This morning a skein of geese flew overhead when I was out walking the cat and as they were making a racket I looked, I suspect the racket they were making was because they were nearing their summer feeding grounds on Duddingston Loch near Auther's Seat in Edinburgh. Whilst I watched these geese fly over in a perfect V formation the middle bird of each leg of the V switched places in perfect synchronicity, one crossed over to the left whilst the other to the right and I wondered if there was a reason?
Geese use the air pressure generated from the wing beat of the bird in front to ease their flight. However, logically this can only apply to the inside wing of the V formation. The outside wing therefor works harder. So if two birds want to rest their outside wings by making them inside wings, they switch. This is my assumption. Edit: I am not an ornithologists, I'm an engineer.
Cannot find fault with that theory, but I wonder how the two birds communicate the need to do this manoeuvre?
The Canada Geese round here, commute from a local lake to a lagoon on an island in Poole Harbour. In the evening , they fly low in a V, and you can hear them honking to one another as they go*. Sometimes they're so close to the water (ground effect?), they have to 'pop up' to fly over a moored boat. *"Red 1, this is Red leader, move positions now..."???
The wing tips generate a vortex as the birds fly. The following birds use the reduced air pressure, in the vortex, to cut drag, also the upwash, in the vortex, can increase lift for the follower.
I would have thought the answer was obvious. Glenda the goose: Hey George you won't believe what i can see. George the goose: What. Glenda: There's a guy down there walking a cat. George: No there isn't, you're just imagining things, we've been flying for a ages and you've become delusional. Glenda: I'm not, I'm telling you there's a guy walking a cat, look over there. George: I can't I've got Gloriana's backside in my face. Glenda: swap places. George: OK......OMG you're right there's a guy down there walking a cat. Glenda : told you so. George: That's sooo cute.
Don't be silly because George would still have a backside in his face after changing positions with Glenda. Unless of course Glenda was lead goose. Now there's a thought.
Yea but the backside in the face changed from the left to the right side, or visa versa, of the face, I've put a lot of thought into this.
I bow to your obvious superior knowledge on the flight patterns of our summering wild fowl. It is always good to have an experts input.
Stephen Hawking has taken a hit in my respect for him as he lists Nicola Sturgeon as one of the five most powerful women in the UK, what this will have done to here already over inflated ego is anyone's guess.