Ciconia nigra
Similar to White Stork (Ciconia ciconia), but with dark brown, metallic neck, head, breast and back. Only belly and innermost, under wing coverts are white. Legs, eye-ring and bill deep red. Flies with neck extended like White Stork, but contrasting white belly is visible at great distance. Immature birds duller brown than adults, with grey-green bill and legs.
Thin, disyllabic "ahhh-li" heard at nest and when courting. One syllable sounds like gasping intake of air, the other is a thin, piping sound. A bit like a cheap, manual, air-mattress pump. Bill-clattering used by juveniles in alarm.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology