The way that animal parents care for their offspring varies widely depending on the creature in question. For example, pregnant leather-back turtles crawl up on the beach at high tide, scoop out a hole, lay eggs, and trundle back into the ocean without even a backward glance. Their young hatch, never seeing their parents, and have to fend for themselves from day one. As you might guess, many get gobbled down by hungry predators before reaching the water. Crocodiles at least tend their nest and then watch over their young that hatch by protecting them in their mouth, a place of safely for the young, exceedingly dangerous for any other being. Warm-blooded mammals and birds as a group generally give much more care and attention to their brood. In fact, the word “mammals” derives from the milk-producing mammary glands that mothers have for feeding the little ones the perfect infant formula.
Some recent studies of rat mothers show that pups who received the greatest attention (licking and grooming) had the greatest brain development in terms of new synapses made in the hippo-campus, the area of the brain responsible for spatial learning and memory – an effect detected as early as the first birth. The benefit, of course, was that the pups were better at spatial learning and memory. The effect appeared to be because of more synapses per brain cell and greater brain cell longevity. The researcher ruled out enhanced brain cell proliferation as the reason for the spatial and learning improvements. In contrast, pups that had little maternal interaction actually had lower levels of the types of chemicals that promote brain development and experienced significant loss of brain cells in the hippocampus through programmed cell death, probably because they had lower levels of the types of chemicals that spur brain cell proliferation.
It seems every mother/offspring study shows the benefits of maternal care.