct when there is no reasonable doubt that the last individual has died.

Dodo,

Raphus cucullatus

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

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 Endangered (EN) EN taxa are considered to be facing a very high risk of extinction in the wild

Photo © Wendy Strahm

Mandrinette,

Hibiscus fragilis

Black-browed Albatross,

Thalassarche melanophrys Photo © Tony Palliser

Vulnerable (VU) VU taxa are considered to be facing a high risk of

Golden Pagoda,

extinction in the wild

chrysanthus

Photo © Craig Hilton Taylor

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 .

Photo © H. Fraga

Macaronesian Laurel,

Laurus azorica

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.

IUCN (International Union for Conservation of Nature) Olive Baboon,

Papio anumbis

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 Tomato

Solanum [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)

Data Deficient (DD) Not Evaluated (NE)

Although DD and NE are not threatened categories, taxa classed as DD or NE should NOT be treated as not threatened

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 quality Observed Estimated Projected Inferred Suspected

IUCN (International Union for Conservation of Nature)

Observed

Observed information is directly based on well-documented observations of all known individuals in the population.

Estimated

Estimated information is based on calculations that may involve assumptions and/or interpolations in time (in the past).

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 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).

Suspected

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)

Dealing with data uncertainty

Uncertainty in the data itself (different to the lack of data) has to be considered in a Red List assessment 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 Size Subpopulations Mature Individuals Generation Length Reduction Continuing Decline

IUCN (International Union for Conservation of Nature)

Key terms used in the IUCN Red List criteria

Extreme Fluctuations Severely Fragmented Extent of Occurrence Area of Occupancy Location Quantitative Analysis

IUCN (International Union for Conservation of Nature)

Population and Population Size Population

is the total number of individuals of a given taxon across its global range.

Population size

is measured as the number of mature individuals only.

Subpopulations Subpopulations

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 Individuals Mature Individuals

are individuals that are known, estimated or inferred to be capable of reproduction.

IUCN (International Union for Conservation of Nature)

Population Subpopulations Population Size (mature individuals only)

IUCN (International Union for Conservation of Nature)

Generation 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)

Reduction Reduction

is a decline in population size of at least the % stated in criterion A over the specified time period.

Population Size Time Continuing Decline Continuing Decline

is a recent, current or projected future decline which is liable to continue unless

Extreme 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)

Extreme Fluctuations

25,000 20,000 15,000 10,000 5,000 0 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

IUCN (International Union for Conservation of Nature)

Extreme Fluctuations

25,000 20,000 15,000 10,000 5,000 0 Jan '02 July '02 Jan '03 July '03 Jan '04 July '04 Jan '05 July '05 Jan '06 July '06 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

Severely 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)

Severely Fragmented 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.

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 Area of Occupancy 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 ).

IUCN (International Union for Conservation of Nature)

Extent 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:

Threatening event AOO = 10x4 = 40 km 2 EOO = 44 km² AOO = 10x4 = 40 km 2 EOO = 105 km²

Extent 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: One major threatening event caused:

30% decline in AOO, 36% decline in EOO, >39% decline in population size

One major threatening event caused:

20% decline in AOO, 22% decline in EOO, <20% decline in population size AOO = 7x4 = 28 km 2 EOO = 28 km² AOO = 8x4 = 32 km EOO = 82 km² 2

Area of Occupancy Problems of Scale Grid Cells 16 units² Grid Cell = 1 unit² AOO = 3 x 16 = 48 units 2 AOO = 10 x 1 = 10 units 2 In many cases, a grid size of 2 km (i.e., cell area 4 km² ) is an appropriate scale.

Location

Location

is a geographically or ecologically distinct area in which

a single threatening event can rapidly affect all individuals of the taxon.

IUCN (International Union for Conservation of Nature)

Location Invasive species 2 locations

IUCN (International Union for Conservation of Nature)

Location Pollution 4 locations

IUCN (International Union for Conservation of Nature)

Location Pollution 4-5 locations

IUCN (International Union for Conservation of Nature)

Quantitative 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)).

= oh ohh!

IUCN (International Union for Conservation of Nature)

The IUCN Red List Criteria

IUCN (International Union for Conservation of Nature)

Nature of the Criteria

A

CRITERIA

Population reduction

THREATENED CATEGORIES

B Restricted geographic range C D E Small population size & decline Very small or restricted population Quantitative analysis Quantitative thresholds Critically Endangered (CR) Endangered (EN) Vulnerable (VU)

IUCN (International Union for Conservation of Nature)

Why use multiple criteria?

Not all the criteria are appropriate to all taxa.

• • •

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.

IUCN (International Union for Conservation of Nature)

IUCN (International Union for Conservation of Nature)

Criterion A Past, present or future population reduction

Population Size Time

IUCN (International Union for Conservation of Nature)

Criterion A Based on any of four criteria: A1:

Population reduction in

decline now ceased past

and

causes of A2:

Population reduction in

decline ongoing past

and

causes of A3:

Population reduction expected in

future A4:

Population reduction in

past AND future

IUCN (International Union for Conservation of Nature)

Criterion A1

past reduction & causes understood & ceased & reduction is reversible 

50% Vulnerable



70% Endangered



90% Critically Endangered Present Last 10 years or 3 generations (whichever is longer) Criterion A2

past reduction & causes may not be understood or may not have ceased or reduction may not be reversible 

30% Vulnerable



50% Endangered



80% Critically Endangered Last 10 years or 3 generations (whichever is longer)

Sub-criterion A3

future decline  30%

Vulnerable

 50%

Endangered

 80%

Critically Endangered Present Next 10 years or 3 generations (whichever is longer up to a maximum of 100 years) Sub-criterion A4

past & future  30%

Vulnerable

 50%

Endangered

 80%

Critically Endangered Present 10 years or 3 generations

IUCN (International Union for Conservation of Nature)

(whichever is longer, up to a maximim of 100 years in the future) including some time in the past AND in the future

Sub-criterion A4

past & future: “shifting time window”

5 years / 1.5 generations Present 5 years / 1.5 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

Use any of the criteria A-E

Critically Endangered Endangered Vulnerable A. Population reduction

Declines measured over the longer of 10 years or 3 generations

A1 A2, A3 & A4

 90%  80%  70%  50%   50% 30%

A1

. 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)

direct observation

(b)

an index of abundance appropriate to the taxon

(c)

a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality

(d)

actual or potential levels of exploitation

(e)

Effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites

A2

. 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.

A3

. 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.

A4

. 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.

Criterion A

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 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)

.

IUCN (International Union for Conservation of Nature)

Criterion B Restricted geographic range and fragmentation, continuing decline or extreme fluctuations

IUCN (International Union for Conservation of Nature)

Criterion B Based on either of two sub-criteria:

B1:

Estimated extent of occurrence

AND / OR B2:

Estimated area of occupancy

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

CR EN Subcriterion B1

Extent of occurrence estimated to be: < 100 km²

Subcriterion B2

Area of occupancy estimated to be: < 10 km² < 5,000 km² < 500 km²

VU

< 20,000 km² < 2,000 km² IUCN (International Union for Conservation of Nature)

Criterion B

AND

at least

TWO

of a, b or c:

CR EN VU a. Severely fragmented or # locations:

1  5  10

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-E

Critically Endangered Endangered Vulnerable B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy) B1 B2

. Extent of occurrence . Area of occupancy < 100 km² < 10 km² < 5,000 km² < 500 km² < 20,000 km² < 2,000 km²

AND at least 2 of the following (a)

Severely fragmented,

OR

Number of locations = 1 ≤ 5 ≤ 10

(b)

Continuing decline in any of:

(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:

(i)

extent of occurrence;

(ii)

area of occupancy;

(iii)

number of locations or subpopulations;

(iv)

number of mature individuals IUCN (International Union for Conservation of Nature)

Criterion B

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.

IUCN (International Union for Conservation of Nature)

Criterion C Small population size and continuing decline

IUCN (International Union for Conservation of Nature)

Criterion C Based on small population size AND either

C1

or

C2

:

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)

CR EN VU

Criterion C

Thresholds for criterion C

Population size is estimated at: < 250 mature individuals < 2,500 mature individuals < 10,000 mature individuals IUCN (International Union for Conservation of Nature)

Criterion C

CR EN VU Subcriterion C1

Estimated continuing decline of:  25% within 3 years or 1 generation  20% within 5 years or 2 generations  10% within 10 years or 3 generations IUCN (International Union for Conservation of Nature)

Criterion C

Subcriterion C2

Observed, projected or inferred continuing decline

at any rate AND at least one

of the following:

CR C2a(i)

.

All subpopulations have: < 50 mature individuals

C2a(ii)

.

One subpopulation contains:  90% of the mature individuals

EN

< 250 mature individuals  95% of the mature individuals

VU

< 1,000 mature individuals 100% of the mature

C2b

.

There are extreme fluctuations in number of mature individuals.

Use any of the criteria A-E

Critically Endangered Endangered Vulnerable C. Small population size and decline

Number of mature individuals < 250

AND either C1 or C2

:

C1.

An estimated continuing decline of at least: 25% in 3 years or 1 generation (up to a maximum of 100 years in future)

C2.

A continuing decline

AND

(a) and/or (b):

(a i)

number of mature individuals in each subpopulation:

(a ii)

or % individuals in one subpopulation = < 50 90-100%

(b)

extreme fluctuations in the number of mature individuals < 2,500 20% in 5 years or 2 generations < 250 95-100% < 10,000 10% in 10 years or 3 generations < 1,000 100% IUCN (International Union for Conservation of Nature)

Criterion C

Points to remember:

• The population size threshold must be met

before

thresholds for subcriteria C1 or C2.

considering the • 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

.

IUCN (International Union for Conservation of Nature)

Criterion D Very small or restricted population

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.

CR D

. Total current population size estimated as: < 50 mature individuals

NOTE

:

for the VU D2, there should be a plausible threat that is likely to rapidly affect the population.

EN

< 250 mature individuals

VU D1

. Total current population size estimated as: < 1,000 mature individuals

D2

. The population has a very restricted AOO

km²) (typically <20

or is known from very few locations

(typically ≤5)

.

Use any of the criteria A-E

Critically Endangered D. Very small or restricted population Either:

Number of mature individuals < 50

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.

Endangered

< 250

Vulnerable D1.

< 1,000

AND / OR D2.

typically: AOO < 20 km² or number of locations ≤ 5 IUCN (International Union for Conservation of Nature)

Criterion D

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.

IUCN (International Union for Conservation of Nature)

Criterion E Quantitative analysis

= oh ohh!

IUCN (International Union for Conservation of Nature)

Criterion E Based on quantitative analysis showing a probability of extinction in the wild is at least :

50% 20% Critically Endangered Endangered 10% Vulnerable

Within

10 years

or

3 generations

Within

20 years

or

5 generations

Within

100 years

Up to a

maximum

of

100 years

in the future IUCN (International Union for Conservation of Nature)

Use any of the criteria A-E

Critically Endangered Endangered Vulnerable E. Quantitative analysis

Indicating the probability of 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)

RED LIST DOCUMENTATION

• 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).

• • • • • • 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

Case Study 1

Taylor’s Salamander

Ambystoma taylori

Taylor’s Salamander,

Ambystoma taylori

Taxonomy

Based 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.

Range

Taylor’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)

Taylor’s Salamander,

Ambystoma taylori

Population

Even 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 & Ecology

This 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.

IUCN (International Union for Conservation of Nature)

Taylor’s Salamander,

Ambystoma taylori

Threats

The 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 Measures

Taylor’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)

Taylor’s Salamander,

Ambystoma taylori

Is the taxon eligible for Red List assessment?

• Description of the species has been published (Brandon, Maruska & Rumph, 1981).

YES

IUCN (International Union for Conservation of Nature)

Taylor’s Salamander,

Ambystoma 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) • 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

IUCN (International Union for Conservation of Nature)

Taylor’s Salamander,

Ambystoma taylori

Can criterion B be applied?

(Restricted geographic range AND severe fragmentation, continuing decline and/or extreme fluctuations) • 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)

YES – CR B1ab(iii,v)+2ab(iii,v)

Taylor’s Salamander,

Ambystoma taylori

Can criterion C be applied?

(Small population size and continuing decline) • Although the population is described as rare, it is difficult to estimate actual numbers of mature individuals from this.

NO

IUCN (International Union for Conservation of Nature)

Taylor’s Salamander,

Ambystoma taylori

Can criterion D be applied?

(Very small or restricted population) • 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

Taylor’s Salamander,

Ambystoma taylori

Can criterion E be applied?

(Quantitative analysis estimating probability of extinction in the wild) • No quantitative analysis has been carried out.

NO

IUCN (International Union for Conservation of Nature)

Taylor’s Salamander,

Ambystoma taylori

• Criterion A: NO • Criterion B: CR B1ab(iii,v)+2ab(iii,v) • Criterion C: NO • Criterion D: VU D2 • Criterion E: NO

Final assessment:

Taylor’s Salamander (Ambystoma taylori) is

IUCN (International Union for Conservation of Nature)

Critically Endangered: CR B1ab(iii,v)+2ab(iii,v)

Case Study 2

Rhacophorus yinggelingensis

(Chou, Lau and Chan, 2007)

IUCN (International Union for Conservation of Nature)

Rhacophorus yinggelingensis

Range

Currently 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.).

Population

It appears to be a rare species, as during a three-month survey, only three specimens were found (B. Chan pers. comm.). The area of

Rhacophorus yinggelingensis

Habitat & Ecology

Known 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.

Threats

The 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 Measures

Occurs in the Yinggeling Nature Reserve (established in 2004). Surveys are needed species.

Rhacophorus yinggelingensis

Criterion A

• 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

Criterion B Maybe NT B1a+2a

• EOO and AOO not specified, but “area of suitable habitat is very small” B1+B2?

• Main threat = climate change leading to decreased rainfall: 1 location B1a+B2a?

• No continuing declines or extreme fluctuations

Criterion C

• Appears to be a rare species • No specific population size estimates given • No indication of a continuing decline IUCN (International Union for Conservation of Nature)

Rhacophorus yinggelingensis

Criterion A Criterion B Maybe NT B1a+2a Criterion C Criterion D VU D2

• No specific population size estimates given • 1 location; decrease in rainfall is a plausible future threat

Criterion E

• No quantitative analysis VU D2

VU D2

IUCN (International Union for Conservation of Nature)

Case Study 3

Sarus Crane,

Grus antigone

Sarus Crane

Grus antigone

Viet Nam National Assessment (2003) Range

A 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.

Population

>90% population decline in Tram Chin since 1990 (1990: 128 individuals; 2003: 2 individuals). General population decline in Logo Samat (1992: 7 is also in decline.

Sarus Crane, Grus antigone Habitat & Ecology

Southeast Asian populations frequent open and man-made wetlands during the non-breeding season.

Threats

Main 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 Measures

Sarus Crane, Grus antigone Criterion A CR A2acd

• 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.

CR A2a • Habitat loss & degradation in both sites; also hunted in Logo Samat.

CR A2acd

Criterion B EN B1ab(iii,v)+2ab(iii,v)

• EOO = 700-900 km² and AOO = 400 km² EN B1+B2 • 2 locations EN B1a+B2a • Continuing decline: quality and extent of habitat, # mature individuals EN B1ab(iii,v)+B2ab(iii,v)

Criterion C CR C2a(ii)

• 2003: 2 individuals recorded (no precise estimates, but < 250) • Past continuing decline; no mention of future declines • Most individuals in Tram Chin CR C CR C

Sarus Crane, Grus antigone Criterion A CR A2acd Criterion B EN B1ab(iii,v)+2ab(iii,v) Criterion C CR C2a(ii) Criterion D EN D

and

VU D2

• < 250 individuals • 2 locations; several existing threats

Criterion E

• No quantitative analysis EN D VU D2 IUCN (International Union for Conservation of Nature)

CR A2acd; C2a(ii)

Case Study 4

Bordon’s Brachypterous Butterfly

Bordon’s Brachypterous Butterfly, Redonda bordoni

Taxonomy

Butterflies of the genus

Redonda

are endemic to the Andes of Venezuela. This species was not described until 2003.

Range

Endemic 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 Population

No 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 & Ecology

Has 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.

IUCN (International Union for Conservation of Nature)

Bordon’s Brachypterous Butterfly, Redonda bordoni Threats

Believed 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 Measures

Present within a national park, though whether the habitat within the park is adequately protected is questionable.

IUCN (International Union for Conservation of Nature)

Bordon’s Brachypterous Butterfly, Redonda bordoni Criterion A

• 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).

Criterion B EN B1ab(iii)+2ab(iii)

• Total potential range = 952 km² • Known inhabited area = 180 km² • 2 locations • Continuing decline inferred in quality of habitat.

• No extreme fluctuations.

Criterion C

• No known population estimates or trends.

EN B1 EN B2 EN B1a+2a EN B1ab(iii)+2ab(iii) IUCN (International Union for Conservation of Nature)

Bordon’s Brachypterous Butterfly, Redonda bordoni Criterion A Criterion B EN B1ab(iii)+2ab(iii) Criterion C Criterion D VU D2

• 2 locations • Plausible threats: habitat loss & degradation, trampling, agriculture, fire.

Criterion E

• No quantitative analysis IUCN (International Union for Conservation of Nature)

EN B1ab(iii)+2ab(iii)