single great spotted woodpecker on tree trunk with hollow in kampinos forest in mazovia region of poland

single great spotted woodpecker dendrocopos major dzieciol duzy tree trunk hollow hole juvenile nestling kampinos izabelin puszcza climb feed parent care conservation national park forest wood bark bird greenery foliage reserve avian wildlife nature natural life ecology fauna poland europe wing beak nest red color wild zoology travel outdoor one black latin nestlings spring mating season mazovia region