"Ouraka"
Magellanic Plover
Creative Commons Attribution Share AlikeMagellanic Plover - Credit: Alastair Rae

The bird identified as an ouraka is hard to attribute. It may be the threatened Southern Caracara, but that is mainly found further south in Tierra del Fuego and on the Falklands, and hardly fits Bill's description as the 'ugliest bird in the book.'

The tero-teros are almost certainly the Magellanic Plover which, in common with other plovers, makes a vicious screeching noise at those who stray too close to the nests they build on the ground.

Patagonian birdlife