Bird brains

Despite what we might think, birds do have personalities, and can be quite different  from one another even within the same species.  Take the case of two House Wrens who happen to be nesting quite close to one another in cute little wren boxes in this lovely garden (of a friend).

Diamond-shaped boxes  with just the right-sized holes attract House Wrens.

Diamond-shaped boxes with just the right-sized holes attract House Wrens.

My presence (along with that of a friendly cat) immediately set the wrens to chattering and scolding.  I could see that they were busy feeding their broods in the nest box, so I stood quietly and watched.

One wren was quite perturbed by my presence and flew from perch to perch, trying to decide whether it was safe to enter her nest box or not.  She had a juicy caterpillar to feed her chicks.

I assume this is a female because she still has a bare abdominal area where her brood patch was.  First she sat in a tree and scolded me.

I assume this is a female because she still has a bare abdominal area where her brood patch was.  First she sat in a tree and scolded me.

Then she sat on a tomato cage and scolded me, quite loudly considering that she kept her beak closed around that caterpillar.

Then she sat on a tomato cage and scolded me, quite loudly considering that she kept her beak closed around that caterpillar.

Then she moved to within about 6 feet of the nest box, but still hesitated to enter.  That caterpillar is starting to look dehydrated.

Then she moved to within about 6 feet of the nest box, but still hesitated to enter. That caterpillar is starting to look dehydrated.

Oops, what happened to the caterpillar -- did she drop it or eat it?  She is sitting right opposite the nest box and giving me a piece of her mind.

Oops, what happened to the caterpillar — did she drop it or eat it? She is sitting right opposite the nest box and giving me a piece of her mind.

Contrast this behavior with that of another wren (couldn’t tell if it was male or female) feeding its offspring in the box next door.

"I have something to feed my babies -- don't look while I approach."  This wren made two short hops in a bush next to the nest box and then popped inside.

I have something to feed my babies — don’t look while I approach.” This wren made two short hops in a bush next to the nest box and then popped inside with a big, juicy fly.

Task completed -- off to find another meal.

In and out, task completed — off to find another meal.

You can see how natural selection might act here, depending on the type of threat.  Wren A’s chicks might not get fed as well and perhaps not all of them would fledge but she doesn’t give away the location of the nest. Wren B’s chicks might get lots of food, but could be easily discovered by a predator, since the bird made no attempt to disguise where it was headed with its prey.  Good thing there is such variation in behavior among individuals, insuring that some will exhibit the appropriate response and survive.

14 thoughts on “Bird brains

  1. I’ve always wondered what exactly it is that animals see when they look at us and I’d love for science to figure out how we could get a glimpse of the world through their eyes. It’s a tall order I know-probably impossible- but I think it would be more fascinating than just about anything I’ve seen.

  2. Great! The wrens don’t mind people but all of a sudden they hate the cat, I wonder if the first brood is about to fledge? M

    Sent from my iPad

  3. Nice shots, Sue. You’ve posed some questions that could take a lifetime (or two) to answer about why birds respond as they do. How do they perceive threats? What causes them to respond differently in similar situations? You made some fascinating observations from your limited sampling of their behavior about the tradeoffs involved between security and feeding the families.

  4. I wonder if, and how, past experience might be affecting their current behavior. Perhaps Wren A had some near-death experience with a predator previously while feeding a brood, or with a human being too inquisitive. While Wren B could not have these experiences and is simply trusting because you aren’t waving your arms around like a ninny making unintelligible noises.

    We have chickens and I totally agree that birds have different personalities and IQs.

  5. Birds do have different personalities but you spotted those two’s personalities very quickly. I have nest box envy, I even love the blue colour they have been painted. I have always felt nest boxes should blend in with the background and be unobtrusive. Mind you I have never been very successful with nest boxes. 😦

    • I don’t think the birds care what color their nest boxes are, although that could certainly be tested. I can see it now, a row of nest boxes each painted a different hue of the rainbow, and we’ll track which are chosen!

  6. Pingback: Do bees have different characters? | a french garden

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