Extinction is Forever


Whooping Crane
from Audubon magazine

          According to Thomas Y. Canby in his book Our Changing Earth, "When authorities rank threats to the environment, most head their list with global warming, ozone depletion, and the threat to biodiversity. The first two problems are reversible - global warming and ozone loss can be halted, even forced into retreat. Not so with biodiversity". Scientists have catalogued more than one and a half million species in existence today, but other researchers believe there are far more than that not yet discovered. With up to 100 species becoming extinct every day we may never know of them all. Harvard University biologist, E.O. Wilson estimates that at least 4,000 - 6,000 species become extinct each year just from the decimation of tropical rainforests. If present trends remain stable, 50% of all species will be endangered or extinct in the next few decades.

Fur Seal
from Audubon magazine
          The World Conservation Union (IUCN) is an organization dedicated to collecting the most extensive information on species that are at risk for extinction. The 2000 IUCN Red List reveals some alarming statistics. "Of the 18,276 organisms investigated, 11,046 - including 24% of mammals and 12% of birds - are threatened with extinction." (Andrea Dorfman Time Magazine) This is frightening when you realize that there are many more species on the planet that were not studied. The main causes for the endangerment of these organisms centers around habitat degradation, hunting (for food, medicine, or trade), pollution, and the introduction of other non-native species competing for the same resources.
The categories that the IUCN use can be confusing. Here they are, explained:

Bald Eagle
from Audubon magazine
EXTINCT (EX)
A taxon is Extinct when there is no reasonable doubt that the last individual has died.
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 naturalised population (or populations) well outside the past range.
CRITICALLY ENDANGERED (CR)
A taxon is Critically Endangered when it is facing an extremely high risk of extinction in the wild in the immediate future.
ENDANGERED (EN)
A taxon is Endangered when it is not Critically Endangered but is facing a very high risk of extinction in the wild in the near future.
VULNERABLE (VU)
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.
LOWER RISK (LR)
A taxon is Lower Risk when it has been evaluated, does not satisfy the criteria for any of the categories Critically Endangered, Endangered or Vulnerable. Taxa included in the Lower Risk category can be separated into three subcategories:
  1. Conservation Dependent - (cd) Taxa which are the focus of a continuing taxon-specific or habitat-specific conservation programme targeted towards the taxon in question, the cessation of which would result in the taxon qualifying for one of the threatened categories above within a period of five years.
  2. Near Threatened - (nt) Taxa which do not qualify for Conservation Dependent, but which are close to qualifying for Vulnerable.
  3. Least Concern - (lc) Taxa which do not qualify for conservation Dependent or near Threatened.
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.
NOT EVALUATED (NE)
A taxon is Not Evaluated when it has not yet been assessed against the criteria.

Elephant
from Wildlife Conservation magazine




Ask now the beasts, and they shall teach thee;
And the fowls of the air and they shall tell thee,
Or, speak to the earth, and it shall teach thee.
- Book of Job


For a list of things you can do to ease the pressure on threatened species, Click here

Resources:
Our Changing Earth - Thomas Canby
Andrea Dorfman - Time Magazine
Audubon: Natural Priorities - Roger DiSilvestro
IUCN - World Conservation Union

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