The Romantic Tragedy of the Brood Parasite


I’m about to do a lot of talking out my ass on subjects I’m not certified to comment on, but what I’m about to say feels true to me, so … good enough for now.  Just don’t cite me in your term paper.

Today I saw a juvenile brown-headed cowbird being fed by a dark-eyed junco, the first time I have ever witnessed an act of brood parasitism.  I crossed the street to get a better look.  The most famous brood parasite is the cuckoo, whose creepy behavior has been folded into a number of human languages to represent male sexual paranoia derived from the attitude that women and children are more important as property than as people.  This includes the word “cuck,” beloved of internet racists and misogynists, though their memetic use of the word has outstripped any sense of meaning.

I’m not here to talk about that.  I’m talking about birds that destroy the eggs of other birds, leaving their own offspring to be raised by parents of a different species.  Birds that engage in brood parasitism are typically larger than the species they use, meaning that raising the changeling bird is more demanding and potentially dangerous than raising a member of the bird’s own species.  The brown-headed cowbird I saw was larger than its deceitfully adopted parent, a junco that seemed small and skinny as it went about its work.

How is a bird fooled into raising a child that doesn’t even look right?  Depriving itself to feed a monster twice its mass?  It’s like a sheep raising a calf.  A lot of birds just aren’t very smart, have to rely on pure instinct to drive them, and other birds can exploit that.  Even the brood parasites themselves aren’t necessarily clever.  They just happened into that niche a million years ago and it worked, to the point brown-headed cowbirds wouldn’t know how to raise a baby if they were in a position to do so.

Instinct is a weird beast.  People like to say humans have instincts that drive us and take the concept too far.  Yes, we have instincts, but they aren’t necessarily the ones people talk about, certainly the average evopsych tool.  The main instinct I see in people around me is social sorting.  We try to understand and control our relationships with the people around us reductively, drawing in and out groups, choosing arbitrary or socially promulgated ways of discriminating against others.  It can be turned back on ourselves.  When abused as small children or changed by life circumstance to a kind of person we have previously learned to hate, we sometimes socially sort ourselves as “unlovable” and hide away.

Instincts for non-human animals are much more obvious, and without as much ability to teach each other how to act socially, their instincts often have to be wildly specific.  Take cats’ burial of feces.  You do not have to train a cat to use a litter box.  Some cats may have dysfunction that needs to be sorted out, but most kittens will quickly figure out how to use a litter box.  Why?

Here is the instinct, in the cat’s mind:  “I have to relieve myself.  Ugh.  It feels right to do this on a surface that gives beneath my paws.  Ah, this dirt is just right.  Now I can go.  Holy crap!  This smell is terrible!  For some reason, I feel a tinge of mortal fear.  I want to wave my paw next to it.  Oh, that’s moving dirt.  Will scratching the dirt make the smell go away?  If yes, sigh of relief, carry on.  If no, RUN AWAY!”  Some people don’t know about the last part.  It’s hilarious to watch your cats tear ass across the house to get away from their mess, when burying isn’t enough.

Humans have almost nothing like this weird chain of highly specific inborn feelings, because we gained the trait of culture.  We can teach each other to wash our food, to bury our feces, and so on.  Practically anything necessary can be taught instead of relying on instinct alone.  Unfortunately for birds, they aren’t as bright as us.  They have to rely on feelings.

The instinct, in the bird’s mind:  “I got laid.  Woo!  Now I’ve got some other weird feelings setting in.  Better make a nest.  Unggh!  Eggs.  Better sit on these.”  The brood parasite slips in here, knocking eggs out of the nest and laying its own.  The victim of this sheisty move returns to find its eggs different.  (Some birds actually recognize the switch through various means and knock the cuckoo eggs off, try to start over.)  Apparently a lot of birds, even if they recognize the change, don’t know what to do with that, and just carry on.  “Sit on weird eggs.  Baby hatch.  Feed that thing!”

This is the tragic romance.  The finagled parent is operating on the closest thing a bird has to love.  It is selflessly giving up its food, seeking more and more, doing its best to keep this baby alive and well.  A brood parasite baby is even more demanding than its natural child would have been, potentially making the parent wreck itself with hunger and exertion in the process.  But the parent is driven to harm itself like that, for the love of this strange monster.  It’s beautiful and sad, it’s no kind of way to be.  If your human relationships involve giving until you are broken, reevaluate them.  A tragic romance is something to behold, not something to live.

Well, that went around the world, and I have no snappy way to end it.  Have a song.

Comments

  1. says

    I’ve had a lot of experience with human instinct because I’m a person that can feel the part that matches up with the funny feeling mentioned in the post*. I see the feeling as the stored instinct triggered by something in perception that launches an emotion as a reaction. I say “launches an emotion” because my reading of the literature (and preferred positions of people studying emotion) indicates that the whole response to what is in perception is an emotion and not just the feelings of emotion. The whole emotion includes the feelings of emotion (that represent real or simulated body states), changes to perception, manner of thought, memory access, and actions.

    The trick to thinking about instinct in human terms is that there is a “monkey brain” layer over a impulsive “lizard brain” core that allows different responses to be attached to the instinct based urges. When we are very young we do tend to react to urge in ways more similar to other creatures like the poor birds faced with cuckoo eggs. But early environmental exploration/interaction, role-modeling by family/other role-models and eventually personal choices followed by practice let us feel the instinct driven urge and choose how we want to respond.

    In abstract anyway. The reality is a lot more messy as plenty of impulsive adults and tremendous disagreement over what to role-model for children and one another in society demonstrates. The specific details about the variables I mentioned above including classes of instinct also change as we age (maybe in a series in an order similar to Maslow’s Hierarchy of Needs).

    *The first is an example of feeling urges in our motor system and the second is an example of feeling social related urges. We also feel urges related to perceptual choices, rumination, and other areas. Over the decades it actually gives a lot of information about how human urge and instinct is shaped in general which probably explains my fascination with how and why people do what they do and what urges inform those. I can recognize many of these urges in other people as they act and react.

  2. Great American Satan says

    Siobhan – Really no idea how old you are, but now maybe I have a hint. I remember like ten years ago, I’d just been graduated a short time, and was visiting a friend at the college. One of my old profs saw me and asked me if I was teaching there. It made me sad af because as bad as the school is I’d be so much better off if I was.

    Brony – Most of that stuff is way outta my pay grade, as they say. I’m glad people are approaching these issues in a more rigorously scientific way than evopsychers, and with more attention to the more abstract aspects of experience. Evopsychers love focusing on the kinda pop sci shit that makes headlines – gender differences in color choices, sexual preferences etc – but even banal stuff like checking your baggage at the airport or walking between rooms in a familiar building involve complex neurological activity with a half dozen potential ways to go wrong. I really feel like the better quality work being done in sociology, psychology, neurology, and so on are the best hope for sorting out why we as a species cannot get off the bullet train to greed-based extinction, seeing if we can do something about it.

  3. Ichthyic says

    They just happened into that niche a million years ago and it worked, to the point brown-headed cowbirds wouldn’t know how to raise a baby if they were in a position to do so.

    Not sure how this fits in, but not all brood parasites are obligate (meaning… it’s the only way they ever can breed).

    even within the family of cuckoos, there are species that actually can breed just fine on their own, or will switch to parasitism if the conditions are right.

    that said, since you seem to be interested in the ultimate question of the why of it, here’s a fairly recent paper on the subject of how obligate parasitism might have evolved:

    http://beheco.oxfordjournals.org/content/12/2/128.full

  4. Great American Satan says

    I just got the obligate thing on brown-headed cowbirds from wikipedia. That would be cool but a bit cruel to see if you could tease out the old instincts in them, trick lab birds into raising babies. Thanks for the additional info. 🙂

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