Competition for sucrose-pellets in triads of male Wistar rats: the individuals' performances are differing but stable.

After having individually been accustomed to consume palatable sucrose-pellets, the individual's competition-rate for sucrose-pellets within its familiar triad has been observed in male Wistar rats. In this fixed-triad, food competition paradigm high-performing rats (high competition-rate, majority of pellets consumed), medium-performing rats (medium competition-rate, consumption of some pellets) and poor-performing rats (almost completely abstaining from competition with only rare incidence of pellet consumption) can be distinguished. Intra-group rank-orders, defined according to the individuals' competition-rates (expressed as a score), were present in many triads and, once established, these were stable over months. No additional differences were observed between high- and poor-performing rats, neither when these were individually tested in an open field or in the elevated plus-maze, nor with regard to the preference for a sucrose solution.