Gannets and Drift

Ships_Cat

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Am on the boat in the marina and yesterday afternoon 5 gannets dived into the aisle just along a bit from us. They came up together and flew quite low along the aisle behind us with an about 17-20 knot crosswind - the thing that I hadn't noticed before is that they flew along angled into the wind in the same way as one sees when a plane lands in a cross wind.

I guess that I have seen this before but just assumed that the bird was pointed to where it wanted to go and the wind was just getting the better of it and blowing it sideways - but in this case they clearly wanted to fly lowish down the aisle between the boats and masts but they were actually facing 20 or so degrees off to compensate for drift.

They must have some inbuilt sense where they keep track of relative bearing to their destination as they fly along and compensate for drift. I wonder if others have noticed this before?

That aside, a few minutes ago there was an almighty bang as if something big had hit our mast or rigging. Wife and I just about jumped out of our skins. But standing on our upturned dinghy was a very dazed looking gannet which I could walk right up to. But by the time I checked to see if it was in one piece then got my camera it had recovered and flew off - can only think that it was so busy looking for fish that it had flown straight into our rigging /forums/images/graemlins/crazy.gif. Again, a first - have never had a seabird collide full on with the boat before.

John
 
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Again, a first - have never had a seabird collide full on with the boat before.



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I have seen seagulls whack into the bridge on ships, always worth a good giggle /forums/images/graemlins/grin.gif That's what they get for tryin' fancy aerobatics!
 
Aircraft on approach to landing broadly have two options for countering a crosswind. One option is to simply turn your nose a few degrees into the wind using (mostly) rudder so you progress slightly 'crabwise' on your intended course. The advantage is that you stay flat but the disadvantage is that just before you touch down you have to kick back to flying straight again otherwise you put a slight tranverse load on the landing gear as you touch down going slightly sideways.

Option 2 eliminates that problem because you maintain the same direction but use aelerons to slighty dip the wing that is pointing into the widn so that you sideslip into the wind to counter the effect. The result is that as you touch down you are facing nicely straight but potentially your wing tip is at risk of striking the ground as you touch down one wheel at a time. Hence this technique also requires a final correction just before touchdown.

Going back to your gannets, from recollection I think that they seem to use a technique that combines both these options but they are constantly ajdusting it. A bit like asking a child how it manages to run - it couldn't begin to explain how it can do it - it just can!
 
Hi Rob

My experience of a seabird flying into the boat reminded me of a case where a birdwatcher flew straight into a boat.

We are off home in a short while and no gannets around at moment but next time I will see if they are flying wings dipped into the wind as you describe they might. Only birds at moment are Black Backed gulls and with the wind averaging around 20 knots and gusting to 30 they, of course, don't tend to get into flappy mode and are just spending all their time gliding.

John
 
Bird behaviour

Nothing to do with gannets, but I saw a fairly spectacular bit of bird behaviour yesterday (Sun).

I was on the helm enjoying the sunshine in the West Kyle (Bute) when a birdy racket stirred me out of a dwam. A tern was being engaged in an airborne dogfight by a herring gull approx. twice its size. The flying display was only outdone by the cries of the tern. The gull kept at it for a good ten minutes without tiring... it was either trying to get the smaller bird to disgorge its dinner or it was just being nasty. Either way it was harrying the tern with no intention of letting it go.
After watching the tern ducking and diving, narrowly escaping being bounced by the gull I noticed first one then three other terns joining in.
It was clear that while the gull was still after the original tern the other three were the cavalry come to the rescue.
They were mobbing the gull which eventually gave up the chase.
I am sure if they hadn't turned up their mate would have been clobbered or driven to exhaustion.
Better than telly.
 
Brilliant fliers (mostly) and very handsome. I saw one very close to on the way back from Alderney at the end of July. It was sitting on the water, mid-channel, and didn't fly away even though we passed about ten feet from it. I grabbed the binos and saw that it was caught in a piece of discarded fishing net. It couldn't fly and was able to paddle with only one foot. We turned back and after circling it for what seemed like ages, my son was able to hook the net with the boat hook. Once pulled on board, I was able to cut the net away with scissors whilst the ungrateful bird pecked me for all it was worth. I guess it had dived for a fish and had gone straight through the floating net, which was green and probably was pretty much invisible.

That piece of net is now in the recycling bin. We saw quite a few pieces of net, seemingly all about a foot or so square, on that trip.

Also, thanks to the yacht that came to see if we were OK after we'd been turning in tight circles for some minutes when we were trying to catch the bird. Very kind and most gratifying. /forums/images/graemlins/smile.gif
 
I was out on a routine coastguard job last year when we found a not-well gannet in a field en route (this is in East Kent, not your regular gannet country). We captured it inside a regulation hi-vis CG jacket, and took it in the truck to the nearest vet. It did get a bit cross but we managed to keep its awesome beak under control. Happy to say it recovered and was released a few days later. Beautiful bird.
 
They do have awesome beaks don't they. The one who crash landed was so busy working out what the hell had happened to it that I could stand beside it but unlike other gulls the beak put me off actually touching it to see if it was injured. Also, they are quite big birds.

I have mentioned this previously but we have cockpit lockers across the inside of our transom and some months back I was head down in one of those painting when there was a massive splash immediately behind the boat. I got up and peered over to see what it was just as this great gannet came flapping up behind the transom in my face - we both got one hell of a fright.

John
 
Re: Bird behaviour

We have some plucky little swallows at Toward Point. Yesterday I watched a gang of them harassing a kestrel, they took it in turns to dive bomb it. Previously I have seen them ganging up on a magpie.

Really love watching gannets though, especially against a gray sky

Cameron
 
It makes you wonder why we bother with all those complicated calculations when setting a course to steer to counteract the effects of tidal stream and leeway and then probably getting it wrong
 
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