While some African elephants roam the savannah and delight tourists on safari, others are more discreet. They hide in the woods and eat fruit.

“You feel pretty happy when you see them,” said Kathleen Gobush, a Seattle-based conservation biologist and member of the African Elephant Specialist Group within the International Union for Conservation of Nature (IUCN)

The threat of extinction has decreased the chances of spotting one of these wood-dwelling elephants in recent decades. This comes from a new assessment of the IUCN Red List for African elephants, published on Thursday. The Red List categorizes species according to their risk of disappearing from the world forever. The new assessment is the first in which the Conservation Union treats Africa’s forest and savanna elephants as two species rather than one.

Both are in bad shape. The last time the group rated African elephants was in 2008 they were classified as endangered. Now it is said that savannah elephants are endangered, one category worse.

The shy forest elephants have lost almost nine tenths of their numbers in a generation and are now threatened with extinction – just one step away from extinction in the wild.

Under the direction of Dr. Gobush, the assessment team collected data from 495 locations across Africa. Using a statistical model, they were able to use the elephant numbers from each location to see broader trends for both species.

“We were essentially looking at data from as far back as possible,” said Dr. Gobush. The IUCN is aiming for three generations of data to get a complete picture of an animal’s wellbeing. But that’s a challenge for the long-lived elephants. The average mother of a savannah elephant gives birth to a child at 25 years of age. Forest elephant mothers are on average 31 years old. Since the earliest polls researchers could find were from the 1960s and 1970s, they could only look back two generations for savanna elephants and one generation for forest elephants.

Even in those few decades, the changes were drastic. According to the team, the savannah elephant population has dropped by at least 60 percent. Forest elephants have declined by more than 86 percent.

“This is alarming,” said Ben Okita, a Nairobi-based conservation biologist with Save the Elephants. Dr. Okita is co-chair of the Conservation Union’s African Elephant Specialist Group but has not worked on the new assessment.

Dr. Okita said that looking at the two species of elephant separately helps show how bad things are, especially for the forest elephant.

“The forest elephants were largely ignored for the most part,” he said. The grouping of the two elephants likely masked how bad things were for the forest elephant, he said.

The IUCN made the change because in recent years “it has become clear that these two species are genetically different,” said Dr. Okita. The final evidence for the Conservation Union was a 2019 study commissioned by it, which showed that the two elephants rarely reproduce with each other.

Alfred Roca, a geneticist at the University of Illinois at Urbana-Champaign, said the IUCN’s recognition of two African elephant species was a little late. More than two decades ago, a study of 295 skulls in museums found “enormous differences” between the two types of elephants, he said. In life, forest elephants have smaller bodies, rounder ears, and straight tusks than savannah elephants.

Genetically, “the separation between them is likely greater than the separation between lions and tigers,” said Dr. Roca.

Still, he said, “It’s never too late. I am very happy that you did this because it really highlights the dire situation that the forest elephant is in. “

According to Dr. Roca will find it particularly difficult for forest elephants to recover as they wait to reproduce – six years longer than the savannah elephants. The IUCN assessment also found that 70 percent of forest elephants could live outside of protected areas, making them particularly vulnerable to ivory poachers.

Elephants killed for their ivory tusks are not a new problem, and neither is habitat loss.

“It is the same two main threats that have haunted animals forever,” said Dr. Gobush. Poaching comes in waves, she added; it was particularly severe in the 1980s and peaked again in 2011.

Where elephants disappear, they leave a huge void – not only physically but also in their work. Some tree species rely solely on forest elephants to eat their fruits, swallow their large seeds and deposit them elsewhere in a dung heap.

As they cut trees and chew large amounts of plant material, both forest and savanna elephants change their environment in ways that create new habitats for other species.

“Both of them could really be viewed as gardeners taking care of the vegetation, more than likely any other animal,” said Dr. Gobush. “We just can’t really afford to lose her.”

But there is good news.

Savannah elephants “thrive,” said Dr. Okita, in the cross-border nature reserve Kavango Zambezi, which overlaps five countries in southern Africa. In some parts of Gabon and the Republic of the Congo, forest elephant populations have stabilized or even increased. Where people protect elephants from poachers and carefully plan land use, Dr. Okita made progress.

He wonders, however, whether reversing the decline of the African elephants not only requires politics, but also reaches people on a personal level and gives them the urgency to do so.

“Right now we’re getting to people’s heads,” said Dr. Okita. “But we have to get to the heart.”