Naked Science Forum
General Science => Question of the Week => Topic started by: thedoc on 21/01/2010 08:10:25
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Hi, Naked Scientists. I'm Jan from Norwich and I'm the Captain of a large oil tanker. I have a question about pigeons. We often get flocks of wild amazing pigeons land on our decks and they just stay for weeks until the crew fatten them up for the pot that is. My question is this: Does the steel in the structure of the ship which is about 50,000 tons affect the pigeons’ navigation system? I've heard that they rely, in parts, on the earth’s magnetic field.
Asked by Captain Jan, Norwich
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We'll have the answer for you on the 24th January Naked Scientists Show. Until then, what do you think? We'll include our favourite answers in the show...
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Surely the effect of a metal ship, relative to the magnitude of the Earth, would be (scuse the pun) a drop in the ocean as far as the magnetic field goes?
Presumably the birds quite like the safe (relatively) warm resting place and (apparently) friendly crew and so they stay.
Chris
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If I remember correctly, birds do have some sort of built in compass, or at least some do, so it's possible a large amount of steel could confuse them. In particular, I think this would apply to swallows who have been swallowing too many magnets at a time.
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Surely the effect of a metal ship, relative to the magnitude of the Earth, would be (scuse the pun) a drop in the ocean as far as the magnetic field goes?
Presumably the birds quite like the safe (relatively) warm resting place and (apparently) friendly crew and so they stay.
Chris
I would agree with both your points.
If these birds are coming aboard while the ship is in dock, or not far off the coast, and finding something worth staying on board for (perhaps cook throws a few titbit's for the purpose, to give him a supply of fresh meat later on the voyage), they might be reluctant to leave when, upon taking off, land is no longer in sight.
I believe birds were used for the purpose of leading ships to land, in far off days. Birds would be released and if they returned to the ship, land was not in sight, but if they flew off, the captain had only to follow them to reach land.
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would following a ship have any effect reduced wind resistance, the opertunity to have a rest in t he middle of the sea, a snake left over by the crew, it makes sence to follow the ship... if its going in your direction
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Sensors that determine the orientation of the drill string when drilling directional wells must be set in a non-magnetic length of pipe to avoid magnetic interference. This would be of the order of ten metres above and below the sensor. The Earth's magnetic field is not strong.
So by comparison I would expect that the sensing mechanism of pigeon would be upset by a 50,000 ton tanker. On the other hand some birds - perhaps pigeons - also use stars for navigation and they can certainly use the sun during the day, so they ought to be able to fall back on these alternatives.
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