When should I use「かも」 versus 「アヒル」?


My Japanese friend uses the work ｢アヒル」when referring to ducks in a public
park. However, another Japanese friend uses 「鴨」（かも）in similar situations.

In English, as far as my limited knowledge of the animal kingdom goes, we just
have the word "duck". Can anyone explain the difference between these two
words? Which is more common (and more correct) in the situation I've outlined?
And do the rules change if we're talking about duck as a dish in a restaurant?




Referring to [Japanese
Wikipedia](http://ja.wikipedia.org/wiki/%E3%82%AB%E3%83%A2), it seems the main
difference is that `アヒル` is used for [domestic
ducks](http://en.wikipedia.org/wiki/Domestic_duck) and `鴨` for [wild
ducks](http://en.wikipedia.org/wiki/Wild_duck).

According to this [Chiebukuro
post](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1225531217),
`家鴨{あひる}` "house duck" came about due to selective breeding from `真鴨{まがも}`
"true duck" or "[mallards](http://en.wikipedia.org/wiki/Mallard)". Apparently
the former is a tame duck created for food and enjoyment.

I think there's a fair amount of overlap in practical usage, but that `アヒル`
might sound slightly more feminine/cuter than `鴨`. This is just anecdotal, but
I've often seen `アヒル` used in that kind of way in Anime etc, and I've seen
some females use pen-names of `アヒル` but never `カモ`. It also might be worth
noting
[アヒル口](http://ja.wikipedia.org/wiki/%E3%82%A2%E3%83%92%E3%83%AB%E5%8F%A3),
which is apparently regarded for it's "cuteness" and "sexiness" according to
Wikipedia.




Referring to [Japanese
Wikipedia](http://ja.wikipedia.org/wiki/%E3%82%AB%E3%83%A2), it seems the main
difference is that `アヒル` is used for [domestic
ducks](http://en.wikipedia.org/wiki/Domestic_duck) and `鴨` for [wild
ducks](http://en.wikipedia.org/wiki/Wild_duck).

According to this [Chiebukuro
post](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1225531217),
`家鴨{あひる}` "house duck" came about due to selective breeding from `真鴨{まがも}`
"true duck" or "[mallards](http://en.wikipedia.org/wiki/Mallard)". Apparently
the former is a tame duck created for food and enjoyment.

I think there's a fair amount of overlap in practical usage, but that `アヒル`
might sound slightly more feminine/cuter than `鴨`. This is just anecdotal, but
I've often seen `アヒル` used in that kind of way in Anime etc, and I've seen
some females use pen-names of `アヒル` but never `カモ`. It also might be worth
noting
[アヒル口](http://ja.wikipedia.org/wiki/%E3%82%A2%E3%83%92%E3%83%AB%E5%8F%A3),
which is apparently regarded for it's "cuteness" and "sexiness" according to
Wikipedia.

