A canopy of trees extends over the lane leading to the church, and this morning a chattering noise could be heard emanating from the leaves overhead.

Even the dog looked up to see what was causing the rumpus. With great speed and agility, two grey squirrels appeared, chasing through the tree tops and sure-footedly racing along the branches.

Every now and then they would stop stock-still, as if to see who would capitulate first.

Grey squirrels are an argumentative species and indulge in chases, threatening displays and other behaviour through which they maintain a hierarchy of dominance. The dominant animals threaten their victims with harsh, repetitive, chattering noises - 'chuck-chuck-charee' - accompanied by a rhythmic tail flicking and foot stamping, and they will bite the tails of the more submissive individuals as they pursue them.

Their high-speed chases make full use of the space - across the ground, up and down the trees, even leaping from one tree to another. They are extremely agile climbers and jumpers in their natural surroundings, and very fast - on the ground they can run at speeds up to 18 mph.

They can jump to a vertical trunk where they cling effortlessly, and they avoid detection simply by moving to the far side of the trunk. They can also swim.

But this morning's pair may not have been negotiating status since grey squirrels engage in similar chases during the breeding season, with males pursuing fertile females.

Mature females can produce two litters a year, usually in early spring (January to March) and summer (May to July), giving birth in untidy nests or dreys made of twigs and leaves.

The territory around the drey is defended against intrusion from other squirrels, but the male takes no part in raising the young.

Grey squirrels are not native to Britain.

They were introduced to around 30 sites in England and Wales over the period 1892-1920, and spread rapidly during the 1920s.

Their relations with humans are varied.

They are a serious pest of forestry, but many consider them an attractive asset to towns and parkland.

Certainly, their aerial antics provided an engaging spectacle on a morning walk.