Discrimination behavior mediates foraging quality versus quantity trade-offs: nut choice in wild rodents

Discrimination, the ability to distinguish sensory stimuli and respond accordingly, is a critical factor underscoring optimal foraging decisions. Nevertheless, little is known about how mammals discriminate between apparently similar foods of different quality. Here, we compared the foraging behavior of Chinese white-bellied rats, Niviventer confucianus, and Edwards’s long-tailed giant rats, Leopoldamys edwardsi, under natural conditions in the field and in a captive enclosure without predation/competition. We examined the behavioral processes involved in discriminating between sound (i.e., undamaged) and insect larvae-infested nuts of seguin chestnuts (Castanea seguinii) and demonstrated that both rats could discriminate nut quality, where nut examination improved the rats’ success rate at selecting sound nuts. Despite similar extents of discrimination-derived benefit in both settings for each species, differences between species-specific discrimination processes were identified. Chine...