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I'm guessing the reason birds' brains are so much smaller for a given level of intelligence is that there is so much more evolutionary pressure to make things l

• lawlessone 1y ago
  Maybe it's like how we (most vertebrates) have blind spots built into our eyes due to a quirk of evolution, but some animal like squid etc don't... because their eyes have better cable management.
  • mystified5016 1y ago
    Kind of. There was no evolutionary advantage to removing the blind spot because brains adapted to compensate for it on a much shorter timescale than evolution. So most mammals still have the blind spot. Birds, on the other hand, have a disting evolutionary advantage in making their brains as small and light as possible. To me, this implies bird brains are likely to be much more efficient, both volumetrically and energetically. That's the more fascinating angle, IMO
    • lawlessone 1y ago
      Human brains have gotten a little smaller since we left the stoneage. Maybe the ours are getting more efficient too.
      • anthonypasq 1y ago
        in this podcast, its speculated that we have offloaded a lot of our intelligence to culture and the collective brain. Maximizing individual intelligence is less effective than maximizing social interaction and knowledge sharing for survival, especially for humans. https://www.youtube.com/watch?v=TcfhrThp1OU https://www.youtube.com/watch?v=TcfhrThp1OU
    • astrobe_ 1y ago
      Or perhaps the solution that evolution selected to solve other problems (microsaccades? [1]) also solved this blind spot problem. > Birds, on the other hand, have a disting evolutionary advantage in making their brains as small and light as possible. I'm not sure about that. Not all birds are as clever as crows. Who knows if a few less grams of neurons is worth the "IQ" loss, and conversely who knows if a few more grams of neurons makes a difference in terms of survival? Not to mention that these animals must also have vestigial or ridiculously expensive organs or functions (e.g. peacock's feather), so maybe they are not so sensitive to weight or energy consumption. It is difficult to measure. I've long been puzzled by the fact that if intelligence was such a big advantage - almost like cheating in our case - why is it not common? Well, for one thing we wouldn't have struggled a lot more to get to the top of the food chain. But Evolution is the process of adapting to an environment, and sometimes it selects what is "good enough". In a way flies are far more successful than us, because there are millions of flies for each one of us, and they are more likely to survive a planet-scale catastrophic event. Sometimes brute-force reproduction works better than more neurons. [1] https://en.wikipedia.org/wiki/Microsaccade https://en.wikipedia.org/wiki/Microsaccade
      • throwanem 1y ago
        Some wasps are about as clever as birds in some ways, especially with respect to socially adaptive forms of intelligence in social species, such as the ~1Kya selective sweep that resulted in members of the P. fuscatus species group developing the ability to distinguish individual conspecifics by their unique facial features. That's pretty impressive for about a hundred and fifty thousand neurons, and larger and more highly social vespid wasps (yellowjackets and hornets, vs. the 'paper wasps' of Polistinae), metabolically able to support larger brains, do better still. Their brains also aren't structured similarly to ours in a gross sense, although the so-called "mushroom bodies" do appear to serve similar purposes to our cortical "gray matter," and if I recall correctly, there is some sense that connectome complexity scales proportionately with complexity of behavior, though I'm not sure how well this has actually been studied. On a similar note, though their primary eyes aren't constructed at all like ours, they do nonetheless exhibit a "foveal" area of highest detail and resolution, in the regions of their eyes where it does them the most good - namely, ahead and below, the latter aiding in manipulation with palps, mandibles, and the front pair of legs. That's not quite the same as a brain per se, of course, but it does also point to the adaptive constraints under which evolution has occurred: as flyers who construct their own nests and who regularly must travel long distances to find all the resources a colony needs - or, as peripatetic mammals who came up grazing as much or more as hunting and use tools - good eyesight, memory, and dexterity are all very valuable, and thus it isn't a great surprise when such species that become successful on a cosmopolitan scale show extensive development of these traits. The infrastructure on which the trait is built may be independently of interest, but not being able to understand how such a small infrastructure gives rise to such global traits isn't an excuse for ignoring the exhibition of the traits. In light of all that - plus the anecdotes that such a close and friendly interest in wasps would tend to yield - I've tended to think of intelligence in this sense, or capacity for same, as sort of "holographic" in concept: if you make a hologram on film and then cut it in half, what you get is not two halves of a hologram, but two complete holograms, each with lower resolution than the parent. I think brains scale the same way, such that what you get with a much smaller brain is not so much less breadth as less depth. I don't really have a clear formulation of the concept, or not yet at least, but hopefully you can see at least a vague outline of what I'm reaching for. Or that I do, at least! Maybe we could think of it as the anthropic principle shorn of human chauvinism, if you like.
    • toasterlovin 1y ago
      At 20% of the body's total energy budget, I think the null hypothesis should probably be that there has been significant evolutionary pressure on human brain energetic efficiency.
      • mystified5016 1y ago
        I'm not so sure. Mammals have a huge energy budget mostly because we're endotherms. Humans are also pretty large as far as mammals go, and use more energy. The caloric enrichment of food by cooking probably can explain this as well. We got smart enough to cook, which gave us more energy from less food to power the brain. At that point, the evolutionary advantage of metabolic efficiency matters less. It allowed early humans to continue developing on the same path, probably increasing brain complexity somewhat over time while not focusing as much on energy. But I'm no biologist. I'm just guessing.
        • toasterlovin 1y ago
          Clearly the energetic cost of having large brains was worth it for humans from an evolutionary perspective, or else we wouldn't have them. But 20% of your energy budget is still a very large cost, so if there's a way to accomplish the same brain stuff for, say, half the cost, you would expect that to be very strongly selected for (caloric scarcity being the norm throughout human evolutionary history).
          • toasterlovin 1y ago
            I should say: this would be for pure efficiency optimizations absent any other tradeoffs. What I think you should see in birds based on their more extreme body mass constraints vs ground dwellers is different tradeoffs being worthwhile. Like, if there were an adaptation that required slightly more energy, but resulted in a brain that was much lighter; or doing various mental processes 20% less effectively for 50% less brain mass.
• ferguess_k 1y ago
  Talking about birds, I'm aware that certain species of parrots are considered to have comparative intelligence to a young child -- and they usually live a long life. I wonder whether it is possible to increase their intelligence further -- e.g. what if they are really as smart as 4-5 years old in one generation and a bit more in the next? Is there a way to "eugenics" (I know it's a bad word) birds on intelligence?
  • bpodgursky 1y ago
    Many will scoff, but many things that are possible that nobody has tried. Especially projects that take decades.
  • colechristensen 1y ago
    > Is there a way to "eugenics" (I know it's a bad word) birds on intelligence? Of course there is. Develop an intelligence test and remove the bottom x percentile from the breeding pool. Alternatively develop an environment that gives a competitive advantage to intelligence.
  • fn-mote 1y ago
    With animals this is normally called a "breeding program". For example, some dogs are bred for intelligence. Edit: Historically, there were "hunting birds" kept by the wealthy. Even today, but they are much more rare than dogs. Training and breeding would be standard practice in that environment.
  • bloopernova 1y ago
    One thought exercise I've had fun with in the past: We already control dogs' sub-species, so let's say we decide to uplift dogs to human level intelligence. How long would it take? At what point does it become unethical to modify a species that is on the way to intelligence? What does an evolved dog look like at different stages of their human-forced evolution? A modern dog is what (very rough) equivalent to which stage of human evolution?
    • cmrdporcupine 1y ago
• dboreham 1y ago
  ChatGPT vs DeepSeek.
• AngryData 1y ago
  I would also hypothesize that they need less brain because they need far less sensory input from their skin and body because of their feathers. They can't feel their feathers directly and their feathers protect their skin from abrasion and cuts so their is no point to really good sensory input from most of their skin other than to differentiate feathers for grooming and tell if their feathers are being touched or not. A bird for example is not going to force its way into brambles or thorns that poke their skin or push through brush in search of food like a mammal, they either avoid the thorns completely or have enough feather protecting them to ignore certain types of thorns. If they get into a fight they are relying almost entirely on feathers to protect them and any cuts or abrasions are often fatal.
• RachelF 1y ago
  Bird neurons are typically around 40% of the length, or 1/9 the volume of mammalian neurons. This means they have around 9x the number of neurons per unit volume. A large parrot has around the same number of neurons as a beagle dog. Combined with weight savings, this may allow their brains to work faster, which is useful for a flight computer. Birds have other features which are superior to mammals. For example, their flow-through lungs allow for more efficient gas exchange. However, having to fly means weight reduction has been a big driver of evolutionary compromises. A bird that can fly cannot carry large fat reserves around. They are not resilient when sick and often die quickly after the onset of visible symptoms.
  • yencabulator 1y ago
    Your comment made me think of cheetahs. An article once claimed that the biggest reason for cheetahs to perish in the wild was that at the speed they're running, even a minor mistake means they'll take a tendon-tearing or bone-breaking tumble, and their speed-optimized bodies are relatively fragile. Once they're injured, they are no longer fast, and thus lose their one and only predatory advantage. Humans really are surprisingly strongly generalist, in ways many other animals are not.
    • lukas099 1y ago
      Cheetahs are sports cars.
    • RachelF 1y ago
      Speaking of Cheetahs, pigeon fanciers like to compare their birds to Cheetahs. A 200gram grain-fueled homing pigeon can maintain 60km/h for an hour. A cheetah can do that for maybe a minute. I've always thought this is not really a fair comparison, as flying through the air probably requires way less energy than sprinting.
  • ASalazarMX 1y ago
    I hope someone else also wonders how smart a human with bird-like neurons would be. I feel weird even thinking about it.