Photo: Roland Weihrauch/AFP/Getty Images
A young Siberian tiger swims in a pool covered in algae on Jan. 7 inside its outdoor enclosure at the zoo in Duisburg, Germany.
Photo: Kazuhiro Nogi/AFP/Getty Images
Japanese macaques rest in an open-air hot spring as snow falls on Dec. 10 at the Jigokudani Monkey Park in Yamanouchi, Nagano, Japan. The macaques, commonly referred to as "snow monkeys," boast a population of about 160 and are a popular tourist draw.
Photo: Vanderlei Almeida/AFP/Getty Images
A brown bear eats a watermelon and cools down in a pool on Jan. 9 at the zoo in Rio de Janeiro, Brazil.
Photo: Horst Ossinger/AFP/Getty Images
A dog carries a large branch in his mouth while swimming in the floodwaters of the Rhine on Dec. 26 in Duesseldorf, Germany.