Scientists often refer to the use of tools as an indicator of intelligence within a species. Tools are defined as objects, other than a part of a bird's body, that are used for a useful purpose. Tool usage is an indicator of a species ability for inventive problem solving, flexibility of mind and their ability to learn and adapt.
There have been many reports of tool usage by various species of birds. Darwin observed a finch in the Galapagos that fashioned a tool out of a twig to retrieve insects or larvae embedded inside branches. Crows in Japan commonly either place nuts under the tires of parked cars and return once the nuts are cracked or they position themselves on wires over a busy intersection and drop the nuts so that passing cars will crack them open.
There have been instances of tool usage reported in parrots as well. For example:
- Amazons, African Greys and Cockatoos have been noted to use objects to scratch the backs of their heads. (Check out the video of a parrot demonstrating tool use).
- Hyacinth Macaws have been reported to use pieces of wood inside their lower mandible to position palm nuts in such a manner that they are easier to crack (Hohenstein, 1987).
- Black Palm Cockatoos have been observed using a leaf inside their lower mandible to prevent the very hard kanara nuts from slipping when they try to crack them (The Malay Peninsula, Wallace, 1872).
- Black Palm Cockatoos are also well known for their "drumming" behavior whereby they use a stick to beat on a hollow limb or log (Wood, 1984). It is thought that this is a courtship behavior and the drumming is often accompanied by the spreading of wings, a raised crest, whistling call notes and a slow turning dance.
- An Eclectus in a zoo was reported to have been observed using a part of a palm leaf to scratch out a hollow for her eggs in the ground (The Minds of Birds; Alexander Skutch, 1996).
- Parrots have also been reported to use cups to dip water for drinking (The Minds of Birds; Alexander Skutch, 1996).