Individual differences in choice of food items by pigeons.

Pigeons (Columba livia ) select food items idiosyncratically when feeding on grains (Brown, 1969; Moon & Zeigler, 1979; Giraldeau & Lefebvre, 1985). In three experiments pigeons under various conditions of food restriction were offered artificial "grains", pellets of pigeon food that differed only in size, to see whether individual differences in preference would still be observed. When 300-mg ("large") and 20-mg ("small") pellets were available simultaneously there were still wide individual differences in choice, but when encountering the same items successively pigeons took nearly all the items offered.