The strong wind was hitting a dense hedgerow which must have deflected it upwards. A flock of rooks was playing in the up-draft. One by one the birds swooped in, were flung skywards and performed intricate aerial manoeuvres, loops and rolls and stalls, before levelling out and joining the queue to do the whole thing again.
Some people might say that describing this as ‘play’ is to commit the sin of anthropomorphism. They would claim that a mere bird is incapable of something as sophisticated as playing. I don’t agree. I watched that flock carefully and I could deduce no practical reason for what they were doing. Some observers might claim that they were honing their flying skills to help them escape from peregrine falcons, but I don’t think this is what it was about. It was just for fun.
Rooks are members of the crow family and research has shown that many members of this family are far more intelligent than we realised. Tests on tame rooks in captivity have come up with the remarkable conclusion that they are on a par with chimpanzees when it comes to solving problems and making and using tools.
Another reason why I think they were playing is I believe this roaming flock was composed mainly of young birds, probably accompanied by a sprinkling of un-mated birds that were a little older. Youthful exuberance is a strong motive for play.
Ravens are closely related to rooks and an observer in Scandinavia watched, and I think videoed, a small group of ravens on top of a tall snow drift. The birds took it in turns to flip over on their backs and toboggan down the slope. What motive could you ascribe to that odd piece of behaviour other than the fact that they were playing?
Rooks are quite widely distributed in northern Europe and there is a closely related sub-species in Asia. But it appears there are more of them in Ireland than anywhere else of comparable size in the world. The landscape of this country suits them and they are probably our commonest breeding bird. They have increased in numbers in recent years, partly because many of them have learned to exploit the micro-climates and feeding opportunities of urban areas, particularly in winter. Winter flocks often have jackdaws mixed in with them and we know from historical records that jackdaws have enjoyed the comforts of towns and cities for centuries. Rooks have learned this much more recently and it seems likely it was the jackdaws who taught them.
The fact that rooks are so common and so ubiquitous means that we tend to take them for granted. We shouldn’t — they are absolutely fascinating birds.