Potoos are some of the most cryptic birds around. This video, which isn’t on YouTube, was made by Ciro Albano and shared by Novataxa (link provided by Florian M.).
Click on the screenshot below to see a short but stunning video of a Rufous Potoo (Nyctibius bracteatus) rocking on its perch, apparently mimicking a twig or leaf blowing in the wind. The bird is not being blown itself: it’s rocking to deceive predators. This is something completely new to me, but is described in Wikipedia:
The rufous potoo is the smallest member of its genus, and extremely well-camouflaged, being almost invisible among dead leaves, trees and otherplants. Its body is, like the common name implies, rufous with white spots on the underbody. To improve their camouflage even further, they will rock back and forth while roosting to even closer resemble a dead leaf. They sing almost exclusively on full moons.
. . . This species has a unique nesting habit. They make their nest upon a broken, vertical branch and produce one egg with unerring aim into their nest. Their dead-leaf like movements make this effective camouflage for predators that would prey upon their offspring.
Now you tell me that evolution isn’t amazing, for I strongly suspect that this behavior isn’t learned, but an evolved, hard-wired trait, expressed only when the bird feels the wind.
That bird looks pretty cryptic without the movement. Wouldn’t it be better (and evolutionarily easier) to just stay still rather than moving? I know the answer is “No” because the thing moves. It just seems strange.
The bird does move its head a lot, so maybe the body movement masks the head movement.
Uh, evolution as tautology.
I think that looking like a leaf could deter predators. (It works for me!)
If a lot of small brown things are moving in the wind, but one small brown thing is not, it’s the motionless one that stands out to observers. Camouflage is about not breaking the pattern of your surroundings.
Never seen anything like it. Come back on a full moon.
Very cool!
Interesting, though I am not surprised.
Tangentially, when my kids were young I would hold them for hours moving my torus and head up and down at about a one Hertz and this would sooth them. I did this for years afterward even when I did not hold my kids…I had to unlearn that.
Now if I could just stop shaking my foot all day.
Your torus??
Conjunct with Jupiter in the seventh house rising, from the sound of it…. Or maybe just an auto-correct for torso. (Maybe some day someone will develop an auto-auto-correct!)
Awed by this behavior. A bit disappointed by the absence of a “Find the Potoo” headline.
That comes later (or earlier?) I’ve only seen potoos twice, and both times they were pointed out to me by experienced ornithologists.
That is highly naturalized leaf movement behavior. One feels that to understand how a leaf moves in the wind, one needs only consult a Potoo.
I see it does a lot of looking around. I wonder if the movements are in part to mask its doing that.
You’re the second to point that out. Makes sense to me.
Rather than feeling the wind, I thought perhaps it was watching the leaves on the nearby trees, to decide when it should be rocking and when it should stop.
That’s what it looked like to me.
This is reminiscent of mantises which rock forward and back when hunting, but the mantis is trying to hide from pray.
I think they are also trying to be overlooked by birds.
I like how the rocking slows as the branches in the background slow down.
I dunno. I find the common potoo’s camouflage even more impressive, and it’s both larger and stands completely still.
Video: https://www.youtube.com/watch?v=ZtjFG16ADZQ
By the way, there seems to be a mammal bias in autocorrect, as it keeps trying to change “potoo” to “potto”.
Amazing creature! I am now wondering when and how the rocking species and the frozen species diverged. Maybe the rocker was a population in a windy area which adapted due to a strange and wonderful mutation for unstable feet.
Actually, there are 7 species of potoos. I don’t know how many of them rock (well, I think they all rock!), but I know to be cautious about simple adaptive explanations.
Better to give a simple adaptive interpretation that may be wrong than pretending that a guess (hypothesis), knowledgeable or not, is worthless speculation. What if H. W. Bates, himself a mere naturalist, had held back on mimicry?
No need for caution! Despite what Gould taught, to err is not a sin. How else are we to learn?
Difficult to test, since the divergences within this genus are really ancient, and we probably can’t reconstruct the locations in which ancestors lived, much less how windy they were. You might be able to try something with extant species. If the species that act leafy live in windier areas than the ones that don’t, that would at least be a weak test of the hypothesis. I don’t even know the distribution of this behavior among species. Is N. bracteatus unique?
Well, thanks for the analysis. I very happy to know what the constraints might be on hypothesis creation even if not the definitive particulars. Fascinating to speculate, even if we will never know.
Thanksh for the video link, that’s quite impressive camouflage.
I couldn’t get the link in the OP to play for me, it just takes me to a “sign up for FaceBorg” page.
Wow. Those eyes are even more amazing to me than the crypsis. They look fake, like muppet eyes.
I’d like to know what the predators are – snakes or other birds?
If it’s other birds I wonder why many birds are colorful and obvious. Why aren’t there similar bird predators everywhere.
Do tree snakes hunt by sight? I would think not. No snakes have good vision, do they?
There are a few other birds that do this. I’ve filmed Thrushlike Antpittas doing this while standing still on the floor of a tropical rain forest.
Ah but who is to say that leaves blowing in the wind are not mimicking the mighty Potoo? Magnificent bird.
How many leaves must a potoo bird mimic
before she sleeps in the sand?
The answer my friend is not blowing in the wind.
(with apologies to Robert Zimmermann)
😜