I have been experimenting by linking the lens of my digital camera to my binoculars with the aid of a section of cardboard tube. The result, seen above, shows that I have had limited success, but it is a recognisable picture of a female kestrel (? kestrelle), perched in the nest-box that I put up for the stock doves that frequent the ash tree. (Incidentally, the little owls that I hoped would settle in another box have disappeared.) I think Kestrelle's visits are motivated more by mouse-hunting than house-hunting. She perches on the lip of the box, apparently doing little more than preen but she is keeping a close watch on the ground below. I can see her bobbing her head or nodding from side to side as she looks down. This helps her to judge the range of possible prey very accurately by giving views from slightly different angles. On occasion, I have seen Kestrelle spend hours in the nest-box. She seems to lead the easy, relaxed life adopted by many hunters – cats being the perfect example. The strategy is to lie in wait until a victim presents itself and, after feasting, relax even more completely. This is fine provided there is plenty of prey. When times are difficult, perhaps with a family to feed, we are more likely to see kestrels 'wind-hovering' over open spaces. This is quite easy if there is a stiff breeze to provide lift but the kestrel has to flap furiously in still air. Wind hovering would be wildly uneconomical (using up as much as half the day's energy budget) except that it gives the kestrel the ability to hunt over open ground and enhance its hunting success.
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