I am blessed to live in Oxfordshire, when it comes to Red Kites. They are plentiful and quite reliable if you set out to photograph them. The biggest challenge is to find a spot of blue sky for your background, as a typical English white featureless sky will 'bleed' into the head and neck feathers resulting in a wash-out.
Right now [April] the Kites are flying around our skies in pairs and the occasional trio [usually a second male, hoping to move in on the female after a squabble]. Today in Abingdon, there were two groups of Kites. Each group consisted of three pairs. Amazing to watch them using the thermals to glide around the countryside.
Below are some images of my local raptors.
Taken this evening, April 4th 2017. Abingdon, Oxfordshire. 500mm f4 ISO.400 1/1250sec
This Red Kite was very low and I cropped both wing tips using the 500mm lens, but great to see a sharp close-up of the face. Look at that eye ! 500mm f4 ISO400 1/1250sec
Classic Red Kite in flight, unusually against a blue sky. 500mm f4 ISO400 1/1600sec