I was vaguely aware of the term devil bird for Anhingas, but I can't help but assume that they used it in the title to make people think it was some kind of dangerous invasive that was imported. There are standard common names for North American birds. It's not like fish where there's a number of common names depending on the region. If you're writing an article about a bird species and you happen to use the scary-sounding non-standard name for it, I'm going to assume it's intentional to scare people.
Anyway, Anhingas are pretty common further south on the coast and occupy more or less the same niche as cormorants. Fishermen don't like them, but they don't like a lot of birds that eat fish.
Edit: Subject-verb agreement. Forgot how to grammar there. Probably missed something else too.