Case studies illustrate how close some species are to going extinct

Rhinos

The world has known 11 subspecies of rhino. The western black rhino was declared extinct in 2011.

Another, the northern white rhino, was down to just six specimens before one of the last two males died in October, possibly of old age. The remaining one has armed guards. The last truly wild specimens have all been killed by poachers.

“Consequently, the species now stands at the brink of complete extinction,” said an announcement by the Ol Pejeta Conservancy in Kenya, where three of the rhinos remain.

The International Rhino Foundation says all rhino species are under the threat of extinction. There are fewer than 60 Javan rhinos, about 200 Sumatran, about 2,800 Indian, about 4,240 black and about 18,000 white rhinos left.

Poachers killed 1,215 rhinos in South Africa alone in 2014, or an average of more than three a day. That was a 21 percent increase from 2013. Prior to 2007, only 10 to 15 rhinos were poached a year in South Africa.

The World Wildlife Fund warns that if the rate of increase continues, African rhinos could be extinct in a decade or two.

Poachers are tempted primarily by Asian demand for rhino horn and its supposed medicinal qualities. Poachers take the horn and leave the carcass to rot. International trade in rhino horn has been banned since 1977 but, increasingly, poaching has been dominated by armed criminal syndicates.

Tigers

An estimated 100,000 tigers prowled the wild 100 years ago. Now estimates are fewer than 4,000. According to the Association of Zoos and Aquariums, four subspecies (Bali, Caspian, Javan and South China) have disappeared from the wild in the last century.

The Amur, Malayan and Sumatran tiger subspecies are endangered, with fewer than 500 each thought to remain in the wild. The main threats are loss of habitat, poaching, loss of prey and interaction with humans. Tigers are thought to now occupy less than 7 percent of their original range.

“Most tiger populations are small and isolated,” the AZA reported, “and it is likely that many of these populations are losing genetic diversity.”

Tara Harris of the Minnesota Zoo returned from assessing the problem of tiger-human conflicts in Sumatra last month. The cats may take livestock at night or leave tracks near villages, creating fear and human backlash.

Conservationists promote support teams as an alternative.

“Everybody has cellphones, and they call response teams if they spot a tiger to help push them back into the forest,” said Harris. “We also help people make tiger-proof livestock enclosures so they can bring their cattle or buffalo in at night.”

Harris said one area of Sumatra that used to average 15 tigers killed a year has brought the number down to zero.

“I don’t think they are inevitably headed for extinction,” Harris said. “There are some pretty large protected areas in Sumatra that hold a lot of promise for them, and if we can stop the poaching, then I think there’s good opportunities at least to keep the populations stable.”

Elephants

Both African and Asian elephants are listed as endangered because of loss of habitat and poaching.

One estimate puts the number of African elephants 350 years ago at 27 million. The population nosedived by more than 90 percent in the 20th century. There are now roughly 400,000 left, and about 9 percent of them are being killed every year for their ivory tusks.

A United Nations assessment found the number of African elephants killed jumped from 25,000 in 2011 to 32,000 in 2012. That’s more than all the Asian elephants left in the wild.

The Guardian newspaper reports that, despite an international ban on ivory trade, there are still dozens of ivory-carving factories in China, where it is a status symbol. China’s affluence is priming the black market demand. A one-time legal sale to China in 2008 has made it difficult to distinguish legal ivory from illegal ivory, complicating enforcement.

The National Geographic reports a single tusk can bring $175,000 in Asia.

In addition, rebels and terrorists in war-torn Africa reportedly are now bartering ivory for weapons, creating another stimulus for the trade. Poachers are using helicopters and night vision goggles to hunt their defenseless prey. Ground crews then move in with chainsaws.

“Tusks on the market are getting smaller,” The Atlantic reported, “because the elephants are dying younger.”

This story was originally published May 16, 2015 at 4:48 PM with the headline "Case studies illustrate how close some species are to going extinct."