Two black bear cubs look down from a tree in a residential area of Kingston Township, Pa. on Thursday, October 30, 2014. A mother bear and four cubs were found playing in the tree off of East Center Street. Despite a police officer's efforts to keep them in the tree by moving the car closer to the tree and honking the horn, all five bears climbed down and took off into the woods. (Photo by Andrew Krech/AP Photo/Citizens' Voice)

Two black bear cubs pause as they climb a tree in a residential area of Kingston Township, Pa. on Thursday, October 30, 2014. (Photo by Andrew Krech/AP Photo/Citizens' Voice)

Veterinarians prepare Tango, an eleven-year-old male jaguar, for a full medical examination at the Buenos Aires Zoo October 27, 2014. Argentina's rare jaguar was added to Buenos Aires Zoo's DNA bank on Monday as conservationists step up efforts to save the big cat species that is on the brink of extinction. The 11-year-old jaguar called Tango could be the key to preserving the species for future generations. At the zoo's Biotechnology Reproduction Lab, vets took blood, hair and semen samples from Tango to be stored. (Photo by Enrique Marcarian/Reuters)

Veterinarians insert a tube inside the mouth of Tango, an eleven-year-old male jaguar, during a full medical examination at the Buenos Aires Zoo October 27, 2014. (Photo by Enrique Marcarian/Reuters)

Miss Chinese winners (L-R) He Wenqian, Liu Zhongqing and Yang Xue pose for pictures with Giant Panda triplets at the Chimelong Safari Park in Guangzhou, Guangdong province, October 27, 2014. (Photo by Reuters/Stringer)

A white-headed capuchin monkey is seen in a cage during a news conference in San Salvador October 29, 2014. Authorities of the Ministry of Enviroment of El Salvador rescued about 100 endangered animals abandoned in a dumpster near the border with Honduras on Wednesday morning, local media reported. More than 90 turtles, monkeys and parrots were found in plastic bags ready to be smuggled into Salvadorean territory. (Photo by Jose Cabezas/Reuters)

A white-headed capuchin monkey is fed during a news conference in San Salvador October 29, 2014. (Photo by Jose Cabezas/Reuters)

A polar bear eating from a Halloween pumpkin at the Schoenbrunn Zoo in Vienna, Austria, October 27, 2014. (Photo by Daniel Zupanc/EPA)

White whale or beluga Zhuoya gives birth to her first offspring at an aquarium in Changsha, Hunan province, October 29, 2014. (Photo by Reuters/China Daily)

White whale or beluga Zhuoya gives birth to her first offspring at an aquarium in Changsha, Hunan province, October 29, 2014. (Photo by Reuters/China Daily)

White whale or beluga Zhuoya swims with her calf after its birth at an aquarium in Changsha, Hunan province, October 30, 2014. (Photo by Reuters/China Daily)

A giraffe eats in front of the Sydney Opera House during feeding time at Taronga Zoo October 31, 2014. (Photo by David Gray/Reuters)

A Western Lowland Gorilla sits in its enclosure at Sydney's Taronga Zoo October 31, 2014. (Photo by David Gray/Reuters)

Two deer spar with their antlers at Kenilworth Aquatic Gardens in Washington, DC, USA, 30 October 2014. Fall foliage is near peak color in the DC region. (Photo by Jim Lo Scalzo/EPA)

An undated handout picture made available by the University of the Sunshine Coast on 29 October 2014 shows a koala to be vaccinated in Maroochydore, Queensland, Australia. Scientists at the University of the Sunshine Coast have spent five years working on vaccine for chlamydia the sexually transmitted disease which is devastating koala populations and causing blindness and infertility. (Photo by EPA/University of the Sunshine Coast Australia and New Zealand)

An snow leopard (Panthera uncia) is pictured at the Chapultepec Zoo, in Mexico City, on October 27, 2014. The snow leopard is a large cat native to the mountain ranges of Central and South Asia. (Photo by Ronaldo Schemidt/AFP Photo)

A pelican is pictured on October 29, 2014 at the zoo in Frankfurt am Main, western Germany. (Photo by Boris Roessler/AFP Photo/DPA)

Salmon attempt to leap up the fish ladder in the river Etterick on October 27, 2014 in Selkirk, Scotland. The salmon are returning upstream from the sea where they have spent between two and four winters feeding with many covering huge distances to return to the fresh waters to spawn. (Photo by Jeff J. Mitchell/Getty Images)

A camel herder stands beside resting camels at the annual cattle fair in Pushkar, in the western Indian state of Rajasthan, Wednesday, October 29, 2014. Pushkar, located on the banks of Pushkar Lake, is a popular Hindu pilgrimage spot that is also frequented by foreign tourists who come to the town for the annual cattle fair and camel races. (Photo by Deepak Sharma/AP Photo)

A Western Lowland Gorilla named Mbeli holds her baby in their enclosure at Sydney's Taronga Zoo October 31, 2014. The baby gorilla was born three days ago, and is the first sired by the zoo's new Silverback who arrived from France in 2012. (Photo by David Gray/Reuters)

Children inside a cage watch at close quarters a lion at the Safari Lion Zoo in Rancagua, Chile, on October 30, 2014. the Safari Park Zoo is the only park in Latin America where tourists can see from a short distance six lions in a two-hectares open area. (Photo by Martin Bernetti/AFP Photo)

Top view of a lion on the cage of a vehicle at the Safari Lion Zoo in Rancagua, Chile, on October 30, 2014. (Photo by Martin Bernetti/AFP Photo)

Hundreds of festive, adorable canines and their owners took part in the annual “A Very Corgi Howloween” costume walk Saturday, October 25, 2014, at Green Lake in Seattle, Wash. The walk was put on by the Seattle-local “Corgi's R Us” MeetUp group. (Photo by Jordan Stead/AP Photo/Seattlepi.com)