American Bittern, Botoris lentigenosis
The out-in-the-open views in the first four pictures of American Bitterns on this page are very much the exception; the birds are much more commonly seen in the reeds, as shown above and in the two below, the habitat for which their plumage serves as an effective camouflage.
Bitterns are patient foragers, waiting perfectly still by fresh water until their prey (here a crayfish) comes within striking distance. For a four-image sequence concluding with the picture above, see here.