Personal space in Patagonian cormorants: a huge and neatly-arrayed group of nests

March 10, 2015 • 2:30 pm

From Grind TV we have lovely video and photographs of 5300 pairs of Imperial Cormorants (Phalacrocorax atriceps, also known as “Imperial Shags”) nesting en masse in Patagonia.  The nests cover an area of 2000 m², which is less than half the area of an American football field.

From the site:

Dr. Flavio Quintana, who has studied cormorants for more than 10 years, shot video from a drone, which is proving to be a cheaper and safer method for studying the seabirds than using pilots and photographers, as in the past. Here’s the captivating video provided by Caters News Agency:

And some photos:

Incredible Nesting Birds

Quintana, as we said, is no stranger to these seabirds.

A few years ago, he discovered just how amazing the feeding techniques are of the imperial cormorant, which dives into the water to catch fish. His research showed that one “superbird” dove 150 feet underwater in 40 seconds, spent 80 seconds searching for a meal on the ocean floor—eventually catching a snakelike fish—then returned to the surface 40 seconds later.

Incredible Nesting Birds

Incredible Nesting Birds

Incredible Nesting Birds

The aerial photographs not only allow an accurate census, but also give behaviorists the ability to see how even the spacing really is, and whether it corresponds to how far the birds can stick out their necks. My own theory, which is mine, is that they’re spaced just far enough apart to prevent the birds from pecking each other. But I’m sure that some ornithologist has already got the answer.

h/t: Doris

43 thoughts on “Personal space in Patagonian cormorants: a huge and neatly-arrayed group of nests

  1. Stunning, what a landscape! I’d like to see how they make the nest mounds.
    The neck length theory makes me think of the two sword-lengths plus an inch distance between the government and the opposition sides in the House of Commons (UK, Canada etc.)

  2. This is a hexagonal close-packed arrangement, more of less. Maybe Deepak can use this to claim that free energy minimization scales all the way up to bird nesting.

    1. It’s geometry though, isn’t it? If you add marbles to a container and stop when the next marble will not rest on the bottom, you get hexagonal packing because circles.

      I think the real Deepakity (Deepackity?) here is that the overall arrangement forms the head of a pteradon, obviously a hierophany of the latent dino-bird spirit.

      Or, it could be a ballpeen hammer. Which is just a silly thing for birds to manifest.

      1. I’m now realizing that soft-condensed-matter jokes are dead on arrival. I was trying to imply that the birds are socially exhibiting thermodynamic phase behavior, which is actually true, in some sense. [I have just Deepak-ed myself] If two birds build their nests next to each other (assuming the colony, largely speaking, starts out that way) and then a third bird starts to build its nest roughly the same distance to those two, and so on and so forth, you’ll get an hcp arrangement of nests. This is basically what you’re suggesting. If you’ve ever watched 2D colloidal crystallization or bubbles rising and packing at the air/coke interface within a plastic coke bottle when it’s opened slightly, that’s how it proceeds. If several nucleation sites start and eventually merge, you get a polycrystalline arrangement, which is what you see in that aerial photo. The freakiest thing is that the birds are leaning in random directions, so it looks like the short-time trajectories of particles in a 2D colloidal crystal. This nesting behavior could be easily simulated. I wonder what parameters are tunable. I’m done now.

        1. Sorry. Though I don’t know my arrangements from my phases from my states, I know enough to get the Deepak crack! Because he does that, with the physics and the woo!

          It’s the physics/chemistry that’s over my head, not the humor.

          I appreciate the resulting explication, though! Great stuff.

    1. I was thinking the same. Also, perhaps it’s not just pecking at stake: in a mass emergency take-off situation, how close do the wing tips get to brushing one-another? Any closer and I suspect they’d snag each other getting away (which could have its own benefits: “I don’t have to outrun the lion, I just have to outrun you” but perhaps a benefit with too great a personal risk).

  3. I suppose safety in numbers is the thing.

    The comorants here are probably the double-crested, Phalacrocorax auritus. Very entertaining birds and great fishers.

  4. It think Jerry has the right of it with the just-beyond-pecking-distance as the ideal spacing. It so happens the interstial flat areas are just about one bird body wide – so that’s likely a natural rule of thumb (or rather, rule of bum I guess) for placing one’s mound in the presence of the last.

    The whole contrivance seems very penguin-y to me somehow, but maybe I’m reading too much into it with the tuxedos and deep diving for fish. The birds in the middle have a nice shelter from the wind and predators, unlike penguins, though, they can’t shuffle and take turns being on the perimeter.

    Haven’t had a chance to watch the video yet; these and other observations popping into my head may well be addressed.

    1. Just guessing here but I would agree with the pecking distance notion and take it a bit farther – perhaps it’s to keep the eggs and hatchlings out of reach of the other neighbouring adults too, until they’re old enough to wobble out of the nest. I wonder… could it also have anything to do with the amount of space (wing span) they need to take flight?

      I think the roughly hexagonal shape might have to something to do with why honey combs are built up from many hexagonal cells. In the case of the latter, it’s the most optimal arrangement, using the least amount of material to make a cell and adds strength to the structure. The bird colony becomes a unit which offers the chicks some protection from predation and perhaps weather.

  5. “Which is mine.” Does Professir Ceiling Cat author theorems a la Anne Elk, who famously discussed her theory of the brontosaurus on Monty Python’s Flying Circus.

  6. How do the nest mounds get built? If the bird needs to be able to walk all the way around it during construction, that could account for the spacing.

  7. WOW.

    That’s my dumb comment, but I can’t think of any words that come close to describing how awesome that is. Dr. Quintana is living the dream.

    1. Reminds me of the story of the biology teacher who announced to his class that during the summer holidays he and his new wife were travelling to the Hebrides to study the cormorant and shag. A cheeky pupil replied, “I hope you enjoy the former as much as the latter”.

  8. I don’t know but, birds seem to have a personal space thing. They use it keep themselves from getting in each others way in flight. They use it sitting on an electric line. They may use it their nest building endeavors…

  9. What are the nests made of? Are there fibers, or is that built up guano? It looks like there are roots or branches in a few. Very cool to see babies (lower left in last photo). That could be a noisy place! Large nesting colonies can start to sound like a human crowd at an arena.

  10. I wonder if there are some cormorants that lament the fact that you can’t enjoy the beach because it is so crowded these days!

  11. Also notice that the nesting area is distinctly elevated above the rest of the beach. I wonder if the cormorants have compacted the sand into a weather resistant cement over many years?

  12. I would love them to do a bit of out of breeding season bird archaeology, taking a cross section or a core, to try to see how many generations it has taken to build up that level. I imagine it will be hundreds of years, but not thousands as sea levels will have risen since the last glaciation.

  13. I have observed the same thing in royal terns, and there is at least one paper on the hexagonal packing in that species. The terns do not build nests so the idea that walking space around the next helps add to the structure cannot apply to terns. In the terns, pecking distance perfectly explains the distance—several times I watched pairs of birds on adjacent nests lean forward and just about touch beaks.

Leave a Reply