In broiling sun or icy winter gales, often drenched to the skin by squalls, Mike Tomkies has for many years negotiated the slippery, almost sheer rockfaces in pursuit of an understanding of his favourite bird, the golden eagle. From damp, cramped hides on precarious cliff faces in remote Highland mountains, he has kept watch for up to 38 hours at a time to record the remarkable rapport between the parent birds, with their seven-feet wingspan and the incomparable joy of watching them teach a youngster to catch prey. Although covering the nesting success of ten eyries, On Wing and Wild Water concentrates mainly on two magnificent pairs of eagles, one of which almost brings about Tomkies' death as he struggles under the weight of film equipment to the farthest neck at the end of what he calls the 'killer trek'. The eagle treks are accompanied by an extraordinary vigil when a pair of even rarer black-throated divers nest on an islet on the loch and some peregrine falcons colonise a nearby sea cliff. The book is laced with all the ambiguities of a taxing wilderness life without gas, electricity, telephone, TV or postal service and ends with a memorable trek to a pair of golden eagles nesting in the Lake District after a century of extinction south of the border.