Imagine being one of just 100 humans left on the planet. While it seems like something out of a disaster movie (the CW's The 100 comes to mind), it's actually a reality for a number of exceedingly rare animals. These critically endangered species are under constant threat. While animals with very small populations like the red-crested tree rat have miraculously appeared after centuries of presumed extinction, other species aren't so lucky. The case of the White Rhino begs the question "how do you bring back a species with just one elderly male in existence?" and the Seychelles sheath-tailed bat is losing a difficult battle against nature.
These 12 animals are among the rarest in the world – less than 100 of them exist in the wild. Although conservation efforts are being made to save these species, will it be enough?
Red-Crested Tree Rat
Population: Unknown, but in 1898, just two red-crested tree rats existed in captivity. For over a century, the species had not been spotted in the wild.
What Happened: In May 2011, a red-crested tree rat was spotted for the first time in 113 years by two biologists who were camping in a field. From this single sighting, it's impossible to say how many of these rats exist, but there's probably a handful – at least around Colombia's El Dorado Nature Reserve where the first little guy was found.
Because of the sighting, the rat was able to nab a listing as "critically endangered" rather than "extinct."
What Happened: Rhinos as a whole are struggling with poaching and the destruction of their natural habitat. It's very possible that during your lifetime, rhinos will no longer exist in the wild. The white rhino is particularly vulnerable because there's just a single male, named Sudan, in existence. The other two white rhinos, named Fatu and Najin, are females. All of the remaining white rhinos live at the Ol Pejeta Conservancy in Kenya where they are guarded from poachers around the clock.
Unfortunately, Sudan is elderly and has a low sperm count. While Fatu is a young 15 years old, Najin is 25 and has weak hind legs which may not support natural mating.see more on White Rhinoceros
Red River Giant Softshell Turtles
Population: Three (two in captivity, one in the wild)
What Happened: The Red River giant softshell turtle is so endangered that only three of them exist in the entire world. Two are at the Suzhou Zoo in China, and one is in a lake in Vietnam called Dong Mo. Their dwindling population is largely the fault of China's industrialization and the push for renewable energy, which caused a number of dams to be built along the river. As China developed their infrastructure around the Red River in the mid-to-late 20th century, the turtles' habitat was decimated.
In addition to a shrinking habitat, pollution has made it almost impossible for the turtles to hunt. Even if they can thrive in musky, polluted water, Red River giant softshell turtles are particularly vulnerable to poachers: their eggs, meat, and skin are all used in Eastern medicine.
Population: Less than 25
What Happened: The Hainan gibbon, which resides on the Hainan islands in the South China Sea, is the world's rarest primate. Over the last 50 years, deforestation has destroyed the gibbon's natural habitat. On top of that, Hainan gibbons frequently fall victim to poachers who sell them for food and traditional medicine or as pets. Currently, the species and its habitat are protected under law, but that's not enough to truly protect their population.
Something as simple as a disease or natural disaster could completely wipe them out.