an autodidact meets a dilettante…

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Posts Tagged ‘birds

bird smarts and theory of mind

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human brain compared to that of a zebra finch, I think

I like birds a lot – how could you not? I particularly like their brains, which considering their ‘beautiful plumage’, their grace in flight, their songs, their treatment of mates and offspring and their dinosaur history, is quite a big call. Not that I’ve ever seen or examined a bird’s brain, but I’ve seen and heard of  some gobsmacking behaviour from some species, so I thought I might check out what’s known about their grey-white matter.

As with so many research fields, there’s been a surge in research into bird brains, and I’ve not heard the term bird-brain used as an insult in recent times. Still, when we think of bird intelligence, we tend to anthropomorphise, to compare them with us – do they play, do they use language or tools, do they recognise us individually, can they solve the same sorts of problems we can? That’s understandable enough, but in studying bird brains we should be just as thoughtful about the differences as the similarities.

The birds that have stood out for us so far are corvids – ravens, crows, jays and magpies, though many parrots such as the sadly endangered kea of New Zealand have also caught researchers’ attention. So how do these small-brained creatures manage to do the things that so impress us? Well for a start it may be more a matter of numbers than actual size (and it should be noted that birds have the largest brain to body ratio of any creature). Some research published in July 2016, which received a lot of media attention, found that bird brains pack neurons more densely than other animals. It was previously thought that neuron density didn’t vary much between species, but it’s now becoming clear this isn’t so, and actual brain size isn’t such a reliable guide to intelligence. But bird brains are really small compared to those of primates, so there must surely be other differences besides density.

But the 2016 research, which featured a revolutionary method for sampling brain tissue and making neuron counts, found that, in fact, a parrot brain contained as many neurons as some mid-sized primates. However, it’s also true that a bird’s brain is structurally different. Unsurprisingly, in the past, bird brains were thought of as primitive, and were classified as such, probably because they’re far removed from us on the evolutionary bush. Anthropomorphism again – understandably we used to feel that the only really intelligent creatures apart from us were those most closely related to us, but in recent decades we’ve learned that cetaceans, octopuses, elephants and birds, none of which are close to us  evolutionarily, are highly intelligent creatures. And they’re not all mammals, and in the case of the octopus, not even vertebrates. This is quite exciting for our understanding of intelligent life forms – they can have a multitude of ‘brain plans’.

The first important bird brain anatomist was the 19th century German naturalist Ludwig Edinger, whose work was so influential that it provided the orthodox view until a few decades ago. Noting the very different structure of the bird brain, Edinger understandably assumed they couldn’t be as smart as mammals, and being one of the first to name brain structures in birds, he assigned names such as paleostriatum, suggesting a very basic region involving instinctual and motor activity. Basically, he assumed birds lacked a neocortex altogether. However, we now know that the bird brain evolved from the pallium rather than the striatum, and in 2005 it was agreed that an overhaul of bird brain nomenclature was required. All part of our more informed and respectful approach to these wondrous creatures.

National Geographic, in combination with other interested organisations, has declared 2018 the Year of the Bird, and has some fascinating pieces on bird behaviour on its website. That’s where I learned that, according to one researcher, birds’ brains are more distributed ‘like a pizza’, whereas the mammalian brain is more layered. However, the wiring that underlies long-term memory in birds (and they clearly have impressive long-term memory) and decision-making is similar to that in mammals. 

Here are just a few of the extraordinary behaviours discovered. Green-rumped parrotlets of South America use calls as names for their chicks. Male palm cockatoos of New Guinea court females not only with calls but by drumming on hollow trees with twigs and seedpods – arguably a form of music. Goffin’s cockatoos, from Indonesia, make and use tools in captivity even though they’ve never been seen to do so in the wild. They’re also expert at opening locks. The National Geographic video ‘Beak and Brain: genius birds down under’ compares the kea of New Zealand’s South Island to the New Caledonian crow as problems solvers tasked with overcoming a variety of obstacles to obtain their favourite treats. It makes for riveting viewing. Other videos online show crows creating hooks on sticks and using them to pull food out of holes. 

Another video, involving experiments with jackdaws by Princess Auguste of Bavaria (really), a behavioural scientist, shows that these birds are much influenced by the gaze of humans, and can be directed to act simply by the gaze of a human they have bonded with. They also appear to know when they’re not being watched, and can act more boldly in such circumstances. All of this raises obvious questions, voiced by Auguste in the video. How do jackdaws think? How is it similar to the way we think? Do they recognise intentions? Do they have a theory of mind?

This theory of mind issue comes up with a lot of birds, and other animals. It refers to whether and to what extent a creature has the ability to attribute any or all of the variety of possible mental states to itself and/or others. The question of an avian theory of mind was explored in a study entitled ‘ravens attribute visual access to unseen competitors’. In describing their experiment, the authors highlight what they see – or what skeptics see – as a problem with much experimental work that tests for theory of mind in other species. This is the question – as I understand it – of whether the bird or animal actually ‘sees’ or reads what conspecifics are thinking, or is simply following particular observable cues. It was a complex experiment involving caching (hiding a store of food for later consumption, a common raven behaviour), peepholes that were either open or closed, and inference (by the researchers) from observed behaviour to either ‘minimal’ or ‘full-blown’ Theory of Mind. As a dilettante I found much of the discussion and analysis beyond me, but I found these remarks interesting:

In conclusion, the current experiment, together with the other recent studies on chimpanzees11,12, provides strong evidence against the skeptical hypothesis that the social cognition of nonhuman animals is limited to behaviour-reading. Peephole designs can allow researchers to overcome the confound of gaze cues, but further experimental work is needed to determine the specific limits of ravens and other animals—including humans—on such tasks.

In my general reading on these matters I’ve definitely found something like a rift between the skeptics on the behaviour of higher primates, dolphins and other ‘smart’ creatures, and those who have pushed, sometimes naively, other-life smarts with regard to ‘language’, memory and emotional intelligence. What I think needs to be kept clearly in mind is that in examining intelligence, or brain power or whatever, human intelligence may be only one of a possible infinity of gold standards. Is Theory of Mind itself an anthropomorphic concept, or one that lends itself too easily to anthropomorphic thinking? 

Meanwhile, experimentation and investigation of the neurological underpinnings of bird behaviour will continue, and I’ll be watching for the results. Just about to embark on Jim Robbins’ book The wonder of birds, and I hope to learn more especially about bird neurology in the future, and how it relates to birdsong. That’s a whole other issue.

Written by stewart henderson

November 2, 2018 at 9:40 am

this one’s for the birds

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Canto: If anybody doesn’t appreciate the beauty and complexity and general magnificence of birds they should pee off and never darken this blog again.

Jacinta: Right. Now what brought that on, mate?

Canto: Oh just a general statement of position vis-à-vis other species. Charles Darwin, an old friend of mine, was pretty disdainful of human specialness in his correspondence, but he kept a low profile – on this and everything else – in public. I want to be a bit more overt about these things. And one of the things that really amazes me about birds, apart from their physical beauty, is how much goes on in those teeny noggins of theirs.

Jacinta: Yes, but what really brought this on? I haven’t heard you rhapsodising about birds before.

Canto: You haven’t been inside my vast noggin mate. Actually I’ve been taking photos – or trying to – of the bird life around here; magpies, magpie-larks, crows, rainbow lorikeets, honeyeaters, galahs, corellas, sulphur-crested cockies, as well as the pelicans, black swans, cormorants, moorhens, coots and mallard ducks by the river, not to mention the ubiquitous Australian white ibis and the masked lapwing.

Jacinta: Well I didn’t know you cared. Of course I agree with you on the beauty of these beasties. Better than any tattoo I’ve seen. So you’re becoming a twitcher?

Canto: I wouldn’t go that far, but I’ve been nurturing my fledgling interest with a book on the sensory world of birds, called, appropriately, Bird sense, by a British biologist and bird specialist, Tim Birkhead. It’s divided into sections on the senses of birds – a very diverse set of creatures, it needs to be said. So we have vision, hearing, smell, taste, touch, and that wonderful magnetic sense that so much has been made of recently.

Jacinta: So we can’t generalise about birds, but I know at least some of them have great eyesight, as in ‘eyes like an eagle’.

Canto: Well, as it happens, our own Aussie wedge-tailed eagle has the most acute sense of vision of any creature so far recorded.

Jacinta: Well actually it isn’t ours, it just happens to inhabit the same land-form as us.

Canto: How pedantic, but how true. But Birkhead points out that there are horses for courses. Different birds have vision adapted for particular lifestyles. The wedge-tail’s eyes are perfectly adapted to the clear blue skies and bright light of our hinterland, but think of owl eyes. Notice how they both face forward? They’re mostly nocturnal and so they need good night vision. They’ve done light-detection experiments with tawny owls, which show that on the whole they could detect lower light levels than humans. They also have much larger eyes, compared with other birds. In fact their eyes are much the same size as ours, but with larger pupils, letting in more light. They’ve worked out, I don’t know how, that the image on an owl’s retina is about twice as bright as on the average human’s.

Jacinta: So their light-sensitivity is excellent, but visual acuity – not half so good as the wedge-tailed eagle’s?

wedge-tailed eagle - world's acutest eyes

wedge-tailed eagle – world’s acutest eyes

Canto: Right – natural selection is about adaptation to particular survival strategies within particular environments, and visual acuity isn’t so useful in the dark, when there’s only so much light around, and that’s why barn owls, who have about 100 times the light-sensitivity of pigeons, also happen to have very good hearing – handy for hunting in the dark, as there’s only so much you can see on a moonless night, no matter how sensitive your eyes are. They also learn to become familiar with obstacles by keeping to the same territory throughout their lives.

face of a barn owl - 'one cannot help thinking of a sound-collecting device, quoth researcher Masakazu Konishi

face of a barn owl – ‘one cannot help thinking of a sound-collecting device’, quoth researcher Masakazu Konishi

Jacinta: So they don’t echo-locate, do they?

Canto: No, though researchers now know of a number of species, such as oilbirds, that do. Barn owls, though, have asymmetrical ear-holes, one being higher in the head than the other, which helps them to pinpoint sound. It was once thought that they had infra-red vision, because of their ability to catch mice in apparently total darkness, but subsequent experiments have shown that it’s all about their hearing, in combination with vision.

Jacinta: Well you were talking about those amazing little brains of birds in general, and I must say I’ve heard some tales about their smarts, including how crows use cars to crack nuts for them, which must be true because it was in a David Attenborough program.

Canto: Yes, and they know how to drop their nuts near pedestrian crossings and traffic lights, so they can retrieve their crushed nuts safely. The genus Corvus, including ravens, crows and rooks, has been a fun target for investigation, and there’s plenty of material about their impressive abilities online.

seeing is believing

seeing is believing

Jacinta: So what other tales do you have to tell, and can you shed any light on how all this cleverness comes in such small packages?

Canto: Well Birkhead has been studying guillemots for years. These are seabirds that congregate on cliff faces in the islands around Britain, and throughout northern Europe and Canada. They’re highly monogamous, and get very attached to each other, and thereby hangs another fascinating tale. They migrate south in the winter, and often get separated for lengthy periods, and it’s been noted that when they spot their partner returning, as a speck in the distance, they get highly excited and agitated, and the greeting ceremony when they get together is a joy to behold, apparently – though probably not as spectacular as that of gannets. Here’s the question, though – how the hell can they recognise their partner in the distance? Common guillemots breed in colonies, butt-to-butt, and certainly to us one guillemot looks pretty well identical to another. No creature could possibly have such acute vision, surely?

Jacinta: Is that a rhetorical question?

Canto: No no, but it has no answer, so far. It’s a mystery. It’s unlikely to be sight, or hearing, or smell, so what is it?

Jacinta: What about this magnetic sense? But that’s only about orientation for long flights, isn’t it?

Canto: Yes we might discuss that later, but though it’s obvious that birds are tuned into their own species much more than we are, the means by which they recognise individuals are unknown, though someone’s bound to devise an ingenious experiment that’ll further our knowledge.

Jacinta: Oh right, so something’s bound to turn up? Actually I wonder if the fact that people used to say that all Chinese look the same, which sounds absurd today, might one day be the case with birds – we’ll look back and think, how could we possibly have been so blind as to think all seagulls looked the same?

Canto: Hmmm, I think that would take a lot of evolving. Anyway, birds are not just monogamous (and anyway some species are way more monogamous than others, and they all like to have a bit on the side now and then) but they do, some of them, have distinctly sociable behaviours. Ever heard of allopreening?

Jacinta: No but I’ve heard the saying ‘birds of a feather flock together’ and that’s pretty sociable. Safety in numbers I suppose. But go on, enlighten me.

Canto: Well, allopreening just means mutual preening, and it usually occurs between mates – and I don’t mean in the Australian sense – but it’s also used for more general bonding within larger groups.

Jacinta: Like, checking each other out for fleas and such, like chimps?

Cant: Yeah, though this particular term is usually reserved for birds. Obviously it serves a hygienic purpose, but it also helps calm ruffled feathers when flocks of colonies live beak by jowl. And if you ever get close enough to see this, you’ll notice the preened bird goes all relaxed and has this eyes half-closed, blissed-out look on her face, but we can’t really say that coz it’s anthropomorphising, and who knows if they can experience real pleasure?

Jacinta: Yes, I very much doubt it – they can only experience fake pleasure, surely.

Canto: It’s only anecdotal evidence I suppose, but that ‘look’ of contentment when birds are snuggling together, the drooping air some adopt when they’ve lost a partner, as well as ‘bystander affiliation’, seen in members of the Corvus genus, all of these are highly suggestive of strong emotion.

Jacinta: Fuck it, let’s stop beating about the bush, of course they have emotions, it’s only human vested interest that says no, isn’t it? I mean it’s a lot easier to keep birds in tiny little cages for our convenience, and to burn their beaks off when they get stressed and aggressive with each other, than to admit they have feelings just a bit like our own, right? That might mean going to the awful effort of treating them with dignity.

Canto: Yyesss. Well on that note, we might make like the birds and flock off…

how the flock do they do that?

how the flock do they do that?

Written by stewart henderson

November 13, 2015 at 12:06 pm