This was a very interesting read, thanks for sharing it with us. As an italian, however, I've to say that wolf-calls here are definitely perceived as very rude and as a thing of the past.
It’s not clearly defined, but it goes from: narrowly, the howling that Tex Avery’s wolf character does when he sees an attractive female to, more generally any equivalent reaction: whistling, clapping, openly appreciative remark.
Practitioners generally describe it as a positive reaction; feminists see it as sexist and objectifying, up classify it as sexual aggression.