It is more than twenty years since a parish outing took a coachload of us from the Northern Ireland port town of Larne to spend a day at the Butlin’s holiday park at Ayr in Scotland. The day was one filled with excitement for our younger members, but there was something in the day for everyone, even grumpy men who did not like such places.

The afternoon’s programme of entertainment included a falconry display. Various birds of prey were put through their paces. Along with the swift flyers that swooped from the sky to take bait from the falconer, there was a sedate tawny owl that glided slowly along the shoreline.

The calmness of the falconer was suddenly disturbed and he began to call the owl back. The owl seemed unwittingly to have flown over an area of dunes where gulls were nesting and a flock of gulls had gathered and begun repeated dives to within inches of the owl. The falconer explained that if the owl had not been recalled from the nesting area the gulls would have begun to make contact with the owl, pushing it downward toward the sea until it came to the surface of the water, where it would have been swamped and would have drowned.

It was the first time I had seen the capacity of gulls to protect themselves through collective action.

The River Severn ceases to be tidal at Maisemore, some twenty miles south of Worcester, but a colony of gulls has become firmly established in the city of Worcester.

Vocal and forceful, they move in gangs. The spotting of food that might be scavenged brings calls to their companions to share in the spoils. Waste left outside of business premises will bring aggressive gulls within minutes. Black plastic bags will be torn apart, sandwich wrappers opened, leftovers gulped down.

The most conspicuous example of the gulls ability to organize themselves comes when a buzzard appears. The buzzard seems not to be able to learn that it is going to lose in every confrontation with the maritime invaders.

At every sighting of the buzzard, an alarm call goes out among the gulls and they take to the air, noisily mobbing the buzzard which they drive away from their nesting area through repeatedly swooping at the solitary bird of prey. There seems a look of satisfaction when they return to their perches on the roof of an industrial building.

If anyone wanted evidence of evolution by adaptation, the gulls are a loud and brash example.