Cuckoo not posing at all but Turtle Dove joy

On Wednesday 15th May in the afternoon I had TOIL from work and on a beautiful sunny day I was keen to photograph the showy Cuckoo at Buckingham. It wasn't at all showy for me. I arrived as soon I went to the riverbank walk as instructed it flew to a bush by the river. A binocular laden walker walking across the path 5 minutes later flushed it. Right over the river. Half an hour later it returned it was in its favoured bush, I saw it for a mili second before buried itself in the bush. Another binocular laden walker flushed over the river! Avocet around 4 seen on the scrapes and 2 Buzzards. In 3 and a half hour wait the bird returned 4X but each time was flushed by passers by (3rd time- 2 men spraying chemicals CP3/5 and CP15 on the marshes on an RSPB reserve??! and 4th time- a dog walker). Thorough dispirited I moved onto my traditional Norfolk Turtle Dove, the mood brightened considerably as I immediately heard the purring and in front of the usual built place, 2 flew up from a field and east. Meanwhile one could be heard by the built place, one heard and seen in a bare tree just west of there and one from the copse making 5 Turtle Doves in all! A great tally and hopefully it means there are thriving here and will have another successful breeding season. On Thursday 16th May, arriving at Buckingham again at an empty carpark at 7.30am I was hopeful of less disturbance. As I was setting up my kit first a dog walker arrived walked off ahead of me then a bloke on a buggy drove down the track and passed the bush in question, but he didn't flush the dog walker was ahead of me walked past the bush and the Cuckoo flew over the river and didn't return in 90 minutes!