Luiz Claudio Marigo / Rufous hornero / Ovenbird at mud nest {Furnarius rufus} Mato Grosso, Brazil

Pete Oxford / Ovenbird building nest, Pantanal, Brazil

Gabriel Rojo / Rufous hornero (Furnarius rufus) with prey in beak, on top of mud nest. Pantanal, Mato Grosso, Brazil.

Gabriel Rojo / Rufous hornero (Furnarius rufus) on top of mud nest. Pantanal, Mato Grosso, Brazil.

Gabriel Rojo / Rufous hornero (furnarius rufus) bathing, Ibera Marshes, Corrientes Province, Argentina

Gabriel Rojo / Rufous hornero(Furnarius rufus) with mud in beak, Ibera Marshes, Corrientes Province, Argentina

Tony Heald / Rufous Hornero / Ovenbird (Furnarius rufus) perched on nest, Pantanal, Brazil

Tony Heald / Rufous Hornero / Ovenbird (Furnarius rufus) with prey, Pantanal, Brazil

Luiz Claudio Marigo / Rufous Hornero (Furnarius rufus) at Pixaim River, Pantanal of Mato Grosso, Mato Grosso State, Western Brazil.

Luiz Claudio Marigo / Brown-chested Martin (Progne tapera) nesting inside a abandoned nest of Rufous Hornero (Furnarius rufus) Pantanal, Mato Grosso State, Western Brazil.

Luiz Claudio Marigo / Brown-chested Martin (Progne tapera) nesting inside a abandoned nest of Rufous Hornero (Furnarius rufus) Pantanal, Mato Grosso State, Western Brazil.

Roy Mangersnes / Rufous Hornero (Furnarius rufus) walking, Buenos Aires, Argentina, South America. November.

Roy Mangersnes / Rufous hornero / Ovenbird (Furnarius rufus) in the Andean mountains near Valle Nevado, Santiago, Chile. October.

Juan Carlos Munoz / Ovenbird / Rufous honero {Furnarius rufus} singing perched on large mud nest, Pantanal NP, Mato grosso, Brazil

Juan Carlos Munoz / Ovenbird / Rufous honero {Furnarius rufus} singing perched on large mud nest, Pantanal NP, Mato grosso, Brazil

Kevin Schafer / Rufous Hornero (Furnarius rufus) beside mud nest, Iguacu Falls, Brazil

Luiz Claudio Marigo / Rufous hornero / Ovenbird at nest {Furnarius rufus} Mato Grosso, Brazil

Pete Oxford / Rufous hornero / Ovenbird building nest {Furnarius rufus} Cerrado, Piaui, Brazil.

Pete Oxford / Rufous hornero / Ovenbird building nest {Furnarius rufus} Cerrado, Piaui, Brazil

Konrad Wothe / Rufous Hornero (Furnarius rufus) at nest, Pantanal, Brazil

Hermann Brehm / Rufous hornero / Ovenbird at entrance to mud nest {Furnarius rufus} Pantanal, Brazil

Hermann Brehm / Rufous hornero / Ovenbird at mud nest {Furnarius rufus} Pantanal, Brazil

Hermann Brehm / Rufous hornero / Ovenbird pair on mud nest {Furnarius rufus} Pantanal, Brazil

Gabriel Rojo / Ovenbird / Rufous hornero pair at nest on telegraph pole {Furnarius rufus} Argentina

Gabriel Rojo / Ovenbird/ Rufous hornero {Furnarius rufus} Argentina

Hermann Brehm / Mud nests of Rufous hornero / Ovenbird {Furnarius rufus} Pantanal, Brazil

Hermann Brehm / Rufous hornero / Ovenbird at mud nest {Furnarius rufus} Pantanal, Brazil

Hermann Brehm / Rufous hornero (ovenbird) pair singing on nest {Furnarius rufus} Pantanal, Brazil

Pete Oxford / Rufous hornero / Ovenbird {Furnarius rufus} building mud nest, Pantanal, Brazil

Pete Oxford / Ovenbird nest {Furnarius rufus} built of mud Pantanal, Brazil, South America

Agustin Esmoris / Rufous Hornero (Furnarius rufus) in nest cavity, Chubut, Argentina

Peter Waechtershaeuser/ BIA / Rufous Hornero (Furnarius rufus) at nest, Pantanal, Brazil

Agustin Esmoris / Rufous Hornero (Furnarius rufus), Pedro Luro, Argentina

Bruce Thomson / Rufous Hornero (Furnarius rufus) standing on ground, Pocone, Brazil.

Bruce Thomson / Rufous hornero (Furnarius rufus) perching on a wooden stump, Pocone, Brazil.

Bruce Thomson / Rufous Hornero (Furnarius rufus) peering out of old mud nest, Pocone, Brazil.

Sylvain Cordier / Rufous hornero (Furnarius rufus), two males fighting for the territory, Pantanal, Mato Grosso, Brazil.

Sylvain Cordier / Rufous hornero (Furnarius rufus), two males fighting for the territory, Pantanal, Mato Grosso, Brazil.