When the wind blows
One way or another, it has been a pretty windy summer.
That has at least ensured that there has almost always been plenty of movement on the loch, especially last weekend when white horses were galloping across the restless waters.
One of the benefits brought by the wind and waves has been the absence of deadly algae clogging up those waters.
Last weekend provided rare entertainment for those who enjoy watching birds, albeit that the strong wind ensured that some birds were made to work that bit harder for their suppers.
There were those, however, which showed a real appetite for using that same wind as a vehicle for fun. Ravens, rooks and crows are superb aviators and when they get the wind under their tails they produce some really breathtaking displays.
Carrion crows usually perform in pairs or family groups.
Ravens are very capable of performing some amazing aerobatics, also often in family groups, corkscrewing through the air, flying upside-down and showing a real talent for some amazing aerial stunts.
Rooks are entirely different. They often come together in great swarms to hurtle across the sky in what may seem to be confused disorder. In reality these gatherings might instead be described as ordered chaos.
Their mass game-playing – resembling tag and catch as catch can – may include conducting headlong, seemingly suicidal dives, ending with dramatic, superbly timed recoveries and pivots. Suddenly the sky is full of dancing dervish rooks.
I always think much the same of gulls. All of us, I’m sure, will have marvelled at the sight of gulls zooming nonchalantly among and amazingly close to the foaming, pounding waves of our seas on the wildest of days, literally dodging the advancing rollers. They skim so close to the churning, boiling water that they seem to be in danger of being swallowed up and swamped by it but they never seem to put a foot, or rather a wing, wrong.
As there does not seem to be any practical reason for them to challenge the conditions so, one is forced to conclude that they are performing these daring flights simply for fun.
However, the heron I watched battling with the wind last weekend certainly did not have fun on its mind. It rose from the lochside calmly enough but once it had cleared the shelter provided by the trees it found itself unmercifully tossed to and fro like a piece of flotsam, finding progress more than a little difficult.
Herons are remarkably strong flyers, due to having an extremely large wing surface in relation to an extraordinarily light body. When hawking was literally the sport of kings herons were regarded very highly for being excellent quarries for the hawks. Herons are capable of gaining height very quickly, thus providing excellent sport for the hawkers’ peregrines which usually try to come at their prey from above.
But when the wind blows with such force some birds of prey find it difficult to employ their normal hunting tactics. For instance, kestrels find hovering a very tricky proposition in these conditions.
I have in the past compared the hovering of a kestrel with the computer-driven flight of a modern airliner. If you are in a window seat on such a flight you may be able to watch the wing flaps of your aeroplane and you will notice that they are constantly yet subtly moving up and down. This movement is in response to the on-board computer systems, which are constantly making those minute adjustments to maintain its equilibrium.
In a sense the kestrel’s brain is performing the same task. If you are able to watch closely a hovering kestrel you will soon become aware of similar responses in the wings and tail of the bird, always making those precise adjustments in response to the conditions. In fact I am sure that every sinew and every muscle of a kestrel seen this week, struggling to retain its position in the wind, was responding to the virtual computer that is the bird’s brain. The result was poetry in motion.
The key for the hovering kestrel is that the head must be kept as still as possible as it scans the ground below in detail for the movement of the its prey.
Kestrels depend on small mammals such as voles and mice as their main source of food.
Their eyesight is thus much better than our own but it needs to be for they have to seek out those minuscule creatures far below, well hidden by the vegetation. Voles make little runs through the grass which they use regularly. They are like little covered walkways and that makes them less conspicuous. The kestrel’s eyesight has to be sharp enough to see through that cover.
There is a special place in my heart for kestrels for when I was but a lad in short pants I used regularly to lie on my back in my special field, watching larks soaring but, more dynamically perhaps, having a worm’s eye view of hunting kestrels hovering.
Is there a more magnificent sight in nature than this? I remain convinced there isn’t.
And when the wind blows their command of that hover is even more amazing, simply gyroscopic.