Extinction: African elephants driven to the brink by poaching

The ivory trade, loss of vital habitat and a deeper understanding of elephant biology have all combined to reveal a previously underestimated threat to Africa's elephants.

African forest elephants are now critically endangered, BBC News reports, citing the International Union for the Conservation of Nature (IUCN).

Savanna elephants are also endangered.

And "declines over decades" have driven the species into the two highest categories of extinction threat.

African elephants were previously assessed as one species on the IUCN's Red List.

Genetic evidence showed them to be two distinct species more than a decade ago.

But accurate assessments - of populations, trends in their numbers and the threats they face - take many years.

The IUCN estimates 415,000 elephants remain in Africa.

But the number of forest elephants fell by more than 86% during the past three decades. In addition, the number of savanna elephants fell by at least 60% over the past 50 years.