Eurasian collared doves, or as we Norwegians call them, Turkish doves

Yesss thank you! They're so elegant with their little half collar!

Ringeltauben are a different species, and they're the same size as city pigeons, only fatter

Oh oops you see I'm not the expert here haha

Apparently we call them Türkentauben as well

That makes more sense, the English name for ringeltauben would be common wood pigeon

Yes, that's the scientific name for these birds, which is from the Ancient Greek streptos meaning "collar" and peleia meaning "dove"; the specific epithet is Latin for "eighteen".
The number comes from a Greek myth. A maid was unhappy that she was only paid 18 pieces a year and begged the gods to let the world know how little she was rewarded by her mistress. Thereupon Zeus created this dove that has called out "Deca-octo" ever since