A man smiles as he carries firewood he bought on a street amid ongoing fuel and cooking gas shortages in Yemen's capital Sanaa December 2, 2015. (Photo by Khaled Abdullah/Reuters)

An Afghan refugee girl shows her younger brother a calf in a slum on the outskirts of Islamabad, Pakistan, Friday, February 6, 2015. (Photo by Muhammed Muheisen/AP Photo)

Children beg for alms in a street on August 11, 2014 in Manila, Philippines. The Philippines has one of the fastest growing populations in Southeast Asia with around 100 million people. At least 12 million people live in the capital city of Manila alone, making it one of the most densely populated and largest cities in the world. Lack of space and economic opportunities has pushed around four million people to live informally along waterways, bridges and even cemeteries further straining the already weak infrastructure and straining the resources of the city. (Photo by Dondi Tawatao/Getty Images)

A man and his dog wade through a flooded road in Vila Velha, Espirito Santo state, Brazil, on December 27, 2013. At least 44 people have died and more than 60,000 have been left homeless following torrential rains over the past few weeks in southeast Brazil. (Photo by Yasuyoshi Chiba/AFP Photo)

Dogs perform during “Stars and starlets”, a new programme, at the National Circus in the Ukrainian capital of Kiev April 30, 2015. (Photo by Gleb Garanich/Reuters)

Competitors release their hens during the World Championship Hen Racing Championships in Bonsall, Britain August 1, 2015. (Photo by Darren Staples/Reuters)

The British and Irish Association of Zoos and Aquariums (BIAZA) has announced the winning images in its annual photography competition. The 2020 winners show the important work of zoos and aquariums at an immensely challenging time. After months of closures, these conservation organisations are reeling from the financial impacts of the coronavirus pandemic. Here: Runner-up, Heart and Minds: Nifty nose, by Samantha Allworthy at Longleat. Species: prehensile tailed porcupines. (Photo by Samantha Allworthy/BIAZA 2020 Photography Competition)

Four year old Kaleb Stanley (R), from Dublin, reaches up to puncture a giant bubble with the help of his seven year old brother Jacob on London's South Bank on May 9, 2008 in England. (Photo by Peter Macdiarmid/Getty Images)