"Tasting and wasting" behavior in non-human primates: aberrant behavior or normal behavior in "times of plenty"

The purpose of this study was to develop a foraging model that engenders large meals. Eight free-feeding baboons were first given periodic access to a chocolate sugar-coated candy (M & Ms) and then a jelly sugar-coated candy (Skittles). Baboons had access to food 24 h each day, but they had to complete a two-phase operant procedure in order to eat. Responding on one lever during a 30-min appetitive phase was required before animals could start a consumption phase, where responding on another lever led to food delivery, i.e., a meal. 3 days a week for 8 or 9 weeks baboons received candy during the first meal and then food pellets were available: a 2 month interval when only pellets were available separated periods of candy access. All baboons ate as much candy in the single candy meal as they did pellets throughout the remainder of the day. Beginning week 5 of M & M access, five baboons began to waste a large number of M & Ms by spitting them out. Baboons wasted few Skittles or pellets. Pellet intake was less, but total caloric intake was greater on days that animals had access to either candy. Pellet, but not candy eating varied between males and females: males began eating pellets sooner in the day, ate more pellet meals and more pellets. Periodic access to a preferred candy food engendered large amounts of candy consumption in all baboons, and periodic access to M & Ms engendered food tasting and wasting behavior in 5 of 8 baboons.