Hoarding behavior in the pigeon (Columbia livia): performance under the restriction of food availability.

The effect of restriction of food availability on food-earning behavior was investigated in two pigeons (Columbia livia) in a closed economy paradigm. Experimental chambers that allowed them to store food were devised. They were exposed to two kinds of feeding conditions. One condition was a free-feeding condition in which the bird could earn food at any time of the day by pecking a key. The other was a restricted-feeding condition where the food availability was restricted only for a given time of day. Consequently, one bird overtly hoarded food. After the bird was exposed to the restricted-feeding condition, this bird learned to obtain extra food and left some food uneaten for later consumption. Moreover, this bird utilized the hoarded food and compensated for the reduction of the income. Thus, after an experience with the restriction of food availability, the bird learned to obtain extra food that was not consumed immediately and left it uneaten.However, in the condition where essential food but not extra food could be earned, the bird did not hoard food.