Jeff Wells is a noted Maine birder with a nice web site. He talks about gulls hawking ants here http://www.borealbirds.org/blog/?p=198
If you want to know more about Charles_Lucien_Bonaparte the ornithologist, click on his name.
Paul Garritty also has a nice birding site in Maine. Here's a link to his page on gulls in Maine: mainebirding.net/birds/GullsTerns
Thanks to Wikipedia, allaboutbirds.com and David Allen Sibley's The Sibley Guide To Birds for some of the information.