About 90% of organisms that once walked the planet do not exist today. Though extinction is a natural phenomenon, humans have accelerated the process by destroying natural habitats, climate change, poaching, diseases, and the introduction of invasive species. About 20,000 species of animals and plants are staring at extinction, including a quarter of the known mammals. Many species become extinct even before they are discovered, while many more have become extinct in the natural environment and exist only in captivity or depend on humans for survival.
The scimitar-horned oryx or the Sahara oryx was once found throughout the Sahara, but the wild population became extinct in 2000 as a result of poaching and climate change. The few breeding individuals in captivity are found in Senegal, Morocco, Tunisia, and the Texas Hill Country. A reintroduction program seeks to reintroduce the animals back into the wilderness of Chad and Tunisia. Ancient Egyptians domesticated the species as sacrificial to the gods.
New Guinea Singing Dog
Scientists are uncertain whether the New Guinea singing dog was wild or domestic, but it is unique from other canines and has a distinct genetic code. The species did not receive much attention in the late 19th century because it was considered feral and of little significance to humans. The dog has not been sighted in the wild since the 1970s, but a few are found in zoos around the globe. Unfortunately, inbreeding has distorted their genetic pool, and it is unclear whether the species can survive in the wild.
Kihansi Spray Toad
The Kihansi spray toad inhabited the spray zone of two waterfalls in Tanzania and relied on the water spray to keep them moisturized. After the government constructed dams upstream, the spray declined by over 90% resulting in the death of the toads. Conservationists tried saving the species by introducing a sprinkler system but accidentally introduced a deadly fungus that wiped out the total population. Fortunately, some of the toads were captured and kept in captivity. Though they have bred successfully, there are no immediate plans to reintroduce them to the wild.
The Micronesian kingfisher was a native species of Guam. They suffered from island tameness since they did not have any natural predators. During the Second World War, brown tree snakes were introduced at the peril of the birds. Their population began to drop drastically without any definite explanation until 1983 when researchers pinpointed the snakes as the culprits. By then, the snake population had grown significantly, and researchers had no choice but to capture the remaining 29 birds and breed them in zoos.
The Guam rail suffered the same fate as the Micronesian kingfisher. The species evolved in the absence of natural predators and was unable to cope with the introduction of the brown tree snake during the Second World War. Some of the birds were captured and successfully bred in zoos. After 20 years, they were introduced to the Rota island of Northern Mariana Islands under keen supervision from conservationists. About 17 zoos participate in the reintroduction program to establish a viable wild population.
Black Softshell Turtle
The black softshell turtle is a freshwater turtle that inhabited the Brahmaputra River in India and Bangladesh. The species was thought to be extinct until a small number was found inhabiting a man-made pond in Chittagong. In 2012 two other populations were discovered in Assam and Bhoroli River in India. Approximately 500 individuals live in wild protected habitats where researchers and conservationists keep track of their progress.
Père David's Deer
Père David's deer is native to the marshy river valleys of China. It was declared extinct in the wild in 2008 but has since been reintroduced to some protected areas. It is the only surviving species of the genus Elaphurusbut is closely related to the genus Cervus. There are about 53 herds in China, where they are closely monitored for disease and predation with the intent to grow the numbers to a free-ranging population.
The Socorro dove was a native species of Socorro Island, Mexico. The wild population was decimated by feral cats and destruction of the natural habitat for sheep rearing. The last bird was seen in 1972, but approximately 100 birds are kept in captivity, of which less than 100 are purebred. Most of the birds have been bred with the mourning dove.