Complexity of chemical communication in mammals: urinary components mediating sex discrimination by male guinea pigs

Male guinea pigs are more attracted to urine from female guinea pigs than to urine from males. Separation of urine into fractions characterized by molecular weight and functionality through several different methods established that this discrimination and preference is based on a pattern of components which have widely different chemical character. The active compounds range from macromolecules (MW >10,000) to small, relatively volatile molecules. These studies establish a complexity in chemical signals that has not been previously documented for any other species.