Going toe-to-toe, these fighting primates could give Floyd Mayweather a run for his money. The amazing images – captured by Australian tourist Julie Rathbone on the banks of the Zambezi river in Africa – show the pair engaging in a few fisticuffs. The Chacma baboons appeared to settle a disagreement by fighting – before a senior baboon plays referee and steps in to break it up. Nurse unit manager Julie Rathbone, 59, from New South Wales, was on a cruise down the river when she spotted the fracas unfolding. (Photo by Julie Rathbone/Caters News)

A young oriental small-clawed otter at the zoo in Neumuenster, Germany, March 5, 2014. The six young otters (one male, five female) were born on December 7, 2013. (Photo by Maja Hitij/EPA)

The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

In this Thursday, April 16, 2015 photo provided by Robert MacFarlane, a raccoon climbs up a skyscraper in downtown Toronto. Social media was abuzz Thursday with the photo of the raccoon peering from between the metallic rungs of a crane 58 stories high. (Photo by Robert MacFarlane)

Winner of the National Park Foundation's photo contest; Honorable Mention: Fan Favorite. Grand Canyon National Park, Arizona. Three friends enjoy sunrise over the Grand Canyon. (Photo by Peter Blanchard)

Renowned aerobatic pilots Sean D. Tucker, flying the Oracle Challenger III, and Jeff Boerboon, flying the Jack Link's Screamin' Sasquatch, take to the skies over EAA's 2015 AirVenture Oshkosh, on Monday, July 20, 2015 in Oshkosh, Wis. (Photo by Matt Ludtke/AP Images for Jack Link's)

A hyena kisses his own reflection while appearing to walk on water. (Photo by Jake De Wet/Caters News Agency)

Undated handout issued by Take A View of Sunrise at Winnats Pass, Derbyshire, England which won the Visit Britian “You're invited” Award for the best image from an overseas entrant category in this year's Landscape Photographer of the Year Awards. (Photo by Sven Mueller/PA Wire)