• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

How do birds know that another bird is dead? (1 Viewer)

ChrisKten

It's true, I quite like Pigeons
Because I've fed the birds in my garden for years, and because there's loads of birds (60+ Pigeons - 30-50+ Sparrows - 20-70+ Starlings - and others), I've often seen dead birds. Sometimes the bird is half-eaten by a Sparrowhawk that was spooked (they visit often), other times the bird died from illness or injury. And there's also times when I've no idea how the bird died. However, I don't know that the apparently-lifless bird is dead until I go and check it. Is it warm? - is it stiff? - has it got a heartbeat? - does it flinch if I prod it? are the eyes lifeless? etc. And even then, I'll probably wait a while before I bury it (if it died from injury or Sparrowhawk I'd leave it until dark), just to be sure.

Birds, OTOH, know instantly when another bird is dead. If a sick Pigeon dies while the males are squashing it (males try to mate with very sick birds, but that's another story), they stop and walk away. They never return and try again, even though the urge to mate was apparently impossible to resist. Once a bird of any species is dead, other birds have no more interest in it than they do a rock; they either walk around it or over it. I've seen this with dead Starlings, Pigeons, Sparrows, and Collared Doves, and I've seen the same reaction (or lack of any reaction) to the dead bird from every species in my garden. I'm including the Corvids too, as if they don't eat it, they ignore it.

So, bearing in mind that Humans seem to need time and effort to determine whether a bird (or animal) is dead, how do birds know?

I've a few ideas myself, but I'm curious as to what others think.
 
What an interesting question!

Could it be smell, perhaps? Or perhaps the lack of some sort of magnetic wave? Something birds can sense but we can't presumably.
 
A combination of avian psychology & relative size, I would have thought. Unlike us (at least when our better angels are in control), birds aren't going to agonize over whether something is "really" dead, but if it acts dead are going to treat it as such, i.e. as the inanimate object that for all practical purposes it has now become. And that's where relative size comes into it. If we were roughly the same size as the moribund bird, & could walk right up & look it in the eye rather than just prodding it with a foot, it would be a lot easier for us to detect tiny signs of life--slight changes in the eye, minute body movements in connection with respiration, heartbeat, plumage adjustment, whatever. Just off the top of my head on a lazy Sunday morning. I'll be interested in hearing what you & others may have to say.
 
Thanks for replying.

I favour "Something birds can sense but we can't"; although I've a feeling that it's something birds can see that we can't.

I get what Fugl is saying too, but all of the birds in the garden know that the bird is dead (well, they know that it's not a living thing), and often none go anywhere near it, at least not near enough to see anything different. Would a Human be able to tell another Human was dead, just by looking? Or would we need to actually examine the body closely?

Also the other birds seem to know instantly that the bird isn't alive; it's almost like a switch goes off in all of them. They don't need to go near it, or even look at it, it's just no longer a bird. It's not a threat, not a potential mate, not competition for food; it just doesn't exist.

The thing that strikes me is the apparent certainty that the living birds have. I mean there's no doubt that I can see; they don't go and give the dead bird a prod later just to make sure. I'm also curious how the birds would react to a dead Raptor; would there be the same certainty that it was no longer alive? What about a dead Cat? Is it just other birds that they seem to know are dead?

I'll leave it at that for now, as I'm interested in what others have to say, as I'm only really thinking out loud.
 
Interesting. 2 points. One is that in general birds have very good eyes so that they probably needn't get that close to satisfy themselves that an apparently dead bird is actually dead. The second is that birds are very quick to pick up cues from other birds, so that as soon as one individual "realizes" that another is dead (& reacts accordingly) others will presumably instantly notice & follow suit.

With regard to dead birds of prey, 1 found a dead Northern Saw-whet Owl in my backyard some years ago which was totally ignored by the small birds feeding calmly all around it. I didn't see it die (& don't know what it died from or what it was doing in my yard) but it was freshly dead & couldn't have been on the ground for long. Live Saw-whets are definitely feared by small birds & are habitually mobbed by them at their day roosts.
 
Last edited:
Interesting. 2 points. One is that in general birds have very good eyes so that they probably needn't get that close to satisfy themselves that an apparently dead bird is actually dead. The second is that birds are very quick to pick up cues from other birds, so that as soon as one individual "realizes" that another is dead (& reacts accordingly) others will presumably instantly notice & follow suit.

With regard to dead birds of prey, 1 found a dead Northern Saw-whet Owl in my backyard some years ago which was totally ignored by the small birds feeding calmly all around it. I didn't see it die (& don't know what it died from or what it was doing in my yard) but was it freshly dead & couldn't have been on the ground for long. Live Saw-whets are definitely feared by small birds & are habitually mobbed by them at their day roosts.

I'm with you on the eyesight being superior, and distance to the dead bird being less important than it would be to us, but I've still doubts about what they actually see that's different. I'd guess that lack of movement alone wouldn't be enough, as birds (especially birds of prey) can stay pretty still even when awake. Posture would be important I guess, as dead birds tend to be lying flat. But the the birds would have to be (and seem to be) 100% sure that the bird is dead, especially in your example of the dead Saw-whet.

What I'm getting at is, what is it that gives them such certainty in an instant? And what I'm wondering is, is there more to it than what we can imagine from our Human perspective, and with our limited senses? Birds see in Ultraviolet (and apparently 4D colour); what if everything that is alive (and breathes) has a sort of Aura (nothing religious or mystical) that we can't see but birds can?

Just thinking out loud again.
 
I'm with you on the eyesight being superior, and distance to the dead bird being less important than it would be to us, but I've still doubts about what they actually see that's different. I'd guess that lack of movement alone wouldn't be enough, as birds (especially birds of prey) can stay pretty still even when awake. Posture would be important I guess, as dead birds tend to be lying flat. But the the birds would have to be (and seem to be) 100% sure that the bird is dead, especially in your example of the dead Saw-whet.

What I'm getting at is, what is it that gives them such certainty in an instant? And what I'm wondering is, is there more to it than what we can imagine from our Human perspective, and with our limited senses? Birds see in Ultraviolet (and apparently 4D colour); what if everything that is alive (and breathes) has a sort of Aura (nothing religious or mystical) that we can't see but birds can?

You say that certainty of death has to be 100%, but speaking generally I don’t know if this is true, at least in most cases. In purely Darwinian terms (natural selection), it might be best for birds to settle for some lesser degree of certainty and carry on with feeding & other vital activities rather than waste time & energy in profitless investigation of dead creatures. In other words, to just play the odds, making a snap decision & going about normal activities without frittering away time & attention on inessentials. I certainly don't think we need posit the existence of unknown sensory capabilities to account for any of this. All highly speculative one way or the other, of course.
 
Last edited:
Have seen several states that have sites that offer advice to homeowners and the like
regarding various "bird problems"...ie.woodpeckers on siding,crows in the vegetable garden,etc.
Owl decoys are mentioned and is suggested that they not be employed,
unless moved frequently.Reason being,(maybe not verbatim on my part)
but simply put,after a short time live birds know the "jig is up" so to speak.

See very few waterfowlers with strings of calls around the neck
as in years past,nowdays its bags full of robo-decoys,every fowler Ive talked with
says "robos" more effective than calling.
 
Have seen several states that have sites that offer advice to homeowners and the like
regarding various "bird problems"...ie.woodpeckers on siding,crows in the vegetable garden,etc.
Owl decoys are mentioned and is suggested that they not be employed,
unless moved frequently.Reason being,(maybe not verbatim on my part)
but simply put,after a short time live birds know the "jig is up" so to speak.

See very few waterfowlers with strings of calls around the neck
as in years past,nowdays its bags full of robo-decoys,every fowler Ive talked with
says "robos" more effective than calling.

Some interesting theories on this thread but i was wondering about decoying and that doesnt really seem to fit in with any of these theroies.
If birds really do have the ability to instantly know another bird is dead then surely they would know that a decoy isnt even a real bird which of course at times they do but decoys do still often work and the thing thats really got me wondering is the fact that dead birds used as decoys will often be more effective than artificial decoys suggesting that they dont know that they are dead. That said one live bird will always be more attractive than any amount of dead or articficial decoys so maybe there is something in this but it doesnt seem to be clear cut that birds will always instantly recognise a dead bird from a live one.
 
Yes, Fugl; I was stretching it a bit with 100%, maybe 90% would've been better|=)|

The "Decoy" aspect is something I'd not considered. I don't know much about Shooting, so I'm not sure how it all works.

Are the target birds attracted from nearby? Or would they be flying over and see the decoy? If they're attracted from a distance, then I suppose they'd need to get closer to know it was just a decoy?

Are the target birds different from Pigeons/Starlings/Crows/etc? Are they all waterfowl? Maybe not all bird species have the same awareness of a dead bird? If they don't; then I guess the question is, "Why not?".

My "Aura" idea seems impossible now, as no decoy would ever work.

I know it's all guesswork, but I still think it's interesting to speculate.
 
I was thinking mainly about Pigeons but i suppose most of the general principles are the same no matter what the species. Most birds would be initially fooled from a distance but they still need to come quite close in the end and will infact happily land amongst decoys if allowed to. As you say the aura idea doesnt seem to quite fit but as i said there's definitely something about a live bird that is more attractive than a dead or artificial one so i do think there could be something in this that we dont yet understand. I do know that movement can play in big part in decoying hence the earlier mentions of 'robo decoys' being more effective and this may go someway to answering why live birds are most likely to attracte other birds.
Certainly an interesting subject and i quite like the idea that birds have senses or powers we know nothing about.
 
at least some birds don't seem to care...there are reports of mallards attempting to mate with dead ducks for instance
 
A bit of a different situation, as it is mammals. A few years ago, I had a rabbit in the garden with a fairly advanced case of myxymatosis (if I have spelled it right). My cat was a fairly enthusiastic rabbit catcher but he and the cat next door wouldn't go near it. They sat several yards away, eyes like saucers. Eventually I called the RSPCA for advice and they said to put a cardboard box over it until they were able to come and take it away. Poor thing was just about blind and deaf. Cats still wouldn't go near. Possibly it smelled bad and it obviously looked odd to them. Most birds can't smell.

Pat
 
Much of birds life is reacting to simple visual signals of posture and movement. Eg: raises tail -> mate with it (even a stuffed dummy put by researcher). Something sings -> attack it (even a loudspeaker put by researcher).

Birds usually don't use smell or any "magnetic" or telepathic waves. And actually usually have little understanding of concepts like "bird" or "mate" or "live" or "dead". Their often very complex behavior is often a set of very basic signal -> reaction rules.

Some birds, like ravens and parrots are much more intelligent, but if you ask simple question "why bird react differently to dead one" its it.
 
at least some birds don't seem to care...there are reports of mallards attempting to mate with dead ducks for instance

I've a feeling that Mallards are a special case|=)|

A bit of a different situation, as it is mammals. A few years ago, I had a rabbit in the garden with a fairly advanced case of myxymatosis (if I have spelled it right). My cat was a fairly enthusiastic rabbit catcher but he and the cat next door wouldn't go near it. They sat several yards away, eyes like saucers. Eventually I called the RSPCA for advice and they said to put a cardboard box over it until they were able to come and take it away. Poor thing was just about blind and deaf. Cats still wouldn't go near. Possibly it smelled bad and it obviously looked odd to them. Most birds can't smell.

Pat

I did think about mentioning Mammals, but I decided against it. I remember watching a Documentary where a young mammal (I really don't recall the species) was laying beside a piece of meat. It turned out the "piece of meat" was what remained of it's mother. The mother was eaten by predators, but the smell of the mother remained on the "meat". So I thought that it might be different for Mammals with their sense of smell.

Much of birds life is reacting to simple visual signals of posture and movement. Eg: raises tail -> mate with it (even a stuffed dummy put by researcher). Something sings -> attack it (even a loudspeaker put by researcher).

Birds usually don't use smell or any "magnetic" or telepathic waves. And actually usually have little understanding of concepts like "bird" or "mate" or "live" or "dead". Their often very complex behavior is often a set of very basic signal -> reaction rules.

Some birds, like ravens and parrots are much more intelligent, but if you ask simple question "why bird react differently to dead one" its it.

Of course we don't really know what Birds understand; we devise tests based on our understanding of the world, and interpret the results. But we can never really know what another species (or Human) is thinking.

As for what birds see, we can't know that either; they see in 4D Colour, we see in 3D Colour.

I'm also pretty sure that a Pigeon will attempt to mate with a paralysed Pigeon, but not with a dead one. There's no movement from either bird, no signals etc, but the Pigeon attempting to mate knows the difference.
 
A bit of a different situation, as it is mammals. A few years ago, I had a rabbit in the garden with a fairly advanced case of myxymatosis (if I have spelled it right). My cat was a fairly enthusiastic rabbit catcher but he and the cat next door wouldn't go near it. They sat several yards away, eyes like saucers. Eventually I called the RSPCA for advice and they said to put a cardboard box over it until they were able to come and take it away. Poor thing was just about blind and deaf. Cats still wouldn't go near. Possibly it smelled bad and it obviously looked odd to them. Most birds can't smell.

Pat

But the Mammal Society Weasel and Stoat guide says Stoats focus on myxomatosis victims in late summer (when the disease peaks). I don't know if foxes are put off. Stoats are expert scent followers (so are Weasels - I once watched a Weasel tracking a Hazel Dormouse by scent in the dark) but presumably the availability of easy meat outweighs the scent issues.

John
 
Warning! This thread is more than 12 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top