Animals Shark and Orangutan Species Move Closer to Extinction Whale sharks, winghead sharks and Borneo orangutans are considered endangered.

Whale sharks, winghead sharks and Bornean orangutans are on a downward slide toward extinction, according to new assessments by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The global organization has just listed the two sharks as "Endangered" and the primate as "Critically Endangered," with calls for urgent conversation actions to save all three. "These new IUCN Red List assessments emphasize how urgent it is for the conservation community to act strategically to protect our planet's incredible diversity of life," said Jane Smart, director of IUCN's Global Species Program, in a press release. "The world's oceans and forests will only continue to provide us with food and other benefits if we preserve their capacity to do so." RELATED: At Risk Species Still on U.S. Menus Numbers of whale sharks (Rhincodon typus), the world's largest living fish, have more than halved over the last 75 years, according to Smart and her team. Many of these peaceful and slow-moving sharks are either intentionally fished by humans or are accidentally killed by ship propellers.

India, the Philippines and Taiwan now prohibit large-scale fishing of whale sharks, but the sharks continue to be fished in other locations, such as in waters off of southern China and Oman. Whale sharks and tuna often co-exist in the same regions, so the sharks are frequently also killed as by-catch by fishermen targeting tuna. "While (the) international whale shark trade is regulated through the species' listing on the Convention on International Trade in Endangered Species (CITES), more needs to be done domestically to protect whale sharks at a national level," said Simon Pierce, lead Red List assessor, who is a member of the IUCN Species Survival Commission (SSC) Shark Specialist Group and is a co-founder of the Marine Megafauna Foundation. RELATED: One in Five Plant Species Threatened with Extinction

Unregulated fishing has also led to the decline of winghead shark (Eusphyra blochii) populations. A type of hammerhead shark, the winghead is vulnerable to entanglement in fishing nets. Some fishermen intentionally catch them too. Precisely how many winghead sharks are still left in the world is unknown because surveys find so few of these sharks now that even coming up with a good estimate is challenging. The Bornean orangutan (Pongo pygmaeus) was moved by the IUCN from Endangered to Critically Endangered, which is the highest extinction risk category. According to the IUCN, the primate's population is declining because the forests this species lives in are being converted into palm oil, rubber or paper plantations. Humans hunt these orangutans as well.