IUCN CRITERIA FOR ENDANGERED SPECIES
CRITERIA IS AS FOLLOWS
EXTINCT (EX): A taxon is Extinct when there is no reasonable doubt that the last individual has died. A taxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.
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. A taxon is presumed Extinct in the Wild when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.
CRITICALLY ENDANGERED (CR) A taxon is Critically Endangered when the best available evidence indicates that it meets any of the criteria A to E for Critically Endangered (see Section V), and it is therefore considered to be facing an extremely high risk of extinction in the wild.
ENDANGERED (EN) A taxon is Endangered when the best available evidence indicates that it meets any of the criteria A to E for Endangered (see Section V), and it is therefore considered to be facing a very high risk of extinction in the wild.
VULNERABLE (VU) A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable (see Section V), and it is therefore considered to be facing a high risk of extinction in the wild.
NEAR THREATENED (NT) A taxon is Near Threatened when it has been evaluated against the criteria but does not qualify for Critically Endangered, Endangered or Vulnerable now, but is close to qualifying for or is likely to qualify for a threatened category in the near future.
LEAST CONCERN (LC) A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.
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. A taxon in this category may be well studied, and its biology well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore not a category of threat. Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future research will show that threatened classification is appropriate. It is important to make positive use of whatever data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified.
NOT EVALUATED (NE) A taxon is Not Evaluated when it has not yet been evaluated against the criteria.
Taita tree hyrax (Dendrohyrax sp.) and Taita dwarf galago (Paragalago cocos) fulfill following criteria for Critically Endangered species.
MORE DETAILED KNOWLEDGE ABOUT CRITICALLY ENDANGERED (CR)
IUCN guide about Critically Endangered:
A. Reduction in population size based on any of the following (shortened by Hanna Rosti), original with much longer text can be found here: IUCN Red List categories and criteria, version 3.1, second edition
A. Population size
- An observed, estimated, inferred or suspected population size reduction of ≥90% over the last 10 years based on direct observation, decline in area of occupancy, extent of occurrence and/or quality of habitat
- An observed, estimated, inferred or suspected population size reduction of ≥80% over the last 10 years where the reduction or its causes may not have ceased or may not be understood or may not be reversible.
B. Geographic range
- Extent of occurrence estimated to be less than 100 km2
- Area of occupancy estimated to be less than 10 km2
C. Population size estimated to number fewer than 250 mature individuals or
- A continuing decline, observed, projected, or inferred, in numbers of mature individuals. 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).
How IUCN assessment and criteria is made?
UCN criteria are made based on peer reviewed scientific journals, and they are written by top scientist of the species. Before IUCN assessment can be done, species must be scientifically identified and named.
Assessment is based on research. Collecting substantial knowledge, preferably long-term knowledge of each species in the planet is not always possible. Species are very different, and methods that different species are studied vary accordingly. There is lack of data on most nocturnal animals, simply because they are so difficult to study.
Publishing scientific articles is time consuming and expensive. It means that species may go extinct, or their IUCN status may change faster than can be noticed, as humans are changing Earth in ever-growing speed.
Taita tree hyrax and Taita dwarf galago are already CR Critically endangered
However, Taita tree hyrax and Taita dwarf galago don’t yet have any IUCN criteria. In Taita Hills there is about 6 km2 of indigenous tropical cloud forest left. This means that these species are Critially Endangered based on B2, area of occupancy less than 10 km2.
Forests that are left in Taita Hills are severely fragmented, and not connected to each other. So they are like islands in the sea. Forests are remaining in the mountain tops of Taita Hills, and they are also called water towers, as local people understand the ability of indigenous forest of attract rainwater.
Largest forest fragments are Mbololo 1,8 km2, and Ngangao 1,2 km2 and Chawia 0,8 km2. These are very small forests – all of them. Only Mbololo and Ngangao still have dwarf galago populations. Tree hyrax is more common, and it also survives in smaller fragments.
These severy fragmented forests are still source of firewood for some local people. A price of electricity is very high in Kenya, and using gas is also too expensive to some people. Firewood is used for cooking. Collection of firewood decreases quality of the forest, and signs are clearly visible on the edges and around paths inside the forest.
Populations are what matter!
All populations are worth conservation. Before species go extinct, population number may even increase in some area, if habitats are destroyed and animals are packed in remaining habitat. This is called extinction debt. Competition in remaining habitat will decrease number of animals.
If we wait with conservation efforts until 90 % of population is lost, it is too late!
Forms of life are connected to each other. What happens to one species, happens to many species. This is because species use other species as food sources and rely on other species as their habitat, reproduction, safety and habitat.
The web of life can decrease in countless ways that humans are unable to monitor, even with most high quality research.
In a another words, we can’t predict consequences to other species caused by one species of animal going Critically Endangered or Extinct.
All populations should be conserved in a level, where they have genetic biodiversity, resilience to changes and disease, capability to reproduce normally.
IUCN guidelines are necessary tool to evaluate and compare situations where species are.
However, more awareness should be given to each population, and conservation before species is Critically Endangered.
We are living sixth mass extinction, our responsibility is to protect other species, and keep populations of other species alive, resilient and strong.
Read also: Conservation of Mbololo and Ngangao Forests
Read also: Taita tree hyrax – mysterious relict species