Perhaps the kite sees the lens as an eye staring at it.
Trying binos as suggested by roseway seems like a worthwhile experiment.
Wow, so sorry, I completely failed to absorb Roseways suggestion of binoculars. My attentive span must be ‘getting worse’.
I have a big old fashioned pair of binoculars I can try, as well as a modern compact pair. That’ll be an interesting experiment to try, when an opportunity presents itself.
I know they’re not there now, without even looking. Because when they are there, they tend to whistle fairly continuously. Quite unmistakable, and not unpleasant.
When just one kite is present, he/she is sometimes joined by a single rook. Kite and rook perch almost shoulder to shoulder, both appearing to enjoy the ambience, until the kite takes off. At that point the rook seems to suddenly remember he doesn’t like kites and follows, squawking and pecking aggressively at the kite’s tail feathers. Kite takes no notice. One day if I’m very lucky, maybe I’ll catch a video of that.