Which group is claimed to account for the largest extinction rate worldwide since 1500?

• A. Birds
• B. Reptiles
• C. Mammals
• D. Amphibians

Answer: (C)

Focusing on how human activity has driven recent losses helps explain why mammals show the largest extinction rate since 1500. Mammals have been heavily affected by habitat destruction, overhunting and trade, introduced predators and diseases, and rapid land‑use changes that shrink and fragment their ranges. Many mammal species are small or isolated on islands or in restricted habitats, so when habitats disappear or pressures intensify, their populations collapse quickly. That combination of vulnerability and widespread human impact has led to more documented extinctions in this group than in the others listed.

While amphibians, birds, and reptiles face serious declines and a high proportion of threatened species, the number of actual extinctions recorded since 1500 is not as high for those groups as it is for mammals, which is why mammals is the best-supported choice.