Answer:
When there is a huge influence of factor (or more factors) that affect the survival of the species.
Step-by-step explanation:
List of Endangered and Threatened species is a list of living organisms that need protection.
- endangered means it the species is in danger of extinction
- threatened means that the species is in the stadium before becoming endangered
Factors that affect the survival of the species are:
- destruction or modification of their habitat (usually under the influence of human activity)
- disease
- high predation influence
- overutilization of an animal or plant (for comercial, educational or other purposes)
- natural disasters etc.