[kreelman]

Interesting title. These thoughts are before reading the article, use grains of salt as required.

I believe that birds brains are kind of uniquely advanced too. Lightweight (in terms of mass) structured differently to mammalian brains... I've heard a definition of sight as "a bit of the brain popping out for a look". I wonder if the same brain density tricks bird brains use are used in some parts of their vision system. This is all as my memory serves. Feel free to correct any mistakes in my understanding.

There's some very interesting work happening to understand their calls too. If (my) memory serves, there able to identify particular call types quite well now.

If someone calls you a "bird brain", perhaps that could be taken as a complement! Trying to do more with less!

Fascinating to also think that birds are of course evolved dinosaurs. Raptors of the sky. It would be fascinating to link whats being looked at here with any kind of data that can be pulled from fossil evidence (though there might not be much...). I wonder which unique bird genetic traits were useful or super enhanced dinosaur traits.

...I think the strong but light bone structure was something inherited from the dinosaurs too? Fascinating creatures.

On the face of it, seems sensible that avian evolution has spent many genetic GPU cycles to generate advanced vision needed to fly and hunt from the air.... One wonders which "subroutines" have been reused from dino-days, as mentioned.

[nkoren]

I had an an interesting experience with a bird brain today.

There's a robin who often sits in the fig tree in my back yard, giving friendly little chirps whenever I'm near. (I have no way of knowing whether it's the same robin from day to day, but if it's different robins then they all seem to be on the same wavelength.)

Anyhow, today a neighborhood cat came to the back door, and was aggressively friendly when I opened it. Clearly offering affection in exchange for... what? I've never given this cat anything before, apart from a friendly pat. Meanwhile the robin was overhead in the fig tree, giving totally different chirps than I'm used to. Clearly "warning!" "danger!" chirps. It was amazing how unambiguous they were.

I was puzzled who the robin's audience for this was, however. I'd never noticed it freaking out about cats before. Was it trying to warn me for some reason? Trying to warn other nearby birds? I couldn't see any. I thought that maybe it was just shouting at the cat out of general pique.

Then the cat led me to the answer. Turns out it had trapped an (uninjured) baby squirrel behind a planter box near my door. It couldn't reach the squirrel, and the squirrel couldn't escape. The cat seemed to be under the impression that since we were now friends, I could move the planter box and help it to get the baby squirrel. Sadly I had to disappoint it, and after unexpectedly acrobatic shenanigans, I facilitated the squirrel's escape instead.

The robin, meanwhile, ceased its warning chirps the moment it saw that I was aware of the baby squirrel. Then it watched the ensuing affair unfold, from the safety of the fig tree. Once the squirrel was safe and the cat had left disappointed, the robin looked at me, gave a few of its usual happy chirps, and flew away.

[m463]

crows warn about stuff.

If I go outside and the crows are going crazy, something interesting is happening.

Mostly it is hawks, and the crows will chase and dive bomb them.

Once I came outside and the crows were going nuts, but not flying. And right in the middle of the driveway was a bobcat. no wonder.

[KineticLensman]

> If someone calls you a "bird brain", perhaps that could be taken as a complement! Trying to do more with less!

(source - worked at a raptor conservancy). It depends on which bird. Some are really smart and can learn tricks (e.g. retrieving specific objects) for food rewards. They can work out simple puzzles, such as finding food hidden under sliding blocks. Crested Caracaras are examples in my experience.

Others are much less intelligent, in particular owls, who aren't particularly wise. They have great instinctive behaviours but can't solve puzzles. This is partly because, for their vision, a lot of their skull is filled with eye rather than brain - owl eyes are tubular rather than eyeballs and can't move in their sockets, hence the 270 degree neck turning.

[retrac]

when pigeons are navigating their brainwaves oscillate around 150 - 200 Hz

a 60 fps computer display for pigeon vision is like a sequential slideshow it's much too slow to blur into what they would perceive as motion

many species of birds when they switch posture the motion is so fast it is imperceptible to the human eye it's like switching from one still frame to another

humans have perhaps 1/10th the temporal granularity that pigeons have

this leads me to the conclusion that if birds have a subjective experience it has a very different tempo than for humans or indeed most mammals

[dredmorbius]

Birdsong also occurs at a far greater rate / tempo than human ears are used to distinguishing. To fully appreciate most birdsong it must be slowed considerably. This is similar to many rodent calls (also rapid and high pitched), and contrasts with, say, whalesong, which must be sped up not only to raise it to a (human-) audible pitch, but for the patterns to be sensible to us.

Some human musicians and composers have played with similar themes, increasing or decreasing tempos by huge amounts. Examples of slow pieces include As Slow As Possible by John Cage, with a performance begun in 2001 due to end in 2640, and Longplayer by Jem Finer, which lasts 1,000 years. Musician and YouTube Adam Neely has an episode addressing the fastest tempos discernable by humans. At the upper range, the inter-beat range simply merges into a new soundform, at about 15--20 Hz, the lower bound of human audio perception.

[soupspaces]

> different tempo

Cats also seem to have faster reactions that might be overlooked by our perceptive frame rate (imo, tested after recording interactions and reinterpreting them). Beyond eyesight, I suspect human breathing can be too noisy for their ears (consistent hissing).

[dhosek]

The thing I find fascinating about birds is that they’ve independently evolved warm-bloodedness in a completely different lineage from mammalian warm-bloodedness.

[adrian_b]

This is not completely certain.

There are similarities between the warm-bloodedness of mammals and birds that might not be coincidences.

An alternative possibility is that some ancestor of all extant amniotes already had some kind of warm-bloodedness.

Later, in the ancestors of crocodiles, turtles and lizards (including snakes), the capacity for generating heat has been abandoned, in order to save energy and allow them to survive with much less food than birds and mammals.

There is some evidence in favor of this hypothesis, besides the similarities in temperature regulation between birds and mammals.

For instance, in contrast with the amphibians, the lizards, snakes, crocodiles and turtles are dependent on high internal temperatures for their bodies to function correctly. Because they cannot generate internally the required heat, they must take it from the environment, so most of them can live only in warmer climates and they may need every day to do things like basking in solar light, before any sustained activity.

It is also known that already the ancestors of pterosaurs and dinosaurs had their bodies covered by some kind of hair, which might have had the purpose of thermal insulation. Later, that hair has evolved into the feathers of birds and of those dinosaurs more closely related to them, while in the biggest dinosaurs the hair or the feathers were lost, like also in elephants and other such big animals where cooling becomes the problem, not heating.

At least for some dinosaur or pterosaur fossils bone growth patterns are consistent with high body temperature. In the line of synapsid amniotes leading to mammals, high body temperature also appeared earlier than any ancestor of the extant mammals, but it is not known when exactly this happened.

In conclusion, perhaps warm-bloodedness (homeothermy) has appeared independently in the ancestors of birds and of mammals, but perhaps not, it could have also appeared before the split of amniotes into these 2 branches.

In general, this is the most difficult in guessing the past evolution, when you have a feature that exists only in some of the descendants of a common ancestor, is this because of independent gains of that feature, or because all the groups that do not have the feature have lost it.

Most mistakes made in the past about the evolution of living beings have been caused by underestimating the probability of multiple losses, because it was wrongly believed that evolution goes from simple to complex. Now we know that losses and simplifications are extremely frequent, typically more frequent than the development of complex features, which happens independently more seldom than assumed in the past.

[dhosek]

This is maybe even more fascinating than warm-bloodedness evolving twice.

[bashkiddie]

Thank you for this long context!

[vkou]

There are a lot of metabolic advantages to warmbloodedness, it makes some sense that it could evolve independently multiple times.