The Spanish photographer Xavi Bou digitally combines sequential pictures of birds to create a single image, or chronophotograph, that reveals the shapes of their flight paths against Catalonian skies. His work shows the variety and beauty to be found in the daily activities of the local birds, including spiralling storks, swooping starlings and giddy swifts. Here: European herring gulls at Llobregat Delta. (Photo by Xavi Bou/Rex Features/Shutterstock)

Football transfers are not cheap. To have a player strengthen their ranks, teams are willing to pay big money. The football transfer considered to be the most expensive in the sport's history was that of Gareth Bale leaving Tottenham to play at Real Madrid. The Spanish club paid not less than £86 million (about $133 million at today's exchange rates) to have the player among its own. But recent news suggest that this record might be broken this year. According to reports in the media, UK Premier League team Manchester United is willing to almost double that amount.

A woman carries a water pump to work on February 11, 2017 in Almolonga, Guatemala. The Mayan town in the western highlands district of Quetzaltenango has surged in prosperity in recent years with high-productivity vegetable farming, exporting much of its excess crops to neighborning El Salvador. (Photo by John Moore/Getty Images)

Cameron Shonnard backflips a jump at Squaw Valley in Olympic Valley, California, December 5, 2015. An El Nino is forecasted for California, and regular precipitation has been welcomed after years of drought. (Photo by Max Whittaker/Reuters)

Graffiti saying “justice” partially seen above flood waters in Asuncion, December 27, 2015. More than 100,000 people have had to evacuate from their homes in the bordering areas of Paraguay, Uruguay, Brazil and Argentina due to severe flooding in the wake of heavy summer rains brought on by El Nino, authorities said on Saturday. (Photo by Jorge Adorno/Reuters)

Nelson Hernandez flashes the victory sign as he shows off one of the voodoo dolls that he is selling at El Viejo Lazaro Botanica to try and help the Miami Heat fans root their team on against the Dallas Mavericks in the NBA finals on June 9, 2011 in Miami, Florida. The dolls made from cotton come in white or black and they are all the same size. The user of the doll must have the name of the player attached to the doll, which is filled with cotton, herbs, sticks and a special powder. (Photo by Joe Raedle/Getty Images)

A baboon clings to the leg of an internally displaced boy at a camp on the outskirts of the town of Qol Ujeed, on the border with Ethiopia, Somaliland April 17, 2016. Across the Horn of Africa, millions have been hit by the severe El Nino-related drought. In Somaliland and its neighbouring, also semi-autonomous, Puntland region, 1.7 million people are in need of aid, according to the United Nations. In Somaliland itself, the most affected areas include the northwest Awdal region bordering Ethiopia. (Photo by Siegfried Modola/Reuters)