Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)

Run by the Society of German Nature Photographers (Gesellschaft Deutscher Tierfotografen), the prestigious annual contest celebrates the best wildlife photography from members in Germany. Here: Landscapes, second place: Florian Smit, “Rainforest” (Danum valley, Borneo). (Photo by Florian Smit/2019 GDT Nature Photographer of the Year)

“This Way Up”. Photographic section portfolio, first prize. A Chinook CH-47 weapon systems operator prepares his aircraft during a training exercise in June 2018. (Photo bu SAC Ed Wright/RAF)

“The arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. It is well adapted to living in cold environments. It has a deep thick fur which is brown in summer and white in winter. It averages in size at about 85.3 cm (33.6 in) in body length, with a generally rounded body shape to minimize the escape of body heat. – Wikipedia. (Photo by Trond Eriksen)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)

The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

A pilot inflates a hot air balloon while taking part in the 38th International Balloon Festival of Chateau-d'oex, Switzerland, 23 January 2016. The festival takes place from 23 to 31 January. (Photo by Vincent Vannay/EPA)