Kumbuka, a male silverback gorilla sits next to the keeper's chalk board in his enclosure at London Zoo, Thursday, January 2, 2014. Home to more than 850 different species, zoo keepers welcomed in the New Year armed with clipboards as they made a note of every single animal. The compulsory annual count is required as part of ZSL London Zoo's zoo license, and every creature, from the tiny leaf cutter ants to the huge silverback gorilla is duly noted and accounted for. (Photo by Kirsty Wigglesworth/AP Photo)

The Virgin of El Rocio is carried by pilgrims during a procession around the shrine of El Rocio in Almonte, southern Spain, May 25, 2015. Every spring hundreds of thousands of devotees converge at a shrine to pay homage to the Virgin del Rocio during an annual pilgrimage which combines religious fervour and festive colour. (Photo by Marcelo del Pozo/Reuters)

Revellers ride during the 54th annual brass band festival in the Serbian village of Guca August 7, 2014. Every year Guca is swamped by thousands of people taking part in the celebration of brass band music. (Photo by Marko Djurica/Reuters)

Chinese women run with a ball on a snow covered field in Shenyang in China's northeastern Liaoning province during International Women's Day on March 8, 2018. International Women's Day is celebrated on March 8 every year and commemorates the movement for women's rights. (Photo by AFP Photo/Stringer)

Indonesian students go to school via a makeshift suspension bridge in Ngemplak, Boyolali regency, Indonesia on November 15, 2017. The lack of access to roads makes students every day to cross the dangerous waterways to go to school. (Photo by Arief Setiadi/Pacific Press/Barcroft Images)

A dog waits to be blessed by a priest outside San Anton Church in Mijas, near Malaga, Spain, January 17, 2017. Hundreds of pet owners bring their animals to be blessed every year on the day of Saint Anthony, Spain's patron saint of animals. (Photo by Jon Nazca/Reuters)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)

A Humboldt penguin stands on weighing scales whilst being photographed by members of the press during a photocall at the annual weigh-in at London Zoo in London, Britain, 24 August 2016. Every animal that is in the zoo is weighed and measured and the statistics recorded so the data can be shared with zoos across the world. (Photo by Hannah McKay/EPA)