This is why you visit olive groves in Greece. Olive Tree Warbler
I'm sure that I'm not unique in having difficulty associating familiar birds with completely out of context habitats. I remember, in 1993, finding myself questioning the id of Tree Sparrows, migrating along the cliff-top at St. Margaret's Bay, because my only experiences were from the Hertfordshire countryside and the Ashridge Estate. They were simply not on my radar as a coastal migrant, thus my brain refused to recognise a call, of which I was completely familiar, because of the habitat they were encountered. Over the years, Greek olive groves have provided me with some exceptional birding experiences and I've enjoyed, immensely, the testing conditions of cloudless blue skies and the dappled mix of light and shade created by the foliage of these trees. Prior to 2011, and my rediscovery of specimen hunting, I'd have nailed the id of this bird on the day, using the back of the camera to assist my efforts.
So what have I got to go on? The above image is the best I managed when I initially found the bird. Obviously hindered by the dense vegetation, the pale tipped primaries, leg colour and that very strong supercilium might be of assistance? This individual was never settled, moving steadily through the foliage searching for food, certainly not overly worried about my presence.
I managed a series of twelve images in total before it was lost from view. The two images above allow an appreciation of the rusty tone to the brown plumage and a better view of the long primary projection, in the top image, and the substantial beak proportions, in the lower one.
So there you have it. My mystery bird is nothing more exciting than a Great Reed Warbler. I've seen loads during my holiday travels, even a few in the UK, yet didn't think of it when I was actually standing in that olive grove, nor when initially looking at the photos again today. Why? A mental block, my brain incapable of spotting the obvious, purely because of the habitat. I must say that I've rather enjoyed this little exercise and might see what else I can find tucked away in the hard drive, awaiting a second look?