2015 Pan Pacific Veterinary Conference

Postnatal maturation of sensory, motor and perceptual capacities support and constrain behavioural interactions between mammalian young and the mother, any littermates and the environment. Three groups of young distinguished by their neurological immaturity/maturity at birth are considered. Mothers in these groups exhibit distinctive patterns of birthing and postnatal care behaviours that compensate for behavioural inadequacies imposed by the limited sensory capacities the young possess at each stage. The levels of neurological immaturity/maturity are reflected in how long it takes after birth for the necessary brain circuit connectivity to develop sufficiently to support cortically based cognitive modulation of behaviour. This takes several months, days-to-weeks or minutes-to-hours in young that are, respectively, neurologically exceptionally immature, moderately immature, or mature at birth. Once achieved, cognitive awareness confers the high degree of behavioural flexibility required for young to respond successfully to the unpredictability of their postnatal environments. Such behavioural flexibility begins when exposure of mammalian young to levels of environmental variability first requires it.