This is the Osprey (Pandion haliaetus), a diurnal raptor, migrating dwon to the Pantanal from the USA, where they nest. 
Ospreys are found on every continent but Antarctica, but in most places they are threatened by habitat loss and aquatic polution. 
They are always found close to bigger water bodies fishing from the air, dropping out of the sky they can dive more than a meter into the water to catch the fish. 
Ospreys are the only raptors together with owls where the outer toe is reversible, allowing them to grasp their prey with two toes in front and two behind. 
In my oppinion, on of the most elegant birds we find here !