Their head crest is the best way to gauge their emotions. If the feathers are standing straight up then they are excited or surprised. If the feathers are more relaxed, so is the bird. However, if the feathers on their head are laying flat against their head then the bird is angry!
Cockatiels (Nymphicus hollandicus) were discovered by Europeans in Australia in 1770, becoming popular in the 1900's during the Australian gold rush.
They enter their hollow nest tail first, their tail being so long that they cannot turn around in the nest.
The males have a bright yellow face with bold orange cheeks. The females have similar characteristics but their face plumage is duller.