The Atlantic Puffin is definitely a curious-looking bird. The special coloring that this bird develops for the breeding season in the spring is very reminiscent of tropical birds. The bright colors of the beak and the markings around the eyes serve no particular advantage and have evolved as a result of sexual selection. However, Puffins don’t look that pretty all year round. They shed all these festive colors in partial moult after the breeding season is over. They lose the ornaments around their eyes, their face becomes darker, and their beak becomes very different. The natural habitat of these birds is the cold waters of the North Atlantic Ocean.

These otherworldly images give a rare glimpse inside caves barely ever seen by the human eye. With its peculiar pools of water and strange colored sediments, the bizarre looking tunnels of the Shakuranskaya cave could be a set straight out of a science fiction film. Found in the disputed region of Abkhazia, around 75 miles outside of Sochi, Russia, it is rumored the incredible underground chambers were formed after a huge earthquake struck the area in 1892. After causing part of a nearby mountain to collapse into the Amtkel River, it is thought the dam-like affect has created a series of interconnecting underground tunnels. Here: a large pool of water inside one of the tunnels. (Photo by Vladimir Mulde/Caters News)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

We place too much value into something as elusive as time. This is the lesson that Arina Pozdnyak, the creator of Perpetual Calendar, is trying to teach us. Days fly by, and even months are mere speckles of sand in an hourglass of eternity. People do not realize that the time given to us by fate cannot be measured using months or even years. It is measured using emotions and impressions. If a person lives to be 150 years old without experiencing any emotions, he might as well have lived one day, for all it’s worth. On the other hand, a person who lived an exciting, fulfilling life, read countless books and cherished every moment that he had, is actually the one who lived a longer life, even if in reality his flame was snuffed out much too soon. (Photo by Arina Pozdnyak)

The Yakutat Glacier is seen during a flight over southeastern Alaska near the town of Yakutat, October 7, 2014. (Photo by Bob Strong/Reuters)

“Adventurers have gone deep underground to discover previously unexplored caves in these pictures. The awe-inspiring snaps show the cavers dwarfed by the huge series natural rock chambers in the Leye – Fengshan Geopark, China. Belgian photographer Francois-Xavier De Ruydts, 33, captured the team of explorers as they trekked through the deep wonderground in January 2014”. – Caters News. Here: Caving expedition in Fengshan, China, Guangxi province. (Photo by Francois-Xavier De Ruydts/Caters News)