Maternal retrieval of 87 young representing 42 litters of the African bush Karoo rat Otomys unisulcatus F. Cuvier, 1829 was studied in the laboratory. All 17 females studied retrieved young by nipple-clinging, but ten females also mouth-carried the young in 45 out of 93 trials. Unlike nipple-clinging, mouth-carrying was poorly developed, as young were carried by various parts of the body in a non-stereotyped manner. Mouth-carrying in otomyine rodents is unusual; all other species previously studied use nipple-clinging exclusively. Mouth-carrying in O. unisulcatus can be interpreted in two ways: (1) Nipple-clinging probably evolved in the ancestral otomyines where it reduced the risk of predation on young in unprotected nests. O. unisulcatus occupies well-protected stick lodges where young are not very vulnerable to predation. Hence, the selective advantage of nipple-clinging in O. unisulcatus may be less than in the ancestral otomyines, and it is possible that mouth-carrying may replace nipple- clinging. (2) Alternatively, mouth-carrying may represent merely an experimentally induced response.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.