If we don’t act now, future generations, may only see giraffes in encyclopedias and museums.

The planet’s tallest animal is now facing a threat of potentially being wiped off the face of the earth with two subspecies listed as “critically endangered” for the first time.

According to the latest report of the International Union for Conservation of Nature (IUCN), the Rothschild’s giraffe is “near threatened.”

Dr. Julian Fennessy, co-chair of the IUCN Species Survival Commission Giraffe and Okapi Specialist Group (SSC GOSG) and director of the Giraffe Conservation Foundation (GCF), warned that the gentle giants are undergoing “silent extinction.”

“The world’s tallest animal is under severe pressure in some of its core ranges across East, Central and West Africa. It may come as a shock that three of the currently recognized nine subspecies are now considered ‘critically endangered’ or ‘endangered,’ but we have been sounding the alarm for a few years now,” he explained in a statement.

Like most reasons for endangerment, humans are the largest threat to the iconic animals. The habitat loss through expansion of agriculture and mining, increasing human-wildlife conflict, illegal hunting, and civil unrest are all factors that are contributing to the giraffe’s dwindling population.