6 species we might have to say goodbye to in 2015

Sumatran Elephant

The smallest of the Asian elephants, the Sumatran elephant's numbers have declined by an astonishing 80% in less than 25 years due to deforestation, habitat loss and human-elephant conflict in Sumatra. Around 2,400 to 2,800 individuals survive today.

Male Asian elephants have relatively small tusks, but poachers still kill to sell them in the illegal ivory market, thus skewing the sex ratio among wild elephants and making future breeding and species survival difficult.

Leatherback Turtle

The largest sea turtle species and one of the most migratory, the Leatherback turtle population has severely declined in recent years due to overharvesting, fisheries bycatch, plastic ingestion, egg poaching, habitat loss and expansion of coastal development that continues to disturb and destroy turtle nesting beaches.

SAOLA

Known as the Asian unicorn, the saola is rarely seen in the wild, and none live in captivity. The current population is estimated to be between a few dozen and a few hundred. Saola are hunted to supply growing demands for traditional medicine in China and food markets in Vietnam and Laos.

Habitat loss and reduced genetic diversity also threaten this species' already dwindling population.

Vaquita

As the world's most rare marine animal, the vaquita is on the brink of extinction with fewer than 100 individuals left in the world.

Found in the upper Gulf of California, one out of every five vaquita gets entangled and drowned in gillnets that are intended to catch another critically endangered species, the totoaba, whose swim bladders are illegally sold for about $4,000 a pound.

As long as this illegal international trade thrives, the vaquita population will continue to decline.

Sumatran Orangutan

Orangutan habitats in Sumatra are depleting at an astonishing rate due to forest fires, development of oil palm plantations, illegal logging and other agricultural development, posing a serious risk to this species.

Hunted for food and even captured alive to be kept as status symbols, this species is facing a downhill spiral due to inadequate law enforcement and an increase in illegal trafficking. About 7,300 individuals are left in the wild.

Yangtze Finless Porpoise

Known as the "giant panda of the water," these clever creatures are one of the most famous species found in China's Yangtze River, the longest river in Asia.

Due to overfishing, decrease in food supply, pollution and changing conditions caused by dams, only 1,000 to 1,800 individuals remain. The finless porpoise's close cousin, the Baiji dolphin, has already been declared functionally extinct due to human activity.