yes
The nest was built by birds.
Same way birds and other reptiles do: they push them out into a nest, then protect/incubate them until they hatch.
Usually a cock's nest
An 'eyrie' is the name for such a nest.
A crude nest built out of sticks, more like a platform.
No defenitely female birds will built the nest
A squirrel's home is called a drey. It is a nest made of twigs, leaves, and other materials built in the branches of trees.
The nest of a bird, such as an eagle built on a cliff is called an aerie Aerie or eyrie is the answer to the crossword puzzle.
Nothing but leave it alone.
If the bird built it then it is generally called a nest. If it was made for the bird by a human it is generally called a birdhouse.
other anacondas and people
No. Anacondas are not native to Australia.