Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

Peter Ver Ploeg carries Virginia Petrovek through the mud pit during the North American Wife Carrying Championship, Saturday, October 8, 2016, at the Sunday River Ski Resort in Newry, Maine. (Photo by Robert F. Bukaty/AP Photo)

A youth in make-up waits for the start of the annual Zombie walk in Mexico City, Saturday, October 22, 2016. Hundreds dressed in rags and ghoulish makeup to look bloody and decaying, gathered in the historic center of Mexico's capital. (Photo by Christian Palma/AP Photo)

“We take rusty old junk and we put love into it”. The old Motor City has a unique style in bicycles these days: from fat wheels and fake fuel tanks to stretched cycles with powerful sound systems – and even a family-sized BBQ. “Detroit’s custom bike scene developed alongside Slow Roll, a weekly cycle ride started in 2010 by Jason Hall and Mike MacKool. Now upwards of 2,000 people turn up each Monday to cruise a different part of the city. The week I go the crowd seems evenly split between black and white, male and female, city and suburbs. It’s the most inclusive cycle event I’ve ever witnessed”. (Photo by Jason Walker/Slow Roll Monday Nights)

Spanish soldiers of the 7th Airborne Light Infantry Brigade “Galicia” fire a howitzer Light Gun L118 during maneuvers with other units in preparation to NATO's Very High Readiness Joint Task Force (VJTF) in Zaragoza, Spain, April 19, 2016. (Photo by Javier Cebollada/EPA)

Girls watch a procession during the “Fiesta de las Palancas” celebration to ask for blessings and abundance during the new year in Panchimalco, El Salvador, January 5, 2017. (Photo by Jose Cabezas/Reuters)

Situated 10km outside Nairobi city centre, this private giraffe sanctuary is centred around a colonial manor house named Giraffe Manor. Living within the grounds is a herd of rare Rothschild giraffe. The giraffes visit twice a day searching for food, before returning to the forest. Although still wild animals, they have become accustomed to receiving treats from residents and guests. (Photo by Klaus Thymann)

A wolverine is pictured during its first public appearance at the Animal Park of Sainte-Croix in Rhodes, eastern France on January 28, 2016. (Photo by Frederick Florin/AFP Photo)