A miner with a donkey makes his way through the low and narrow tunnel leading out of a coal mine in Choa Saidan Shah in Punjab province, April 29, 2014. Workers at this mine in Choa Saidan Shah dig coal with pick axes, break it up and load it onto donkeys to be transported to the surface. Employed by private contractors, a team of four workers can dig about a ton of coal a day, for which they earn around $10 to be split between them. The coalmine is in the heart of Punjab, Pakistan's most populous and richest province, but the labourers mostly come from the poorer neighbouring region of Khyber Pakhtunkhwa. (Photo by Sara Farid/Reuters)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

Savita, a street performer, helps her dog to balance on empty tin containers as they perform at a roadside in Ahmedabad September 7, 2014. (Photo by Amit Dave/Reuters)

In this April 16, 2015 photo, costume jewelry is on display for sale at al-Aqeeliya open-air auction market in Riyadh, Saudi Arabia. A man came with the suitcase full of beaded jewelry and sold the whole bag to the auction winner, who had just a few moments to inspect its contents before buying. (Photo by Hasan Jamali/AP Photo)

A baby bush-baby in a set of scales at London Zoo shortly after birth. (Photo by Fox Photos/Getty Images). 10th August 1938

These Eurasian Otters seem ready for any danger as they all stand up on thier hind legs alert to any threats near to the English river bank. Amateur photographer and retired MOD worker Tony Moir, 57, spotted the otters whilst looking for kingfishers to photograph near the river Trent in East Yorkshire, UK. He was able to take just a couple of pictures before the excited animals spotted the photographer and ran away. (Photo by Tony Moir/Solent News)

A cat and a seagull feeding on a street in Heybeliada, the second largest of the Prince Islands in the Sea of Marmara, near Istanbul, Turkey on February 01, 2017. (Photo by Sebnem Coskun/Anadolu Agency/Getty Images)

Take me away, deer, Russia. The Nenet people of Arctic Russia use reindeer and sledges as a prime mode of transport. The animals’ navigational ability means that in severe conditions they are sometimes the only hope of survival. (Photo by Kamil Nureev/Smithsonian Photo Contest)