Only the foxes kiss goodnight

My anthropology professor is German and I've heard him use this phrase only a handful of times. He talks about the landscape and then refers it to a place where "only the foxes kiss goodnight". I tried to google it but nothing came up. Any clues on how this got to be a phrase?

It may be a phrase in German, but it is not a known English phrase.

My German wife doesn't recognise this as a German phrase. Mark you, she has lived in England for more than 50 years!

that's a rather pleasant turn of phrase - perhaps it was a localised country saying for uninhabited land.

L