4. Vulnerability is mainly caused
by habitat loss or destruction.
A vulnerable species is one which
has been categorized by
the International Union for
Conservation of Nature as likely to
become endangered unless the
circumstances threatening its
survival.
8. A rare species is a group of organisms that are
very uncommon, scarce, or infrequently
encountered.
This designation may be applied to either a plant
or animal taxon.
Designation of a rare species may be made by an
official body, such as a national government,
state, or province.
9.
10.
11. An endangered species is one
which has been categorised by the
International Union for
Conservation of Nature as likely to
become extinct. Conservation
biologists use the IUCN Red List,
where "endangered" is the second
most severe conservation status
for wild populations, following
critically endangered.
12. 3079 animals and 2655 plants
are endangered worldwide,
compared with 1998 levels of
1102 and 1197, respectively.
The amount, population trend,
and conservation status of
each species can be found in
the lists of organisms by
population