A man tries to stop two bulls from locking horns during a bullfight in the eastern emirate of Fujairah October 17, 2014. There are no matadors or picadors, but bulls locking horns with each other draw big crowds to bullfights in the United Arab Emirates (UAE). An hour's drive from the dancing water fountains of Dubai's glitzy downtown, hundreds of fans gather in Fujairah to watch bulls fighting, or perhaps more accurately head butting, with honour rather than money at stake. The UAE sport involves two bulls locking horns in a three-to-four minute Sumo-wrestling-like fight that usually ends with no bloodshed. (Photo by Ahmed Jadallah/Reuters)

A young boy plugs his ears as his sister (C) and nanny (L) watch from Gravelly Point Park as planes land at Reagan National Airport in Arlington, Virginia on June 29, 2017. President Donald Trump' s travel ban on people from six mostly Muslim countries will come into force late Thursday, as controversy swirls over who qualifies for an exemption based on family ties. (Photo by Jim Watson/AFP Photo)

A sadhu, or a Hindu holy man, blesses a devotee as he smokes marijuana at a transit camp on the way to Gangasagar, in Kolkata, India, Sunday, January 7, 2018. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan. 14. (Photo by Bikas Das/AP Photo)

Khansa, an eight month old critically endangered Bornean orangutan shows off it's two front-teeth, at the Singapore Zoo on Thursday, January 11, 2018 in Singapore. The Singapore Zoo is active with its breeding programs as part of its wildlife preservation efforts. This is the Zoo's 46th successful orangutan birth. (Photo by Wong Maye-E/AP Photo)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Prints of R$ 50 Brazilian reais bills sit on a table for inspection at at the Casa da Moeda, the national mint, in the Santa Cruz suburb of Rio de Janeiro, Brazil, on Tuesday, March 5, 2013. Brazil is likely to keep its key interest rate at a record low for the third straight meeting, as policy makers are caught between a fragile economic recovery and faster-than-expected inflation. (Photo by Dado Galdieri/Bloomberg)

A cat tries to find dry ground around an apartment complex in Houston after Hurricane Harvey hit on Aug. 30. Harvey made landfall in South Texas on August 25, leading to days of downpours that dumped more than 50 inches of rain. Harvey damaged or destroyed about 200,000 homes as the storm system flooded much of Houston and smaller coastal communities. (Photo by Scott Olson/Getty Images)