Is "pidgeon" a correct spelling for the grayish fowl scientifically known as Columba livia domestica? Pigeon appears to be the more common spelling, but it looks strange to me.
For comparison, words such as bludgeon, bridge, and midget use the "dg" construct, and words like belligerent and indigenous do not. I supply the following Ngram to save time for anyone who may need to refer to it.
Additionally, can one predict which way a word with the "idge" sound will be spelled, or is this a case-by-case kind of thing?