Population density and social, territorial, and physiological measures in the gerbil (Meriones unguiculatus).

Conducted 2 experiments with 80 male and 80 female Mongolian gerbils reared from weaning to adulthood in 4 same-sex and 4 mixed-sex density conditions. Ventral gland marking was greatly affected by density and less so by sex in both same-sex and mixed-sex groups. In same-sex but not mixed-sex groups crowding depressed several social interaction measures as well as body, ventral gland, and testis weights. In the mixed-sex groups, paired males and females had heaviest adrenal glands, ventral glands, and marking scores, as well as the highest reproductive rate. Mixed-sex crowding did not depress either social or physiological measures as much as did same-sex crowding. Effects of crowding are discussed in the framework of an information overload concept. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)