My baby looks like a Francois Langur!

You'll just have to take my word for it, because I lack photographic evidence, but Baby Field Notes looks just like a newborn Francois Langur.

She gets the same drowsy, relaxed look on her face. She's got the pointy little monkey ears, the plump upper lip hanging over a receding chin... the almond eyes, the fluffy red hair. A hint of a spike mohawk.

There's no way to get around the superficial resemblance of baby humans to baby monkeys, but one thing you may not know about is another way that human and monkey infants are alike — the presence of a natal coat. A natal coat is the term for the different coloration of primates during infancy that later changes. Only about 10-20% of primate species are born with different hair color than they'll have as adults.

These francois langurs are relatives of silver leaf monkeys. Like the silver leaf monkeys, they give birth to bright orange babies that stand out in stark contrast to the significantly darker adults. Black and white colobus monkeys also have babies with a conspicuous natal coat. Theirs are completely white. Chimps are born with tufts of white hair on their rears (I think it makes them look especially cute!), and some human babies and toddlers go through a blond phase before they become brunette as adults. The natal coats that chimps and humans show are less conspicuous but no less noteworthy.

Primatologists, admittedly, don't know why primates are sometimes born with a different hair color, but they have some decent hypotheses. One is that the different coloration provides a signal to others that the baby is indeed a baby and that elicits extra care from elders. Another is that the stark contrast helps adults see the babies better in a dark forest and this may help the troop better protect them from predators (who could also see them more easily, but this cost is presumed to be smaller than the benefit of adults being able to readily see the baby). Both hypotheses propose the coloration denotes the individual is young and needing extra attention. Perhaps in the same way that little blond ringlets are cute on toddlers, orange fur on these primates makes them look especially cute to adults.

No one has studied the natal coat thing among humans, and it has really not been well studied among other primates, but I think it's an interesting subject for research. Some evolutionary psychologists think that the reason that blondes are so attractive in our society is that blond hair is a trait usually seen naturally only in the young and therefore blond hair on an adult woman signals youth and therefore, fertility.

Right now Baby Field Notes has golden red hair. In the sunlight it's the color of the baby francois langur pictured above. It will be interesting to see if she developes blond hair as toddler like Mr. Field Notes had. I never did.