The olfactory system of the tammar wallaby is developed at birth and directs the neonate to its mother's pouch odours

Abstract

In kangaroos and wallabies at birth the highly altricial newborn young climbs unassisted from the urogenital opening to the teat. Negative geotropism is important for the initial climb to the pouch opening, but nothing is known of the signals that then direct the neonate downwards to the teat. Here we show that the newborn tammar wallaby (Macropus eugenii) has the olfactory apparatus to detect smell. Both the main olfactory system and vomeronasal organ (VNO) are developed at the time of birth. Receptor cells of the main olfactory epithelium immunopositive for G oα-protein project to the three layered main olfactory bulb (MOB). The receptor epithelium of the VNO contains G-protein immunoposit..