In this photo taken on Monday, January 5, 2015, a mallard duck attempts to walk on a frozen pond in Yukon, Okla. (Photo by Steve Gooch/AP Photo/The Oklahoman)

A handout image released by the Taronga Zoo shows Veiled Chameleon hatchlings at Taronga Zoo in Sydney, Australia, 11 March 2015. Taronga has welcomed more than 20 baby chameleons, with the last of three clutches of eggs hatching this week. Veiled Chameleons, or Chamaeleo calyptratus, are native to Saudi Arabia and Yemen and can live up to five years. (Photo by EPA/Taronga Zoo)

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)

This bat gives a cheeky smile as he gobbles down his food at Singapore Zoo, on September 10, 2013. (Photo by Benny Iskander/HotSpot Media)

Karis, a one month old lion cub being weighed at Blair Drummond Safari Park near Stirling, Scotland, Thursday October 10, 2013. Weighing in at 5kg, the cub will stay with her mother, Teekay until she is 12 weeks old before they are returned to the pride. (Photo by Andrew Milligan/AP Photo/PA Wire)

A brown capuchin monkey holds a fruit in the Botanic Garden of Rio de Janeiro, Brazil, on July 5, 2013. (Photo by Pablo Porciuncula/AFP Photo)

A sloth peeks out from behind a door on a floating house in the “Lago do Janauari” near Manaus, Brazil, Tuesday, May 20, 2014. Manaus is one of the host cities for the 2014 World Cup in Brazil. (Photo by Felipe Dana/AP Photo)

Alpacas peek out of their box in Kielnarowa, Poland, June 11, 2014. A total of 35 female and 3 male alpacas were imported from Chile by the Rzeszow University of Information Technology and Management Center Zoo to be used for the therapy of children. Alpacas also provide one of the most expensive wools. (Photo by Darek Demanowicz/EPA)