News on this issue
In the year 2000, over 5400 animal species were listed by IUCN (World Conservation Union) as being in great danger of extinction in the near future. It is risky to view this number as a maximum figure as many species of animals still remain to be discovered and researched, though the numbers of birds and mammals are fairly reliable. Of Europeĺs 514 bird species, 195 have unfavourable conservation statues. Nearly 6000 plant species can also be found on the list ľ and of course, the animal kingdom cannot survive without plants.
To be on the edge of extinction has various meanings according to species as some species, e.g. invertebrates, can reproduce quickly in favourable conditions and so reach equilibrium anew in a relatively short period. Many animals, though, reproduce very slowly, which means their reappearance is much more difficult. One example is the albatross, which takes seven years to achieve sexual maturity and lays only one egg at a time, often only every second year. Some other species need to be in a large group in order for mating behaviour to begin.
Photo of Cheetahs. Credit: U.S.Fish and Wildlife Service, Stolz, Gary M.