the supervision by a female of essential nutrition for her young children until they're able of attaining their own food reserves. With regard to mammals, it consists mostly of the excretion of milk from the mammary glands and helping the offspring to locate the nipple in effort to suckle the milk, prolactin generates mammary gland growth, and oxytocin generates the milk letdown response. Some male birds, like the ringdove, supply a crop milk which is regurgitated to nourish young chicks.