There is a line of trees on either side of the road driving down to our house that have grown over the road and created a canopy that is pretty dense. Tom, our grandson, calls it the “tree tunnel”, which is pretty accurate. I was driving down it the other day when I saw a large bird flying fast ahead of me, quite low to the ground. Initially I thought it was a wood pigeon but quickly realised it was a sparrowhawk, out on the hunt.

Sparrowhawks are much commoner now then when I was a boy, and numbers have bounced back due to conservation success. Although one of the smaller birds of prey, they are handsome with bright yellow feet and eyes and a barred breast. The hunting technique is quite spectacular, flying fast and aggressively between trees and bushes looking for small birds. I remember seeing a bunch of sparrows crouched nervously in the depths of a hawthorn bush whilst a sparrowhawk circled it like a Spitfire. This one was flying fast down the trees before taking a hard right into a bush, but emerging empty-handed, or empty-taloned.

They have a very varied diet with reputedly up to 120 bird species on the list, including bigger victims such as magpies and woodpeckers. Lovely to see, although they can ravage small bird populations if they latch onto a garden feeder, if they get the chance.

However, thinking about bird numbers, I reflected on a piece of info this week which was ideal for one of Rog the Oil’s famous pub quizzes - I saw a question as to what is the world’s commonest bird? I confess I was trying to think of widespread birds like gulls or sparrows and but the answer is obvious (if you know) - chickens, numbering over 30-billion, which is staggering. I’ll test Rog next week and try and bet a pint with him!

• Fred Knobbit is a nature blogger. He grew up in the Pennines in Lancashire on the edge of an industrial town but is now safely in Cornwall. You can read his archive at www.bodminblogger.com