There are 2 other green kingfishers found in this habitat that this one can be confused with, but, at 5 1/4 inches, this one is the smallest of them. Probably why it is called "pygmy". ;-)
The American Pygmy Kingfisher has a cinnamon collar, in contrast to the white collar of the Green Kingfisher and the Amazon Kingfisher.
A few days later I was able to get a look at and some better shots of another Pygmy while kayaking in the mangroves.
Unlike the Amazon Kingfisher, which is considerably larger (11 plus inches!), the Pygmy Kingfisher and the Green Kingfisher both have rows of white spots on their green wings. The female pygmy and green kingfishers have a green band across their breast.
This was a very friendly male who sat and talked to me for about 15 minutes while I photographed it from the kayak.