Photo hunting in Bucharest's gardens

The Great Tit is a distinctive bird, with a black head and neck, prominent white cheeks, olive upper parts and yellow underparts, with some variation amongst the numerous subspecies.
It is predominantly insectivorous in the summer, but will consume a wider range of food items in the winter months, as Wikipedia says.

I've tried that and got some nice results. The birds became very friendly if you have some food for them during the winter.