The primary cause of species endangerment is

Step 1: Analyze the question The question asks for the primary (main, leading) cause of species becoming endangered. We need to pick the factor that affects the most species most seriously.

Step 2: Explain the concept A species is endangered when its population falls so low that it risks extinction. Conservation biologists identify several threats, often summarised as HIPPO:

• Habitat destruction and loss (the biggest)
• Invasive species
• Pollution
• Population growth of humans
• Overharvesting (hunting, overfishing)

Habitat loss comes from deforestation, farming, urbanisation, mining, and dam building. In Nigeria, for example, logging and farming have shrunk forest areas, threatening animals like the drill monkey, chimpanzee, and Cross River gorilla.

Step 3: Evaluate the options

• A. Disappearing habitats: Correct. When animals lose their homes, they lose food, shelter, and breeding sites. This affects the largest number of species.
• B. Increase in temperatures: Climate change is a growing threat, but it is not currently the leading cause.
• C. Acid rain: It harms some forests and water bodies, but its effect is localized and less widespread.
• D. Exposure to hazardous wastes: This is a form of pollution, which is harmful but secondary to habitat loss.

Step 4: Answer The primary cause of species endangerment is disappearing habitats (A).

Step 5: Exam tip When you see "primary" or "main cause" of endangerment or extinction, think habitat loss first. Remember HIPPO, with habitat at the top of the list.