Scientists from around the world are calling for increased efforts to protect many of the Earth’s largest and most enchanting species before humanity wipes them out.

In an open letter published Wednesday in the journal BioScience, 43 wildlife researchers warn of a bleak future where elephants, gorillas and nearly a hundred lesser-known species could disappear from the planet without urgent intervention.

“Under a business-as-usual scenario, conservation scientists will soon be busy writing obituaries for species and subspecies of megafauna as they vanish from the planet,” write the authors, from groups including the Wildlife Conservation Society, Zoological Society of London and Panthera.

Nearly two-thirds of the world’s largest herbivores and carnivores are classified as threatened with extinction by the International Union for the Conservation of Nature, which tracks such threats.

But few have garnered any significant attention, said William Ripple, a professor at Oregon State University and the lead author of the letter. Species like the African wild ass and the banteng are suffering alongside the enigmatic rhino and Siberian tiger.

“Extinction is forever,” he said. “For some species, it’s going to be too late if we don’t act soon. You can go down the list; especially among the herbivores, these animals are in obscure tropical locations where people all over don’t know about them.”

Credit: Varun R. Goswami An Indian wild water buffalo, listed as endangered. The total world population of wild water buffalo is almost certainly fewer than 4,000 animals and could be fewer than 200.

The letter, which Ripple referred to as both a manifesto and a call-to-arms, paints a stark picture about the ongoing trials wildlife face. Humans have hunted, poisoned, eaten and shot many species into near-extinction. Some, like the western black rhino and Vietnamese subspecies of the Javan rhino, have already vanished.

Ripple and the letter’s co-signers drafted a 13-point declaration. Part of it calls on rich nations to shoulder a large burden of future protection efforts were humanity to successfully avert future extinctions. Regions like sub-Saharan Africa and Southeast Asia, which hold the bulk of large wildlife, often lack the budget to conduct such efforts by themselves.

“The onus is on developed countries,” they write. “For conservation efforts to be successful, actions should be taken at all levels by authorities who have the public interest in mind.”

Credit: Halska Hrabar Threatened mountain zebras are at risk from threats including agriculture and hunting.

“I personally think that the governments in the rich countries should bear a lot of the cost,” Ripple said. “We are not even close to the amount of funding for the conservation of these animals and the research needed to describe their situation.”

The authors hope such a declaration, a relatively uncommon move in the scientific community, will help raise awareness about the ongoing plight of the planet’s wildlife. Ripple said such a serious issue “needs to be a priority” that spans beyond a lone moment of outrage over a dead lion or giraffe.

“Without such a transformation, there is a risk that many of the world’s most iconic species may not survive to the twenty-second century,” the letter reads. “We must not go quietly into this impoverished future.”