I started thinking about it during Ornithology class back in 2004.
We were talking about how some birds (e.g. songbirds) are born naked and blind and ugly and totally, fetally helpless. Others, like chicks and ducklings, hop out of the egg peeping and wander off to find a snack. Some mammals, like horses, are born ready to walk, while others, like puppies, are born blind and helpless.
Why the different strategies?

Precocial Chick
My Ornithology professor said that it all came down to predation risks vs brain growth. Animals born precocial (ready to get up and follow Mom to the food) have an obvious advantage against predators. In order for this to happen, the mother has to actually provide all the nourishment to the egg or fetus in order to get the baby to such an advanced stage of development before it is born.
Think of the elephant, with its pregnancy that lasts nearly two years. The benefit is that the baby can run and save itself shortly after birth, and the mother doesn’t have to fret much.
Altricial animals (can’t walk or even keep themselves warm) take less investment from the mother beforehand. The eggs are smaller, or the gestation time is short. Instead, the mother cares for them more on the other end. Perhaps because they aren’t hampered by growth restrictions, they end up with bigger brains and more complex behaviours in adulthood than precocial species.
…if they don’t get eaten first.
Then you have the greedy in-betweeners. Those animals make a big investment on BOTH ends. Very few species can afford to do this, but there is a pay-off if you can swing it: massive intelligence. Parrots do it this way… and parrots are effing brilliant.
Alex the Parrot, before he died, tested comparatively to a three year old child. I myself know a lady with an African Grey parrot and a Quaker Parakeet, and both of them use words meaningfully all the time. My own childhood pet parrot, who now lives with a wonderful lady in Ontario, used to scream “Where’s Carol?” in the mornings repeatedly until I appeared. He never used the phrase in front of me, but he’d harrass my parents when I wasn’t around, demanding Carol again and again. I don’t think he understood what he was saying, but he knew what context to use it in, and that using it would make me come running. Smart.
Thinking about this in class, I realized that we have semi-altricial young too. Like parrots, we make a huge prenatal investment – nine whole months in the womb, and usually only one at a time – but our infants are born early and take an even bigger parental investment on the post-partum end to keep them alive until they can fend for themselves. The benefit? Incredibly complex brains.
I’ve had a lot of people confess to me that they don’t find newborns cute – they find them ugly. That’s fair – in a way, our little altricial newborns still really are just external fetuses. Like baby robins, they are born before development is complete. For this reason, I am sometimes bemused by how much we differentiate a newborn from a fetus, culturally. A 39 week fetus and a baby born at 39 weeks are basically identical, developmentally.
Put me back in!
Study after study has demonstrated that human infants benefit from being kept close and carried as much as possible, because their bodies still need a womb-like environment for much longer than we are physically able to provide. We talk about the first three months after the birth being the “fourth trimester”. It will take another 6-9 months before a human infant has reached developmental age of… a newborn chimpanzee. Like those baby songbirds, still clearly fetal in their appearance, a human baby is altricial and desperately in need of intensive care.
We consider birth to be the big beginning. We talk about “when the baby comes” as if he weren’t already here. But he is. He’s in me, wiggling his butt around (and yes, the OB decided Monday that that IS his butt and he’s mooning me) and poking me in the pelvis. His behaviour is about the same now as it will be when he is born. He yawns and has hiccups and sucks his thumb and practices breathing. But I think it’s hard for us (including me) to really comprehend that. We can’t help but see birth as the big event, because that’s when we’ll see him.
Once he’s born, we’ll think of him as a separate being… but he really won’t be that, either. He’ll still be completely helpless, requiring my body for nourishment and warmth. Really, if it weren’t for humans’ massive brains he probably would spend the next three months or more inside me. But our brains ARE huge and our pelvises are narrow, so the baby needs to get out while he still can. It isn’t that he’ll be ready to be born. It’s that he’ll need to be, because my body won’t be able to carry him any further. Ready or not, he’ll get evicted.
So out he will come, still altricial… because my body ran out of room. To make up for it, I’ll have to provide a much less efficient support system from the outside. It is amazing to think how much he’ll disrupt our lives and change everything simply by moving over slightly in space a little. His needs won’t change, but our lives will go to pieces while we struggle desperately to create a womb-away-from-womb for him.
He should be inside, but he’ll be outside, and that will make the difference, the biggest of which that we can see him and must now consciously do what my body has been doing instinctively. When I think about it too much, my mind boggles a little bit. I know Babby is as real and present now as he will be in five or six weeks, and I’m doing a better job of caring for him now than I will be seven weeks from now. With the exception of some fat layers and better prepared lungs, he’ll be the same as he is right now…
…So why doesn’t he feel that real yet?