Can birds fly in clouds?
 

Stooging along at 4000' over that strip of coral off the coast here playing the mental vagabond, I wondered if birds actually can or do fly in cloud.

Are their ears and semicircular canals set up the same way as ours? Can they sense acceleration of less than 0.05m/s2 (our threshold)?

What do they do when it's all foggy for days on end in say the UK? or drizzling and rain with no horizon to speak of...surely not sit on the ground and starve.

Thanks

Bored in Cairns

I believe that an albatross can fly while it sleeps, but that might be an urban myth. If it is true, I guess flying in cloud wouldn’t be too dissimilar. However, flying around mountainous areas may inhibit their navigational prowess.

I’m sure there are some far more knowledgeable ppruners out there who will know the answer.

Onya stallie thats a very very interesting question!!

I doubt they can any more than we can.

More to the point - why they would possibly want to? :confused:

The whole subject of bird flight is very interesting but it is difficult to find much published information on the subject outside specialist scholarly journals. Apparently Lielenthal wrote about bird flight but I have not located his book. I once posted a question here asking whether any bird can aerobat or fly inverted but no-one knew the answer. As to birds flying IMC, I read in some tome (I think it was "Weather Flying" by some US bloke)that it is believed that certain species of migratory birds may be able to fly in cloud, but little is known of this, as with other aspects of bird nav techniques.

Birds normally consider clouds as obstacles & would not fly through. However, hawks & vultures have been reported to do so by glider pilots. These 2 species happen to have the best "eyesight" of all, so it might as well depend on the thickness of the cloud.

MF

They do fly in cloud, it's true.

Trouble is they shut their eyes when they do it which makes it damn near impossible for us to see them doing it!

Hope that clears it up!

And do they suffer from airframe icing? :)

Saw a "V" formation of ducks fly into a cloud once, then come tumbling out of the bottom! Whether that was due to the downdraft or the lack of the ability to fly in cloud, I am uncertain.

The threshold of perception has nothing to do with it, however - the laws of physics apply to all of the Earth's creatures! While I am certain that birds don't have spinning gyros in their heads, whether they can sense the Earth's magnetic field to the accuracy required to stay upright is another question - and I doubt that they do - so my answer is "no".

And are they CAT II or may be even CAT IIIC?

What we were taught in behavioural biology is that some of the larger birds that migrate can 'navigate' through various means including:
Using the sun/ stars
Sensing earths magnetic fields
Accurate time keeping
Orientation info from semi-circular canals
I don't see why the larger birds couldn't fly through clouds..
The smaller birds that 'pilot', not navigate might have a problem though, as they use visual clues for direction finding. I might crack open the textbook if I can find it..
Tom.

Edited to make sense..

[ 16 July 2001: Message edited by: tom775257 ]

Pigeons can fly in cloud but usualy only do so to avoid Dastardly,Mutley,Clunk et al.
Muttley you snickering floppy eared hound,
When courage is needed, you're never around!
Those medals you wear on your moth-eaten chest,
Should be there for bungling at which you are best!
So, Stop The Pigeon, Stop The Pigeon,
Stop The Pigeon, Stop The Pigeon,
Stop The Pigeon, Stop The Pigeon
Stop that Pigeon How ?
Nab him - jab him - tab him - grab him,
Stop that pigeon now!

You silly, stop sneaking it's not worth the chance,
For you'll be returned by the seat of your pants!
And Clunk, you invent me a Thingamybob,
That catches that pigeon or I lose my job!
So, Stop The Pigeon, Stop The Pigeon,
Stop The Pigeon, Stop The Pigeon,
Stop The Pigeon, Stop The Pigeon
Stop that Pigeon How ?
Nab him - jab him - tab him - grab him,
Stop that pigeon now!

Ravens are the only birds that I know can fly inverted (or upside down as we birdwatchers say)

I've seen ducks above cloud (stratus top 2000ft as far as the eye can see!) so they might have flown through it.

Also in answer to FNG, I recently saw a Canada Goose do a very impressive barrel roll to avoid my Fokker 100 last month. I've also seen a swallow do a very graceful spin, but as it had just bounced off the leading edge of the TB-10 I was flying, I doubt it counts! ;)


spelling!

[ 16 July 2001: Message edited by: Flap40 ]

Well, a collegue of mine had a birdstrike while flying IMC. It made quite a lot of damage to his F70. Could have been a swan or big bird from sesamestreet. But one thing was for sure: that bird was flying IMC! Made me wonder how that bird did it...

I was sitting on a lake once with a Beaver on floats, waiting for the weather to clear. The ceiling was maybe a hundred feet, and a couple hundred yards viz. All of a sudden, I heard a bunch of geese honking, then you could hear wingbeats, followed by splashing out on the water. The fog cleared in an hour or so, and there were about twenty Canada geese swimming around just down the shore.
I've caught up to a flock of geese on top of a cloud layer with an Otter. (Took awhile :p ) So I'd say yes, some birds fly in cloud.

Stallie - what's wrong? Are backpackers out of season? :D

In a lighter vein, those of you who have replied to this thread might also enjoy

CATIII (and duck too)
Ever thought how CATIII got its name? http://www.pprune.org/cgibin/ultimat...c&f=4&t=004616

Nothing on bird navigation in my Audubon Handbook How To Identify Birds, but there were 14 pages on flight behaviour, including . . .

Soaring
To save energy during long migrations, or while circling high in the air and searching for food, many birds soar on outstretched, motionless wings. When air currents are deflected upward by long mountain ridges, some of these birds can travel for miles without a single wingbeat.

Dihedral Soaring
While most soaring birds hold their outstretched wings flat, a few raptors soar with the wings held in a shallow angle or V called a dihedral - a term borrowed from aviation. As these birds soar on dihedral wings, the usually appear unsteady, swaying from side to side. [Made me think - now, just what came first, the dihedral winged bird or the dihedral winged aeroplane? :rolleyes: ]

Beeline Flight
Some birds have a regular, rhythmic, almost mechanical wingbeat and a perfectly straight flight path, as if the bird were being pulled rapidly along a taut wire. This "beeline" flight is characteristic of some large birds with relatively slow wingbeats, as well as some of the tiny hummingbirds.

Flying with Rapid Wingbeats
Smaller birds tend to have more rapid wingbeats than larger ones, but some birds have fast wingbeats because their wings are very small or short in relation to the size of the body. Although swifts have long wings, the bend of the wing is very close to the body, and they also beat their wings rapidly.

Stiff-winged Flight
When some seabirds flap their wings in normal flight, the angle of the wing does not bend, creating a striking, stiff-winged effect. The birds use their stiffly helf wings to coast on small air currents over the waves. [Illustrated with photographs of albatrosses, albatrossi, whatever :) ]

Follow-the-leader Flapping
Some water birds that fly in lines may coast for several seconds without flapping their wings. When the lead bird flaps its wings, each bird in the line then flaps its wings in turn, as if copying the bird just in front of it. A wave of flapping moves down the line.

Simulaneous Banking
In some species, the birds in a fast moving flock bank in a highly coordinated way. All the birds change position at almost exactly the same instant. A distant flock of sandpipers seems to appear and disappear, as the birds reveal their dark underparts then their pale undersides to the observer.

There is another mystery I have been racking my brains with. How does a large flock of birds fly in perfect formation? :confused:

I believe fish achieve this by sensing minute pressure changes in the water created by the surrounding fish. Air on the otherhand doesn't allow for such rapid pressure waves to travel through it, so how do a flock of 50 or so birds achieve simultaneous banking?

I once saw an Owl fly inverted thru a barb wire fence, I dont know if it managed to roll out tho. The car had gone past by then, and I think the air blast from the car had something to do with the aerobatics. Does this count.

Not sure about birds in clouds tho, I've never seen any. :cool:

Never met any birds in cloud but one sad bird story that I read of comes to mind.
The wings of the Razorbill are, for some reason which the experts cannot determine, very slowly decreasing in size.
To compensate for this they have to fly faster and this means larger breast muscles to increase the flapping rate. Increase size of breast muscles puts up the weight and thus the wing loading which requires more speed and bigger breast muscles for faster flapping, and so on and so on. The experts did not offer a prediction as to when the poor thing would finally be grounded like the penguin.

Saw a tv documentary a number of years ago that showed birds doing aeros, aparently just for the fun of it.

Also saw a crow do a barrel roll and looking really pissed off afterwards when it got caught in the vortex of a rotating 757.

They certainly fly at night as a late bird of unknown manufacture can vouch after denting my radome at 500ft on the approach.

I reckon that they all do an IR at a very early age otherwise how could they fly in controlled airspace?

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.

Not ever seen them in cloud, but have seen birds as high as 15000' over India and understand that they do go higher. Anybody add to that?
Cheers
mcdhu

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... :eek: :D

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.

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

So do they set TA/RA before they fly anywhere? I reckon thats why there are usually flocks of birds at airports, they are vor/dme equipped.

Someone else said they use stars to navigate.

Do they use sids as well?

Hmm.

NS - Very good,never bothered to learn the words myself,classic series though. :p

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? :cool:

Stallie
But how do they get the local and area QNH?
And I do hope they are flying quadrantal levels :eek:

[ 19 July 2001: Message edited by: gaunty ]

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.

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?) :confused:

Frigate Birds do fly in clouds. I observed on one ocassion over 200 frigate birds flying into a weak ITCZ. :eek:

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
;)

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.

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? :D

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.

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)! :D

Thanks for that. I had found alibris to be a good source of old and/or obscure books but had not previously tried abe.

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 ]

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! :rolleyes: