Why seagulls decided to take over the city of Bath

The other day, I was walking through the centre of Bath, deep in thought (probably wondering whether I would still be alive when the new spa centre finally opened), when I was startled by a tremendous hooting from a lorry just behind me.

The other day, I was walking through the centre of Bath, deep in thought (probably wondering whether I would still be alive when the new spa centre finally opened), when I was startled by a tremendous hooting from a lorry just behind me.

I turned round.

Everyone turned round.

We all love a traffic altercation, don't we?

But this was one with a difference. It wasn't man vs man. It was man vs nature. The lorry-driver making all the noise was hooting at a bird in the road. It was a large seagull, walking very slowly in front of the lorry. Not a white seagull, but a brown spotty seagull and therefore a young seagull who didn't know the rule of the road. The rule of the road for seagulls is: get on to the bloody pavement, and leave the road to lorries. But the young seagull had the courage born of ignorance, and strolled on down the middle of the road. Someone leant down to pick it up. The seagull gave him a powerful peck with its cruel hooked beak. Someone retreated...

The young seagull finally got bored with the road and got on to the pavement and started walking down New Bond Street, at which point I gave up following it, though I suppose I should have gone on, if only to see the faces of the people coming the other way.

("Did you see who just walked the other way?"

"No - who?"

"A seagull!"

"Have you been drinking again, Deirdre?")

Actually, the idea that anyone in Bath would be surprised at coming face to beak with a seagull is far-fetched. Bath was invaded and taken over by seagulls years ago. You can hear them all the time, and see them flitting around above you, and walk in the results of their presence, and you can buy the Bath Chronicle and read the pros and cons of a campaign for gull-culling.

Actually, we still remember a time when the sound of seagulls was a maritime sound, so, deep down, we think they might all still push off back to the seaside, but a Radio 4 programme all about seagulls that I heard the other day soon cured me of that illusion. (Have you noticed that, sooner or later, there is a Radio 4 programme about everything? If we remembered everything we learnt on Radio 4, we would hardly need an education system.)

It is not, as I had always thought, a matter of the herrings running out, or the fish moving away, or anything to do with the sea at all. To explain the inland movement of herring gulls and lesser black-backed gulls, the seagull expert unhesitatingly pointed his finger at the Clean Air Act of the late 1950s.

"This made it illegal to burn rubbish on municipal refuse tips," he said. "The idea instead was to cover up the refuse with earth, but the gulls were too quick and got there first."

So, the gulls discovered a ready supply of food that gave them all the fat and sugar they needed, and they moved into cities - Bristol, Bath, Gloucester, etc. Cities, moreover, that provided a habitat very like the cliffs they had just vacated, so, instead of building their nests in precarious crannies that no predator could get at, they built them in mansion-top and high office crannies that were similarly free from predation.

I myself was privileged to glimpse the world of gulls not long ago. I went to a piano recital at the Bath Guildhall during the recent festival, and as there was nothing in the room worth looking at, or at least nothing to match the music, I spent most of the time staring out at the sunny roofs beyond - the dome of the covered market first, then a whole succession of Georgian rooftops.

It seemed at first very tranquil. There was blue sky in the distance, and the occasional far-off plane, and no other sign of motion. Unless, I suddenly realised, you counted the seagulls. They were everywhere. Gulls preening. Gulls flirting. Gulls arguing. Gulls scrabbling for a chimney top. Gulls practising flying. Gulls practising sleeping...

It was gullworld up there, like a non-stop avian TV soap, and there was no sign of any human activity whatsoever. As far as the seagulls were concerned, Bath was their city, and all the traffic and shopping and business far below, at street level, was of no more concern to them than the fish in the sea are to a cross-Channel ferry. For a moment, I saw things from a gull's point of view.

And I realise now why that young seagull in the roadway, in the midst of all the traffic, had a look of denial in his eyes. He simply couldn't accept that we earth-dwellers had any part in his city, and couldn't wait for us to get out and go back to wherever it was that we had come from.