Question

Apologies for the poor pictures, they are a crop of a tiny part of a picture taken with max zoom. A nature reserve in Bulgaria, I often see those birds while I hike there. They let people come quite close, but they always care to stay between your eyes and the sun. Only this time I managed to see their back in full daylight, but it happened because they were very far. I searched some information online and I understood that the most commons birds of prey in the area are theKestreland theBuzzard, I think the one in the pictures is a Kestrel. But when I tried to search online to confirm the identification I could not find a picture of the back, it seems I am not the only one who can only see them against the sun. Well, it does have the characteristic pointy wings of a falcon, so that narrows the choices. I wouldn't worry about the back - most birds have a fair amount of variability in plumage as it is, and with young birds flying around this time of year, that adds to the fun. I'd focus on the tail, which is likely to be far more useful.

That black band at the end of the tail seems to be a good fieldmark for Kestrel, but I'm not sure about the white border. Perhaps it's a young bird and the white border will wear off (as so often happens with young birds' plumage). Or perhaps it's simply an artifact of the photograph/enlargement process. Edited To Add:
In the attached links, the various illustrations show both the black terminal band and the white border to that band, as well as the brownish back as we can see from your photo. I'd lean toward the Eurasian Kestrel rather than Least Kestrel, but I'm not experienced with European birds, so you might want to take that for what it's worth.

Answer 1

The bird in question is likely a Eurasian Kestrel, identifiable by its pointed wings, tail pattern with a black band, and possibly a white border, along with its diurnal hunting behavior and strong vision.

Step-by-step explanation:

Identifying birds of prey such as the kestrel and the buzzard in Bulgaria's nature reserves involves examining fieldmark characteristics including wing shape, tail patterns, and plumage. The kestrel, part of the falcon family, is known for its pointy wings and distinctive black band at the end of its tail, which may or may not have a white border. This white border can be indicative of a younger bird whose plumage will change as it matures.

Birds of prey are active during the day (diurnal) with sharp, hooked beaks, strong legs, clawed feet, and excellent vision, all adaptations for hunting. Variation in plumage can be influenced by age, habitat, and lighting conditions, which may affect how colors and patterns are perceived in photographs.

When attempting to identify a bird of prey, observers should note its behavior, habitat, and any unique fieldmarks such as the tail and wing patterns, which are more consistently reliable than coloration affected by lighting or the bird's age. The presence of a black band and a brownish back, as seen in the inquirer's photograph, suggests the bird is likely a Eurasian Kestrel.