Last summer I saw this bird in the countryside of Bulgaria (Dobrich area) and I think this is a specimen of Great Grey Shrike (
By looking more in detail the distribution of that bird (I checked in few books including the Collins Bird Guide in French edition), I noticed it is present in Bulgaria but only in winter season. However I took this pictures in August 2017.
First, is it really a specimen of Lanius excubitor?
And if yes, should it be reported in some way?
I know some other countries have reporting tool on Internet but I have no clue about observations in Bulgaria.