Saturday, 10 July 2010

Fascinating Gull Behaviour

Living in the centre of the town provides ample opportunity to watch the behaviour of Herring gulls, especially since I have a house and garage with flat roofs ! Each year I have nests on both and can view the garage and adjoining neighbours one also with ease. This year the neighbours one has produced 3 chicks, my own house 3, but nothing from the garage. All started nesting around the same time so I knew something was up with the garage nest since the gull was sitting for months with nothing to show. I had the occasion to climb up on the adjacent wall to put a young gull back on my roof earlier this week, so decided to see what was the matter with the garage nest. It had 3 eggs in and I lifted them all and found that one had a piece of shell missing underneath - it had contaminated the other two so I removed them all because I couldn't stand watching the poor mother sitting week after week trying to hatch them ! They did dive bomb me while I was doing this and I wondered if that would be the end for this year.

They did not abandon their nest site and hung around, departing sometimes for part of the day but always returning and laying claim to their site. Even as I type this, I can look out after midnight and see them standing close to the nest. A couple of days ago they started shaking and nodding their heads beside the nest, this is the usual prelude to nest building and mating so I reckon they will have another go - late as it is.

The nest is only a couple of feet away from the adjoining neighbours roof and the other gulls territory. There is a constant reinforcing of boundaries which must not be crossed ! The gulls face up to each other and draw lines with their beaks, tapping the spot which must not be crossed, sometimes they spend hours at this.

Yesterday was fascinating, as I watched my garage gull land with a young dead bird in it's beak - probably a blackbird or starling. It shook it violently and pulled feathers and skin from it but strangely did not eat any of it. Taking it towards the nest it again shook and bashed it, all in full view of the adjoining gull and 3 chicks ! Shaking and throwing the dead carcase towards the boundary it then flew and pounced on it snatching and throwing it again, the sort of thing you would expect a cat to do with a mouse ! It then became apparent to me that this was a show of power and strength, and a WARNING to the gull with 3 chicks that this would be their fate should they cross the boundary ! It made perfect sense really, if the garage gulls lay another clutch they will be at great risk from the surrounding gulls and young chicks - which will be ready and old enough to eat anything they come across.

Later in the afternoon I saw what I took to be the Male garage gull land beside the nest with a plant for the female, seeking her approval and trying to prompt her into getting in the mood. she turned away (as females do ) and he walked away with the garland until she turned around and then he walked back, she turned away again (typical female), so he again walked away ! This time she turned around and walked after him and he came back until she nodded her approval and gave a submissive peep. The dead bird was still laying on the boundary untouched close to the nest- the male gull was showing what a good provider and protector he was with both food and nesting material, and boundary protector to boot .
Taking the time to watch and understand bird behaviour is truly fascinating !

Enjoy the pics and short vid clip with the garland.

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