No doubt this coscoroba is sitting on eggs. It was spotted by Diego Bastías on 7th July

No doubt this coscoroba is sitting on eggs. It was spotted by Diego Bastías on 7th July

Five species: Along with the coscoroba swan, ringed teal Callonetta leucophrys, Brazilian teal Amazonetta brasiliensis, Sirirí pampa Dendrocygna viduata and red-fronted coot Fulica rufifrons

With white-faced whistling-duck and cattle tyrant.

The Coscoroba Swan belongs in the family anatidae. A characteristic of this family is their webbed feet. Of the four feet three of them face forward and are joined by an interdigital membrane. The fourth toe, called hallux, is free and turns backward. In the photo we can see how the membrane folds when the foot is in a stand by position and how it expands when it stands. This membrane is useful to swim. Since it has a bigger surface the swan moves faster. When it makes a backward stroke toes are open and the web is expanded. When it moves forward toes are closed and the web folds to offer no resistance to water.

Body language of this pair of coscoroba swan before mating. They move in circles alternatively pecking at the water as an invitation. The female is much smaller than the male.