Classification of Threatened series is, as mentioned below:
1. Endangered Species: In endangered species, either the number of these organisms is declined or their habitat is shrunk to such an extent that they will be extinct in the near future if conservative measures are not followed. Examples include Lion tailed monkey, lesser florican, etc.
2. Rare Species: These species are depleted, and the number of organisms has declined considerably. Organisms of these species being endemic may be extinct faster. Example: Red Panda. Musk deer and so on.
3. Vulnerable Species: There are very few of these organisms and it continues to decline. A continuous decline in their number is a thing of worry. Examples are Lion, Tiger and so on.
4. Indeterminate Species: These organisms are endangered because of some of their behavioural habits such as shyness. There is not much definite or substantial evidence about the organism. Giant Squirrel is an example.