Vulnerable species


A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as likely to become endangered unless the circumstances that are threatening its survival decrease and reproduction of that species improve.
Vulnerability is mainly caused by habitat loss or destruction of the species home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity, an example being the military macaw.
There are currently 5196 animals and 6789 plants classified as vulnerable, compared with 1998 levels of 2815 and 3222, respectively. Practices such as Cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically.

Criteria

The International Union for Conservation of Nature uses several criteria to enter species in this category. A taxon is Vulnerable when it is not critically endangered or Endangered but is facing a high risk of extinction in the wild in the medium-term future, as defined by any of the following criteria :
A) Population reduction in the form of either 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, provided the causes of the reduction are clearly reversible AND understood AND ceased. This measurement is based on any of the following:
  2. #direct observation
  3. #an index of abundance appropriate for the taxon
  4. #a decline in area of occupancy, extent of occurrence or quality of habitat
  5. #actual or potential levels of exploitation
  6. #the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites.
  7. A reduction of at least 20%, projected or suspected to be met within the next ten years or three generations, whichever is the longer, based on any of,, or above.
B) Extent of occurrence estimated to be less than 20,000 km2 or area of occupancy estimated to be less than 2000 km2, and estimates indicating any two of the following:

  1. Severely fragmented or known to exist at no more than ten locations.
  2. Continuing decline, inferred, observed or projected, in any of the following:
  3. #extent of occurrence
  4. #area of occupancy
  5. #area, extent or quality of habitat
  6. #number of locations or subpopulations
  7. #number of mature individuals
  8. Extreme fluctuations in any of the following:
  9. #extent of occurrence
  10. #area of occupancy
  11. #number of locations or subpopulations
  12. #number of mature individuals
C) Population 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, or
  2. A continuing decline, observed, projected, or inferred, in numbers of mature individuals and population structure in the form of either:
  3. #severely fragmented
  4. #all mature individuals are in a single subpopulation
D) Population very small or restricted in the form of either of the following:
  1. Population estimated to number less than 1000 mature individuals.
  2. Population is characterised by an acute restriction in its area of occupancy or in the number of locations. Such a taxon would thus be prone to the effects of human activities within a very short period of time in an unforeseeable future, and is thus capable of becoming Critically Endangered or even Extinct in a very short period.
E) Quantitative analysis showing the probability of extinction in the wild is at least 10% within 100 years.
The examples of vulnerable animal species are hyacinth macaw, mountain zebra, gaur, black crowned crane and blue crane