it would be IBIS. as in the glossy ibis
f
u
c
k
coot loon
Ruff
crow
Fowl
Yes, the word "cock," meaning a male bird, especially a rooster, is a four-letter word with two c's in it.
word
Rail.
ibis
duck
ROCS
skua
Crow.
A male bird is most commonly called a Cock.
The 4-letter root word meaning against or opposite is "anti."
Dove
The answer for a snipe-like shore bird is Knot.