The Hornero, also known as an Ovenbird, is part of the Woodcreeper family. It is a rather soft, light-brown bird with a hue of red on its wings.
Horneros build nests that resemble old-time ovens in South America. The entrance forms a curved doorway to protect the chicks from the intense winds and predetors. The nests contains 2 chambers for the 3-4 chicks.
An adult hornero can frequently be seen sitting on top of its nest. It uses its wings to force air out and create a loud cry when in distress.
What you see in the picture below is a nest, painstakingly constructed by a bird name "Hornero" (Furnarius rufus).
Before our ecological times, it was common practice by the linesmen to destroy the nest to avoid the problems mentioned above.
Another solution, adopted later, was to install between insulators a wire structure which prevented the "Hornero" from constructing the nest on the crossarms.