10 animals on the verge of extinction

Polar bears

This one shouldn't surprise you. The polar bear has become the poster animal for the devastating changes global warming is bringing to the Arctic. Polar bears are dying because their range is shrinking; the sea ice they use to hunt seals is melting as temperatures rise. It's estimated that there are 20,000-25,000 polar bears worldwide. Thirty percent of the 19 recognized subpopulations are in decline. (Text: Shea Gunther) 

Lions

It might be too late for lions. The number in the wild has dropped by as much as half in 20 years. Today there are an estimated 16,500 to 47,000 African lions, down from 400,000 in 1950. Their population has been carved up into ever-tightening, isolated ranges. Humans are spreading into these small pockets of space, and instability on the continent isn't conducive to conservation.

Elephants

There are about 500,000 African elephants in the wild. Poachers hunt elephants for their tusks, a relationship that has changed their evolutionary path -- elephants with shorter tusks are breeding more and producing offspring with increasingly stunted tusks. Elephants don't breed until they're teenagers and gestation lasts for 22 months -- creating a population unable to bounce back. 

Tigers

Tigers and humans don't mix well. We hunt them for fur, gallbladders, paws, teeth and tail. Their habitat has been under assault by development over the past few decades. All six remaining subspecies are endangered. Some estimates put the total number of breeding tigers at 2,500 with no subpopulation larger than 250.

 

Cheetahs

Do you recognize any patterns? We're good at killing big cats. Cheetahs are fast, but they might not be able to outrun extinction. The cat that can accelerate faster than a muscle car isn't adaptable to habitat change and has recently suffered from genetic degradation due to inbreeding. It's estimated that about 12,000 cheetahs remain the wild. They have a high infant mortality rate and are losing more habitat every year.

Egyptian vultures

These beautiful, white, well-feathered birds have an average wing span of 5.5 feet and are found in southern Europe, northern Africa, and western and southern Asia. They use tools, dropping rocks onto ostrich eggs to crack the shell. Their thin beaks and long necks let them get carrion larger birds can't reach. However, they are being poisoned by Diclofenac, an anti-inflammatory drug used on domesticated animals. 

 

Mountain gorillas

Of all the animals, I'm most hopeful for the mountain gorillas. They face poaching and loss of habitat, but they also have a lot of support. However, they are pursued by hunters and have been stricken by the Ebola virus. An outbreak between 2002 and 2004 in Gabon and Congo may have killed as many as 5,000 gorillas. Their populations are increasingly isolated, putting them in danger of being picked off by hunters, farmers and disease.  

 

Chinese alligators

While American alligator populations are exploding, their Asian cousins are in danger. There are only about 200 Chinese alligators living in the wild in a handful of ponds along the lower Yangtze River in eastern China. They were pushed out of their habitats by agriculture and the presence of poisoned rats, which the alligators eat. The species is thriving in captivity, with about 10,000 around the world. 

Orangutans

About 62,000 Orangutans live on the Southeast Asian islands of Borneo and Sumatra. Their habitat has been chopped up into smaller, more isolated pockets. Logging, road construction and especially the creation of palm-oil plantations have leveled their habitats, leaving them vulnerable to hunting and kidnapping (to be sold as pets). Like mountain gorillas, orangutans have the benefit of good PR, but that might not be enough.

 

Blue Whales

The world's largest animal is in trouble. Blue whales were nearly hunted to extinction in the early 20th century, and by the time hunting was deemed illegal in 1966, only a few thousand remained, down from a prewhaling population of about 240,000. Today, they are under attack from seas polluted by chemicals such as PCBs and noise from boats and sonar equipment. Add the warming and acidification of the seas, and the outlook is bleak.