A hyena eyes a herd of zebra at Lake Nakuru National Park, Kenya, August 19, 2015. The Park is home to some of the world's most majestic wildlife including lions, rhinos, zebras and flamingos. The scenery is stunning, from forests of acacia trees to animals congregating at the shores to drink. UNESCO says that with rapid population growth nearby, the area is under "considerable threat from surrounding pressures," particularly deforestation, a contributing factor in floods. (Photo by Joe Penney/Reuters)

Kia Vue of St. Paul sports long nails at the Minnesota Hmong New Year celebration Saturday, November 29, 2014, at the Saint Paul RiverCentre in St. Paul, MN. The annual Minnesota Hmong New Year celebration will be held at the Saint Paul RiverCentre November 28–30. Hmong New Year has a deep cultural significance to the Hmong community. It is a celebration of accomplishments during the past year and a time to welcome a new beginning. (Photo by David Joles/Star Tribune)

Visitors watch a tree decorated with about 10,000 Easter eggs in the garden of the retired couple Christa and Volker Kraft in Saalfeld, central Germany, Tuesday, March 19, 2013. The Kraft family has been decorating their tree at Easter for more than forty years. (Photo by Jens Meyer/AP Photo)

The President tree is the name of a giant sequoia located in the Giant Forest of Sequoia National Park in the United States, east of Visalia, California. The tree is believed to be at least 3,200 years old.
The tree was named after President Warren G. Harding in 1923. Nearby trees include Chief Sequoyah, the 27th largest giant sequoia in the world, and the Congress Group, two dense stands of medium sized sequoias that represent the "House" and "Senate".

Korean Air flight attendants photograph a therapy dog dressed in a Superman Halloween costume, as part of a program to de-stress passengers at the international boarding gate area of LAX airport in Los Angeles, California, United States, October 27, 2015. (Photo by Lucy Nicholson/Reuters)

Australian Aboriginal hunter Marcus Gaykamangu of the Yolngu people, carries an Australian native lizard called a goanna over his shoulder as he walks away from a billabong near the “out station” of Yathalamarra, located on the outksirts of the community of Ramingining in East Arnhem Land November 22, 2014. (Photo by David Gray/Reuters)

Model Helen Kwok displays the nail art completed by a competitor at the Canada Nail Cup in Vancouver, Monday, February 16, 2015. Nail artists competed in multiple categories at the event, which according to organizers is the only nail competition in the country. (Photo by Darryl Dyck/AP Photo/The Canadian Press)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)