In nature, many species of psittacines spend a good part of the day searching for food. In captivity, food is provided for the birds without them having to exert any effort to find it. Many parrots in captivity, such as Amazon parrots and Pionus, need to have the quantity of food they are given carefully monitored to prevent them becoming obese. In captivity, such birds live a far less active life than would be the case in nature. The way the food is prepared and presented to the birds can be important for some species.
Many cockatoos often prefer to be given larger pieces of fruits that they can pick up with a foot.
The palm cockatoo is the best example of this and rarely will pick up food directly with its beak unless the food item is too small for its foot to handle. The larger macaws all love to be given large pieces of primate biscuit, which they can grind in their bills. These food items are perhaps even more useful behaviorally than they are nutritionally. Smaller species, such as Bolborhynchus parakeets, love to have spray millet hung in the cage from which they can hang and pick off the seeds one by one. On a similar theme, we often provide our young macaws in their large free-flight aviary with branches of palm fruits suspended by rope from the roof of the aviary.