1. A pet saddleback tamarin hangs onto his owner as she takes a dip in the Yomibato River, deep inside Peru's Manu National Park.
2. On this mountainside in Yosemite National Park, Steven Wilkes took 1000 images over 26 hours to create this day-to-night composite.
3. As a storm lights up the evening sky over Wood River, Nebraska, about 400,000 sandhill cranes arrive to roost in the shallows.
4. This 16-year-old panda, known as Ye Ye, lounges in a wild enclosure at a conservation center in China's Wolong Nature Reserve.
5. In just inches of water, blacktip reef sharks wait for the tide to come in and refill the lagoon Seychelles’ Aldabra Atoll.
6. Hundreds of silversides swirl through some mangroves in Cuba.
7. A baby African white-bellied tree pangolin hitches a ride on its mother's back at the Pangolin Conservation Center in St. Augustine, Florida.
8. These tortoises fight for shade from the sun. If they don't get adequate shade, they will cook in their shells.
9. Blood drips from a Rüppell’s vulture’s beak.
10. A grizzly bear, in Grand Teton National Park, fends off ravens from a bison carcass.
11. The colors of Grand Prismatic Spring in Yellowstone come from thermophiles: microbes that can thrive in scalding water.
12. This drowned bison became a tasty feast for this wolf and her 2-year-old offspring.
13. A young Rüppell’s vulture tucking into a zebra in the Serengeti.
14. Yellowstone's Grand Canyon
15. A diver keeps a close eye on a tiger shark in the Bahamas.
16. Steven Donovan (pictured) took a seasonal job at Glacier National Park in order to improve his photography skills.
17. These rhinos on a South African ranch have recently had their horns trimmed. Unlike elephant ivory, rhino horn grows back when cut properly.
18. An American crocodile rises from the depths.
19. On their first migration to their summer range in southeastern Yellowstone, three-week-old calves of the Cody elk herd follow their mothers up a 4,600-foot slope.
20. A harvested bull elk and its antlers are transported the old fashioned way - by mule.
21. Igor Voronkin surfaces at the Barentsburg coal mine on Spitsbergen, in Norway’s Svalbard archipelago. Like most of the 400 workers, he’s from eastern Ukraine.
22. A refugee family lives amid the rubble in Ramadi, an Iraqi city leveled by ISIS’s destruction.
23. Twilight bathes the sanctuary of Athena Pronaia at Delphi.
24. In order to track changes in sea ice, this Norwegian vessel drifted along with it for a period of 5 months.