Can birds fly in clouds?
ENTREPPRUNEUR
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Now one of two things is going on here. Either in each of the cases mentioned the birds were actually picking up visual cues - maybe not enough to allow you to fly at aircraft speeds - or they genuinely can maintain spatial orientation without gyros, perhaps even without any kind of 'inertial platform'(ie perhaps by aerodynamic means). If this is so we ought to find out what these techniques are and apply them to aircraft.
PPRuNeaholic
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Back in the days before I was deemed brave enough to fly in cloud, I let the pidgeons tell me when it was okay to fly. If they were on the ground (or in the trees), I was on the ground.
They always seemed to be able to sense when the weather was improving too. So, as soon as they got airborne, so did I. Only ever got caught out once that way...
They always seemed to be able to sense when the weather was improving too. So, as soon as they got airborne, so did I. Only ever got caught out once that way...
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We hit a bird one cloudy night , IMC around 15,500' , WX was not really convective so I guess he was not sucked up there ...
Made a hole to the radom , part of him was in , brown dark feathers.
Made a hole to the radom , part of him was in , brown dark feathers.
Avoid imitations
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Some birds, i.e. swifts, are so specialised that they never deliberately land on the ground and apparently only come down at all in order to nest. It is reported that they eat, mate and sleep on the wing. They also migrate between Europe and Africa so it is highly likely that they do occasionally enter cloud whilst asleep (rather like some pilots I know)!
If they do come to earth they cannot take off again because their legs are so short and under-developed. They must land on a vertical surface such as a cliff face and launch themselves downwards to become airborne again. All their toes face forwards to allow them to grasp vertical surfaces, unlike other birds which have two forwards and two backwards or three forwards and one backwards.
I got to handle one of these fascinating birds for a few minutes many years ago, when I rescued it from our loft after it fell inside. It had been there for more than a day (my mother thought we had a rat up there and I was sent up through the trap-door to deal with it). I remember being surprised how big it was.
Initially I put it on the back lawn and at first I thought it was injured because it just scrabbled around. However, after I hand-launched it, it proved it was absolutely fine and it circled around my head for quite a while as if to acknowledge its thanks.
Yesterday I saw quite a few around and above cloud, in heavy rain at about three thousand feet.
ShyT
If they do come to earth they cannot take off again because their legs are so short and under-developed. They must land on a vertical surface such as a cliff face and launch themselves downwards to become airborne again. All their toes face forwards to allow them to grasp vertical surfaces, unlike other birds which have two forwards and two backwards or three forwards and one backwards.
I got to handle one of these fascinating birds for a few minutes many years ago, when I rescued it from our loft after it fell inside. It had been there for more than a day (my mother thought we had a rat up there and I was sent up through the trap-door to deal with it). I remember being surprised how big it was.
Initially I put it on the back lawn and at first I thought it was injured because it just scrabbled around. However, after I hand-launched it, it proved it was absolutely fine and it circled around my head for quite a while as if to acknowledge its thanks.
Yesterday I saw quite a few around and above cloud, in heavy rain at about three thousand feet.
ShyT
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An interesting collection of responses.
Perhaps they can achieve it though the following...
Direction - Using the earths magnetic field
Altitude - well they would know the pitch through airspeed, maybe air pressure tells them that they are at a certain altitude?
And maybe shadows which we can't see when in clouds helps them too. Even in the darkest clouds there is some form of light therefore some shadow. Perhaps birds' eyes are sensitive enough to use this.
Any thoughts on this? Are there any closet ornithologists amongst us?
Perhaps they can achieve it though the following...
Direction - Using the earths magnetic field
Altitude - well they would know the pitch through airspeed, maybe air pressure tells them that they are at a certain altitude?
And maybe shadows which we can't see when in clouds helps them too. Even in the darkest clouds there is some form of light therefore some shadow. Perhaps birds' eyes are sensitive enough to use this.
Any thoughts on this? Are there any closet ornithologists amongst us?
Don Quixote Impersonator
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Stallie
But how do they get the local and area QNH?
And I do hope they are flying quadrantal levels
[ 19 July 2001: Message edited by: gaunty ]
But how do they get the local and area QNH?
And I do hope they are flying quadrantal levels
[ 19 July 2001: Message edited by: gaunty ]
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Not a closet ornithologist, but didn't someone once post a question asking if anyone knew of any good books about the flight of birds? I seem to recall that it received no (or few) replies. 
OzEx - on a related note, I've used birds to gauge when it was safe to go outside. The last (and it was minor) hurricane we had, six or seven years ago, arrived after midnight and was moving out of the area by mid-morning.
I have four large oak trees on my property, and as you can imagine, quite a few branches were down. I went out to pick them up after I heard the birds start singing, and saw them out and about again. They seemed to know when the worst of the storm had passed.
OzEx - on a related note, I've used birds to gauge when it was safe to go outside. The last (and it was minor) hurricane we had, six or seven years ago, arrived after midnight and was moving out of the area by mid-morning.
I have four large oak trees on my property, and as you can imagine, quite a few branches were down. I went out to pick them up after I heard the birds start singing, and saw them out and about again. They seemed to know when the worst of the storm had passed.
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Just some food for thought. Birds can see UV light, and UV passes through clouds (you can still get sunburn on a cloudy day :o ), so maybe they see UV reflections and shadows, and use that to help fly/nav through cloud?
The same quesion could by asked about deep sea fish. Its pitch black, how do they know which way is up, and how do they nav. Pressure differences and magnetic fields perhaps (same as birds?)
The same quesion could by asked about deep sea fish. Its pitch black, how do they know which way is up, and how do they nav. Pressure differences and magnetic fields perhaps (same as birds?)
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I cannot quote the references - but from memory :
Birds can and do fly in IMC. This is particularly true of the migrating versions. IMC / Cloud penetrations are unavoidable and they will climb before making IMC so that they can use what I believe is termed a Dihederal Glide. Notwithstanding that birds have a sense of the Earth's Magnetic Field (proven) to a sensitive enough degree to resolve the DIP component is unproven.
But the glide is a fact - they will hold their wings at an angle and sense sideslip on the primaries and correct. This ensures that they keep the Blue Side Up even in IMC. If the IMC duration is prolonged they go into a power / glide / power / glide routine. Bad turbulence is a problem, but lift in moderate nimbus activity is a bonus I would suppose.
There are lots of birdstrikes and sightings in IMC and at night. But then if we really understood the mechanics of bird flight my Boeing would probably have feathers.
MG
Birds can and do fly in IMC. This is particularly true of the migrating versions. IMC / Cloud penetrations are unavoidable and they will climb before making IMC so that they can use what I believe is termed a Dihederal Glide. Notwithstanding that birds have a sense of the Earth's Magnetic Field (proven) to a sensitive enough degree to resolve the DIP component is unproven.
But the glide is a fact - they will hold their wings at an angle and sense sideslip on the primaries and correct. This ensures that they keep the Blue Side Up even in IMC. If the IMC duration is prolonged they go into a power / glide / power / glide routine. Bad turbulence is a problem, but lift in moderate nimbus activity is a bonus I would suppose.
There are lots of birdstrikes and sightings in IMC and at night. But then if we really understood the mechanics of bird flight my Boeing would probably have feathers.
MG
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Saw a magpie do an ABSOLUTELY PERFECT stall turn at about 30 feet a few days ago. Of course he was pulling some evasive manouevers to break away from the 3 bandits on his tail... you'll be happy to know he was successful, and lived to continue his air-combat for another day.
OK, now if a bird claps its wings over its back (just asume it can) then it would fall body first with wings trailing - i.e. pendulum effect could have something to do with it. I figure it would just pile on a heap of dihedral, and alter it to suit. Remember it can feel how much lift each wing is producing. If it has some dihedral on then when one wing has more lift it's obviously banking so it corrects. It also knows when it's going to stall too, its feathers will get all ruffled or something, and it squaks to simulate the stall warning horn...
and will compensate with its tail to alter pitch.
This is all a hypothesis, but I'd tend to go more with this possibility that it sensing magnetic fields and seeing UV light. Not saying anyone's wrong, just my thoughts.
Turbofan
P.S. I've also seen a hawk do a few great snap-rolls when I snuck up on it in a Blanik (glider).
Good question Stallie.
OK, now if a bird claps its wings over its back (just asume it can) then it would fall body first with wings trailing - i.e. pendulum effect could have something to do with it. I figure it would just pile on a heap of dihedral, and alter it to suit. Remember it can feel how much lift each wing is producing. If it has some dihedral on then when one wing has more lift it's obviously banking so it corrects. It also knows when it's going to stall too, its feathers will get all ruffled or something, and it squaks to simulate the stall warning horn...
and will compensate with its tail to alter pitch. This is all a hypothesis, but I'd tend to go more with this possibility that it sensing magnetic fields and seeing UV light. Not saying anyone's wrong, just my thoughts.
Turbofan
P.S. I've also seen a hawk do a few great snap-rolls when I snuck up on it in a Blanik (glider).
Good question Stallie.
Not so N, but still FG
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What a good thread. Pax D, it was me who posted a while back re books on bird flight. As you say, there were few replies, and searches on Amazon, at the London Library etc have drawn blanks, but this thread is producing some interesting replies, as well as a few half decent jokes.
Re the aerobatic Magpie ace, surprising to see a stall turn as an evasive manoeuvre (try it in CFS and even the exceedingly stupid computer-controlled badguys will get you). Presumably the bandits expected him to split-S and he threw them off with an unexpected move. Always thought magpies were boom-zoomers rather than dogfighters, but perhaps this was the P-38 variant with the combat flaps?
Re the aerobatic Magpie ace, surprising to see a stall turn as an evasive manoeuvre (try it in CFS and even the exceedingly stupid computer-controlled badguys will get you). Presumably the bandits expected him to split-S and he threw them off with an unexpected move. Always thought magpies were boom-zoomers rather than dogfighters, but perhaps this was the P-38 variant with the combat flaps?
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IR sensors can be used to see through smoke. I don't know about UV but could birds' IR vision (if they have it) enable them to see through at least thin cloud?
Some birds like swifts seem to spend quite a lot of time in the air with wings folded, between short but fast bursts of flapping. I suppose this is an advantage all birds have - they can at will dump all lift. As long as they have sufficient semi-circular canal apparatus to sense gravitational acceleration downwards then all they have to do know which way is down in IMC is stop flying, sense in which way they accelerate i.e. downwards and take whatever action is necessary to stop it.
Some birds like swifts seem to spend quite a lot of time in the air with wings folded, between short but fast bursts of flapping. I suppose this is an advantage all birds have - they can at will dump all lift. As long as they have sufficient semi-circular canal apparatus to sense gravitational acceleration downwards then all they have to do know which way is down in IMC is stop flying, sense in which way they accelerate i.e. downwards and take whatever action is necessary to stop it.
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All is not lost FNG (and others)!
Go to http://www.abe.com
Click on "detailed search" on the left and then enter "bird flight" in the keywords section.
I've only looked at the first page of listings returned, but it looks like there are books on bird flight out there. And because the site lists books offered by booksellers from around the world, you may be able to order one from a seller close to home.
And if someone orders one of these books, please tell us if you find the answer to Stallie's question (and some of the others posted here)!
Go to http://www.abe.com
Click on "detailed search" on the left and then enter "bird flight" in the keywords section.
I've only looked at the first page of listings returned, but it looks like there are books on bird flight out there. And because the site lists books offered by booksellers from around the world, you may be able to order one from a seller close to home.
And if someone orders one of these books, please tell us if you find the answer to Stallie's question (and some of the others posted here)!
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Seem to recall an excellent Beeb 2 programme about the world through other critters eyes. They suggested that UV + Polarised light had a lot to do with it.
Also enabled hawks to spot recent mouse trails.....
[ 19 July 2001: Message edited by: SSC ]
Also enabled hawks to spot recent mouse trails.....
[ 19 July 2001: Message edited by: SSC ]
I was soaring with a seagull one day while flying a glider. We both thermalled up into the base of a large cumulus, whereupon we collided shortly after. Yes, they do fly in clouds, but I'm not sure about the seeing bit! 