The Sketch

The American Coot: A Tough-Love Parent

A couple years ago, just after my daughter was born, my friend gave me a book called Parenting for Primates
Written by a primatologist-turned-clinical psychologist, it was full of advice gleaned from years of research on both human and non-human parents. I didn't actually read it—I avoid parenting books like the plague—but I liked the idea that we human animals might have something to learn from animal animals about how to care for our offspring.

That said, I’ll tell you one animal I'd never take parenting advice from: the American Coot.

Fulica americana, a member of the rail family, is sometimes known as the mud hen, owing to its love for marshes, ditches, and the occasional sewage-treatment pond. Adults have all-black plumage, a mostly white bill, green legs, and a dull-red forehead shield called a callus. Coots have a reputation for being rather stupid and churlish, which is where the epithet “You old coot!” comes from, and I've heard that they “discipline” their chicks by grabbing them by the head and thrashing them around. That adult coots have red eyes doesn’t help things, and neither does their call, which John James Audubon described as “a rough guttural note, somewhat resembling cruck, cruck, which they use when alarmed, or when chasing each other on the water in anger.” 

So, yes, churlish. But stupid? One thing you can say for coots is that they are brainy enough to navigate a family life that might have given Machiavelli pause. The complexity of their domestic situation stems from two facts: The first is that while female coots lay a lot of eggs—eight to twelve per clutch—most coot parents won’t find enough food to satisfy all their chicks, so nearly half of them will starve to death. The second fact is that coots are conspecific brood parasites, meaning that if the opportunity presents itself, females will lay an egg or two in another coot’s nest. (In one study, 41 percent of nests were found to be parasitized.) In the cold calculus of evolution, raising non-related offspring is about the worst thing an animal can be tricked into. And when there aren’t even enough resources to go around for your own chicks, let alone genetically irrelevant frauds, what’s a coot to do?

Quite a lot, it turns out. First, coots can count, and since they’re indeterminate layers, they’ll keep laying eggs until some external cue tells them to stop. Usually, that cue is the number of eggs in the nest. So, in theory, if you’re basing your decision about whether to lay another egg on how many you already have in your nest, and some freeloading neighbor coot has managed to sneak a couple of her eggs into the mix, the result will be that you won’t lay as many of your own. That’s bad. But, fortunately for the coots, they can identify other parents’ eggs based on differences in color and pattern, and sometimes they’ll push those guys to the sides of the nest. Then they’ll lay a full complete set of their own eggs. That’s good. 

Also, that disciplining I had heard of? That also has to do with a chick’s relatedness. Just as coots can identify their own eggs, they can also identify their own chicks, by paying a little attention to their hatching order. Here’s how the coot logic works: “Since I’m probably going to lay the first egg in my own nest,” thinks the coot, “the first chick to hatch from that egg is going to be mine. Any other chick that looks like that first chick is probably mine, too. Any chick that doesn’t look like that first chick is probably not mine.” 

And thus are the imposter chicks identified. Then the would-be adoptive parents peck at them, and sometimes drown them.

That helps them avoid wasting precious resources on a chick that's not even carrying their DNA. But coot parents are still left with the reality that about half of their own chicks aren't going to make it, which means that they have to play favorites—albeit in kind of a fickle way. After the eggs are laid, they take between three and ten days to hatch, and the first chicks to pop out tend to be the largest of the brood. In the beginning, as is typical among birds, coots favor those bigger chicks, feeding them at the expense of the smaller ones. The big chicks get all the food and the small chicks die, and it’s all very sad, et cetera, et cetera. Except...sometimes they don’t die. And if the seemingly feeble runty chicks are in fact able to demonstrate their heartiness by surviving a round of starvation, their parents will suddenly go from ignoring them to treating them like royalty. It's another equation in evolutionary calculus, thinking two steps ahead to increase the odds of sending healthy coots out into the world.

So, if you're not into child-rearing books either, here's the Cliffs Notes version of Parenting for Coots:

Chapter 1: Never trust your neighbors—count those eggs.

Chapter 2: If you suspect one of your brood isn’t actually yours, don’t bother raising it. But do beat it up, and maybe even kill it.

Chapter 3: Favor the bigger chicks first. Not only are they more likely to be yours, they're also more likely to survive.

Chapter 4: If a scrawny chick does buck the odds and hold on, by all means, stuff it with food and pin your hopes and genes on it.

I personally wouldn’t buy this book, but maybe I’m being too critical. Sometimes my daughter and I walk to the big lake near my house and see hundreds of coots flocking there. “Coots! Coots!” she yells, pointing happily. So many coots. They must be doing something right.