Only one question, you can answer, because you took the photo. Were they taking off or landing? A while ago I googled about how you can tell by looking at the angle of the wings and tell the difference, just like the flaps on an aircraft.Looking at the feet facing forward, acting like brakes, were they preparing to land?
Something I found on Wiki:
Birds and airplanes face into the wind when taking of or landing so they can take advantage of wind speed. If the wind were at their backs, they would not have the control they have when facing into it. But differences exist here too: While large birds need a prolonged takeoff run to become airborne, small birds can jump straight into the air on takeoff; they can generally achieve lift from zero air speed. Larger birds can fly at speeds within a minimum and maximum range, but they cannot take flight at zero air speed. Therefore, larger birds need to generate air speed before they can take off. The often run over the ground or water until they reach the minimum air speed needed to take flight.
So, were the Pelicans "running to take off", or slowing down "to land"?
I’m intrigued by this. Have a look at the way those fingers at the end of the wings are open? To gather maximum speed shouldn’t they be closed? Some time ago I found a chart displaying pictures of the wings of birds during takeoff and landing. I wish I could find them again. It was fascinating. It showed the position of the wings using updraft and downdraft (if that’s the right word for it?), slow down and speed up. If anyone can find something like it, I’d love to see it.
Nice shots Alan. They are a great bird to watch, once they take off they seem to fly around with no effort.
M-L all i can say is when they take off they have to hop on the water several times to take off (as shown in the second shot) as for the wings i have no idea, but here is a link showing take off and landing pics.
I'd expect that the greater the wing surface area the greater the lift to enable take off. That might explain the spread primary wing feathers in BajanAlan's photo.
On a number of occasions I've watched wedge-tailed eagles taking off & the power that goes into achieving lift from their spread wings as they slowly gather speed is awesome. That's one large bird that doesn't need a run up before taking off.
I know all that, but there are rules just like there are rules in aviation, the angle the bird holds the wings during takeoff and landing is most important. Just like on an aircraft, if you would put the flaps on the wings at the wrong angle , you would crash land, or never get off the ground. That's what I'm after. You can actually tell by looking at their wings what the birds are doing. (I was hoping someone could tell me?)
Wow, this topic has really got deep now! So, for M-L’s benefit especially, I’ll throw in my two penneth!
I’m certainly no expert on ornithology – but I do know a little bit about aeroplanes so I’ll try to cover as many of the topics there as I can.
Yes, birds and aeroplanes normally take-off as much as possible into wind to shorten the take-off run. However, that is not always the case. Obviously, if a bird takes fright near the upwind end of a lake it will sacrifice a short take-off in order to just escape. After-all, it is better to be rapidly getting away from you predator than to be heading towards him! For expedience, aircraft will sometimes take-off with a slight tailwind with the knowledge that they are going to use up more runway in doing so (and will require a lot more runway if they decide to abort the take-off and stop!) For example, depending on the model, a Boeing 767 can accept up to 10 or 15 knots of tailwind.
Fixed wing aircraft need a particular amount of air passing over their wings to generate the required amount of lift. To do that, they have to move forward faster and faster until they achieve that speed. The engines simply propel the aircraft forward and the wings simply lift it. However, a bird uses its wings as both engine AND lift.
For most large birds, I suspect that, initially, the wings are used to propel forwards (and waterbirds use their feet as paddles to assist with gaining that speed). Once fast enough to get airborne and remove the drag of ground or water it will still flap like crazy to get to full flying speed and then climb away. An aircraft does much the same. An aircraft will apply a lot of power to the engines and will leave the ground just after it gets above its stalling speed – but this speed needs a high wing angle which, in turn makes high drag. The aircraft therefore will retain the high power setting until it accelerates to a more efficient speed and can safely climb away.
M-L mentioned ‘flaps’. On an aircraft, these are used to alter the shape and size of the wing. The bigger and more rounded the top surface of a wing, the greater it’s lift at a given speed. This means that an aircraft (or bird) can take off or land at a slower speed and therefore need less ‘runway’. However, this extra lift comes at a price – extra drag. So, as soon as practical, the aircraft retracts its flaps and a bird reshapes its wing into a more streamlined profile. Incidentally, a pilot relies on sensitive instruments to warn him if he is about to go too slow for the wings to support the aircraft and ‘stall’. A bird has its own, very accurate, stall warning system – its feathers! Just as it is about to stall, the airflow over a wing separates and becomes turbulent. This actually starts to ruffle some feathers on the top of the bird’s wings and ‘tickles’ it – thus warning the bird that it is running out of airspeed!
Smaller birds are able to flap their wings more rapidly and I imagine are able to put much of the energy (engine thrust) into the vertical plane and thus climb away much more quickly and steeply. I guess we could equate a large bird to a lumbering Jumbo and a small bird to a nimble and powerful fighter-jet.
Small aeroplanes have fixed undercarriage. Their wheels are always down which makes for a very simple system. However, once again there is a penalty – that old foe, drag. It is much more efficient to be able to tuck those wheels up in the aircraft out of the slipstream. Birds do the same thing. They lift their legs and tuck them up into a beautifully streamlined position. Just before they land, aircraft lower their landing gear (dangle the Dunlops) to prevent that aweful scraping noise and early retirement. Birds do the same. The most spectacular is when one watches waterbirds gliding in with their webbed feet splayed and angled back like waterskis. This seems to have two purposes; it gives them a controlled touchdown and transition from flying to floating without digging in and flipping over (as would happen with a wheeled aircraft) and the extra drag of such large paddles very quickly reduces their landing roll.
Now, the wing-tip feathers! Looking at the photos I suspect that a Pelican’s tip feathers are spread like that naturally. However, they undoubtedly act like an aircraft’s ailerons. By changing the angle of them (up on one side and down on the other) the wings suddenly have different amounts of lift and one wing will drop while the other rises. Then, like riding a bike, the aircraft or bird will turn. Being on the end of the wings, these feathery ailerons will have the greatest leverage and, I suspect, when the individual feathers are spread slightly it will increase their effectiveness. This is best seen in large birds of pray soaring in thermals or ‘hovering’ as they watch potential prey. Just the wingtips move to control their flight. Aircraft are basically the same.
I hope this covers all of M-L’s concerns! Let me know if you disagree or have alternate theories.
Thanks Roly, that was the best and easy to understand explanation I ever got.I was most interested in the function of the wing-tip feathers, and the way they are used by changing the angle.
sometimes even waterbirds get that "controlled touchdown" wrong. I have seen ducks in a way crash land and topple over.
If this was an aeroplane's wing it would be called 'anhedral' - downwards bending.
This gull was just surfing on the upward air current and looked like it was just hanging there. It was obviously close to the stalling speed. If you look at the top of its wing you can see a couple of feathers lifted up by the turbulence of pre-stall airflow - its own, inbuilt stall warning system.
Wing tip vortices are a huge component of drag. As the higher pressure air under the wing slips around the tip of the wing to the low pressure area on top it forms a powerful vortex - the turbulence which absorbs a lot of energy. Many modern aircraft now have winglets and these help. Only a few percent but, with the price of aviation fuel, every little helps!
Let’s not forget the function of the tail, a bird can spread it , tilt it, shift it up or down, use it as a rudder, to change direction, or slow the bird down
Yes, essentially, dihedral (wings sloping upwards) gives greater stability due to a sort of pendulum effect. This is great until you want to turn or maneuvre - especially in a hurry! It can be TOO stable! Fighters etc actually use the instability of anhedral to increase their maneuvrability - but they are then harder to control. They therefore rely on computers to reintroduce artificial stability to enable the pilot to fly them!
Interestingly, some large aircraft (like the Russian Antonov - 124 and the US Lockheed Galaxy use anhedral wings - but they are high mounted. Luckily for the birds, they can instantly warp their wings to any shape that best suits them at the time!
Also luckily for birds, they don't have to pass any exams on the theory of flight before they take to the air! In fact, it's interesting that, after all these years, there are scientists who are now challenging the conventional theory of flight!!!!!
I think the birds have the right idea and attitude to flight theory! :)
Yes Roly, birds are amazing creatures. And I apologize to Alan for high jacking his post for this discussion. I think it was very interesting, and answered my question .Thanks for the great effort Roly , very much appreciated.
Rolyd, thanks so much for the erudite discussion. Is it the case that the shape of an aircraft's wings promotes faster airflow over the upper wing surface which causes lower airpressure there & thereby generates lift?
Wonderful shots! Pelicans have always fascinated me - must have been all the times watching "Storm Boy" when younger Still learning a lot about all birds, but one thing that always impressed me about Pelicans in particular, is the young apparently "listen" to the parents while still in their eggs, so they can easily identify them when hatched. Probably something a lot of other bird species, I don't know about, do too, but fascinating nevertheless.
Hi Woko, as I said I know very little about birds but I do know a bit about aircraft – or at least I thought I did, until recently!
When they taught me to fly back in 1967, that was, indeed, the theory of flight. Bernoulli’s Principle said basically that if you increase the speed of air you get a decrease in the pressure. Therefore, because of the camber, air going over the top of a wing (or through a venturi like a carburetor) would speed up and therefore drop in pressure. The relatively higher pressure air underneath would then lift the wing up.
That was easily demonstrated by holding the edge of a piece of paper horizontally in front of you and letting it droop away from you, forming a wing’s shape. If you then blow across the top, the paper will rise. Another good one for kids is to dangle a large spoon gently by the very end. Turn on a tap and get a gentle but continuous stream flowing. If you then move the spoon into the water so that the outside of the bowl just touches the stream one would think that the spoon would be deflected away – but that is not the case. The spoon will be ‘sucked’ into the stream! Gently moving back out of the stream, the spoon will pull back until it finally ‘stalls’ and comes free.
That was all quite logical, however, it didn’t account for an aircraft being able to continuously fly inverted! Something else had to be a factor. I don’t know who but someone once said, "With a big enough engine you can make a barn door fly". It certainly needs more power to fly level, inverted. Perhaps it’s just the planning effect – I now have no idea!
In recent years, some scientists have questioned the old theory of flight and I don’t think they have yet to come up with a consensus! It seems that for the past 45 years I’ve been blissfully unaware of what was actually keeping me aloft! Perhaps the birds know the real answer!
We were watching a pelican the other day (may have been at Xmas) gliding low over the water, and assuming they must get a huge amount of lift from the ground effect, as he/she was just gliding effortlessly over the water for ages at about 6-12 inches above the water.
Yes, Alan, I've even seen flying toilet seats - but I've never actually seen a UFO!
Those wings have such beautiful symmetry!
It has never occured to me that (the wings of) flying toilet seats have a beautiful symmerty. Next time one zoooms past me, I will pay more attention to it.
Could the wing tips be spread to allow an "easier" upward beat, ie, it lets the air through, and thus less drag on the wing, less energy, then on the power stroke, they are closed? just a thought!
Great photo! I love pelicans - so graceful. This is a great action shot.
Absolutely love this shot. It really feels 'alive'.
Great shot Alan
Only one question, you can answer, because you took the photo. Were they taking off or landing? A while ago I googled about how you can tell by looking at the angle of the wings and tell the difference, just like the flaps on an aircraft.Looking at the feet facing forward, acting like brakes, were they preparing to land?
Something I found on Wiki:
Birds and airplanes face into the wind when taking of or landing so they can take advantage of wind speed. If the wind were at their backs, they would not have the control they have when facing into it. But differences exist here too: While large birds need a prolonged takeoff run to become airborne, small birds can jump straight into the air on takeoff; they can generally achieve lift from zero air speed. Larger birds can fly at speeds within a minimum and maximum range, but they cannot take flight at zero air speed. Therefore, larger birds need to generate air speed before they can take off. The often run over the ground or water until they reach the minimum air speed needed to take flight.
So, were the Pelicans "running to take off", or slowing down "to land"?
M-L
The were taking off. Here is previous pic.
I’m intrigued by this. Have a look at the way those fingers at the end of the wings are open? To gather maximum speed shouldn’t they be closed? Some time ago I found a chart displaying pictures of the wings of birds during takeoff and landing. I wish I could find them again. It was fascinating. It showed the position of the wings using updraft and downdraft (if that’s the right word for it?), slow down and speed up. If anyone can find something like it, I’d love to see it.
Thanks Alan
M-L
Nice shots Alan. They are a great bird to watch, once they take off they seem to fly around with no effort.
M-L all i can say is when they take off they have to hop on the water several times to take off (as shown in the second shot) as for the wings i have no idea, but here is a link showing take off and landing pics.
http://www.squidoo.com/flying-pelicans
Shorty......Canon gear
Canberra
http://www.flickr.com/photos/rawshorty/
I'd expect that the greater the wing surface area the greater the lift to enable take off. That might explain the spread primary wing feathers in BajanAlan's photo.
On a number of occasions I've watched wedge-tailed eagles taking off & the power that goes into achieving lift from their spread wings as they slowly gather speed is awesome. That's one large bird that doesn't need a run up before taking off.
I know all that, but there are rules just like there are rules in aviation, the angle the bird holds the wings during takeoff and landing is most important. Just like on an aircraft, if you would put the flaps on the wings at the wrong angle , you would crash land, or never get off the ground. That's what I'm after. You can actually tell by looking at their wings what the birds are doing. (I was hoping someone could tell me?)
M-L
Wow, this topic has really got deep now! So, for M-L’s benefit especially, I’ll throw in my two penneth!
I’m certainly no expert on ornithology – but I do know a little bit about aeroplanes so I’ll try to cover as many of the topics there as I can.
Yes, birds and aeroplanes normally take-off as much as possible into wind to shorten the take-off run. However, that is not always the case. Obviously, if a bird takes fright near the upwind end of a lake it will sacrifice a short take-off in order to just escape. After-all, it is better to be rapidly getting away from you predator than to be heading towards him! For expedience, aircraft will sometimes take-off with a slight tailwind with the knowledge that they are going to use up more runway in doing so (and will require a lot more runway if they decide to abort the take-off and stop!) For example, depending on the model, a Boeing 767 can accept up to 10 or 15 knots of tailwind.
Fixed wing aircraft need a particular amount of air passing over their wings to generate the required amount of lift. To do that, they have to move forward faster and faster until they achieve that speed. The engines simply propel the aircraft forward and the wings simply lift it. However, a bird uses its wings as both engine AND lift.
For most large birds, I suspect that, initially, the wings are used to propel forwards (and waterbirds use their feet as paddles to assist with gaining that speed). Once fast enough to get airborne and remove the drag of ground or water it will still flap like crazy to get to full flying speed and then climb away. An aircraft does much the same. An aircraft will apply a lot of power to the engines and will leave the ground just after it gets above its stalling speed – but this speed needs a high wing angle which, in turn makes high drag. The aircraft therefore will retain the high power setting until it accelerates to a more efficient speed and can safely climb away.
M-L mentioned ‘flaps’. On an aircraft, these are used to alter the shape and size of the wing. The bigger and more rounded the top surface of a wing, the greater it’s lift at a given speed. This means that an aircraft (or bird) can take off or land at a slower speed and therefore need less ‘runway’. However, this extra lift comes at a price – extra drag. So, as soon as practical, the aircraft retracts its flaps and a bird reshapes its wing into a more streamlined profile. Incidentally, a pilot relies on sensitive instruments to warn him if he is about to go too slow for the wings to support the aircraft and ‘stall’. A bird has its own, very accurate, stall warning system – its feathers! Just as it is about to stall, the airflow over a wing separates and becomes turbulent. This actually starts to ruffle some feathers on the top of the bird’s wings and ‘tickles’ it – thus warning the bird that it is running out of airspeed!
Smaller birds are able to flap their wings more rapidly and I imagine are able to put much of the energy (engine thrust) into the vertical plane and thus climb away much more quickly and steeply. I guess we could equate a large bird to a lumbering Jumbo and a small bird to a nimble and powerful fighter-jet.
Small aeroplanes have fixed undercarriage. Their wheels are always down which makes for a very simple system. However, once again there is a penalty – that old foe, drag. It is much more efficient to be able to tuck those wheels up in the aircraft out of the slipstream. Birds do the same thing. They lift their legs and tuck them up into a beautifully streamlined position. Just before they land, aircraft lower their landing gear (dangle the Dunlops) to prevent that aweful scraping noise and early retirement. Birds do the same. The most spectacular is when one watches waterbirds gliding in with their webbed feet splayed and angled back like waterskis. This seems to have two purposes; it gives them a controlled touchdown and transition from flying to floating without digging in and flipping over (as would happen with a wheeled aircraft) and the extra drag of such large paddles very quickly reduces their landing roll.
Now, the wing-tip feathers! Looking at the photos I suspect that a Pelican’s tip feathers are spread like that naturally. However, they undoubtedly act like an aircraft’s ailerons. By changing the angle of them (up on one side and down on the other) the wings suddenly have different amounts of lift and one wing will drop while the other rises. Then, like riding a bike, the aircraft or bird will turn. Being on the end of the wings, these feathery ailerons will have the greatest leverage and, I suspect, when the individual feathers are spread slightly it will increase their effectiveness. This is best seen in large birds of pray soaring in thermals or ‘hovering’ as they watch potential prey. Just the wingtips move to control their flight. Aircraft are basically the same.
I hope this covers all of M-L’s concerns! Let me know if you disagree or have alternate theories.
Cheers!
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Thanks Roly, that was the best and easy to understand explanation I ever got.I was most interested in the function of the wing-tip feathers, and the way they are used by changing the angle.
thanks again, i loved reading it.
M-L
I thought the wing tip feathers acted to reduce turbalance and therefore reduce drag!
My 2 bits
Alan
If this was an aeroplane's wing it would be called 'anhedral' - downwards bending.
This gull was just surfing on the upward air current and looked like it was just hanging there. It was obviously close to the stalling speed. If you look at the top of its wing you can see a couple of feathers lifted up by the turbulence of pre-stall airflow - its own, inbuilt stall warning system.
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Undercarriage up - and nicely aerodynamic!
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
You could well be right, Alan!
Wing tip vortices are a huge component of drag. As the higher pressure air under the wing slips around the tip of the wing to the low pressure area on top it forms a powerful vortex - the turbulence which absorbs a lot of energy. Many modern aircraft now have winglets and these help. Only a few percent but, with the price of aviation fuel, every little helps!
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Those winglets were copied from birds.
Anhedral must mean unstable. Like those Starward vipers.
Let’s not forget the function of the tail, a bird can spread it , tilt it, shift it up or down, use it as a rudder, to change direction, or slow the bird down
M-L
Yes, essentially, dihedral (wings sloping upwards) gives greater stability due to a sort of pendulum effect. This is great until you want to turn or maneuvre - especially in a hurry! It can be TOO stable! Fighters etc actually use the instability of anhedral to increase their maneuvrability - but they are then harder to control. They therefore rely on computers to reintroduce artificial stability to enable the pilot to fly them!
Interestingly, some large aircraft (like the Russian Antonov - 124 and the US Lockheed Galaxy use anhedral wings - but they are high mounted. Luckily for the birds, they can instantly warp their wings to any shape that best suits them at the time!
Also luckily for birds, they don't have to pass any exams on the theory of flight before they take to the air! In fact, it's interesting that, after all these years, there are scientists who are now challenging the conventional theory of flight!!!!!
I think the birds have the right idea and attitude to flight theory! :)
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Bye
They are such awesome creatures, aren't they?
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Yes Roly, birds are amazing creatures. And I apologize to Alan for high jacking his post for this discussion. I think it was very interesting, and answered my question .Thanks for the great effort Roly , very much appreciated.
M-L
High jack all u want. Anything that promotes birds is cool by me.
Rolyd, thanks so much for the erudite discussion. Is it the case that the shape of an aircraft's wings promotes faster airflow over the upper wing surface which causes lower airpressure there & thereby generates lift?
Wonderful shots! Pelicans have always fascinated me - must have been all the times watching "Storm Boy" when younger
Still learning a lot about all birds, but one thing that always impressed me about Pelicans in particular, is the young apparently "listen" to the parents while still in their eggs, so they can easily identify them when hatched. Probably something a lot of other bird species, I don't know about, do too, but fascinating nevertheless.
Hi Woko, as I said I know very little about birds but I do know a bit about aircraft – or at least I thought I did, until recently!
When they taught me to fly back in 1967, that was, indeed, the theory of flight. Bernoulli’s Principle said basically that if you increase the speed of air you get a decrease in the pressure. Therefore, because of the camber, air going over the top of a wing (or through a venturi like a carburetor) would speed up and therefore drop in pressure. The relatively higher pressure air underneath would then lift the wing up.
That was easily demonstrated by holding the edge of a piece of paper horizontally in front of you and letting it droop away from you, forming a wing’s shape. If you then blow across the top, the paper will rise. Another good one for kids is to dangle a large spoon gently by the very end. Turn on a tap and get a gentle but continuous stream flowing. If you then move the spoon into the water so that the outside of the bowl just touches the stream one would think that the spoon would be deflected away – but that is not the case. The spoon will be ‘sucked’ into the stream! Gently moving back out of the stream, the spoon will pull back until it finally ‘stalls’ and comes free.
That was all quite logical, however, it didn’t account for an aircraft being able to continuously fly inverted! Something else had to be a factor. I don’t know who but someone once said, "With a big enough engine you can make a barn door fly". It certainly needs more power to fly level, inverted. Perhaps it’s just the planning effect – I now have no idea!
In recent years, some scientists have questioned the old theory of flight and I don’t think they have yet to come up with a consensus! It seems that for the past 45 years I’ve been blissfully unaware of what was actually keeping me aloft! Perhaps the birds know the real answer!
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Model Aricraft people fly Lawnmowers.
Here are some more wings for Marie Louise
Yes, Alan, I've even seen flying toilet seats - but I've never actually seen a UFO!
Those wings have such beautiful symmetry!
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Thanks Alan, I love them.
Roly, wouldn't it be great if we constructed aircraft that would flap their wings? I can just picture an A380 flapping those huge wings.
M-L
We were watching a pelican the other day (may have been at Xmas) gliding low over the water, and assuming they must get a huge amount of lift from the ground effect, as he/she was just gliding effortlessly over the water for ages at about 6-12 inches above the water.
It was pretty impressive.
Cheers
Tim
Brisbane
It has never occured to me that (the wings of) flying toilet seats have a beautiful symmerty. Next time one zoooms past me, I will pay more attention to it.
M-L
M-L
Oo, somehow two toilet seats zooomed past. Sorry.
M-L
Were the lids up or down?
Roly
Healesville
https://www.flickr.com/photos/36062443@N04/sets/72157632450588204/
Good comeback Roly
nothing is better than a good joke
M-L
Depends who is driving!
Could the wing tips be spread to allow an "easier" upward beat, ie, it lets the air through, and thus less drag on the wing, less energy, then on the power stroke, they are closed? just a thought!
To me the parrot pics show the opposite?