Where does “reiger” come from?

reiger (Middle Dutch) comes from Old Dutch heigero, from Frankish hraigrō, from Proto-Germanic hraigrô, from Proto-Indo-European (s)kreik-.

Ancestry of “reiger”, step by step

Step	Language	Word	Meaning
1	Old Dutch	heigero	—
2	Frankish	hraigrō	heron
3	Proto-Germanic	hraigrô	heron
4	Proto-Indo-European	(s)kreik-	—

reiger — Etymology, Origin & Word History | Etymology Explorer