In North America there are two types of waterthrushes, the Northern Waterthrush can be found across the continent except for some areas along the southwest coast. The Louisiana Waterthrush, which is very similar in size and appearance, lives in the southern regions of Canada to Florida and into Mexico.
The waterthrushes are members of the warbler family. These birds can be found along streams in wooded areas and in forests, hopping from rock to rock, going in and out of the water while searching for food. They are known for their habit of always bobbing their tails up and down as they move about.
Avibase - the world bird database This site provides the user with a complete list of bird species, broken down per country, or in the example of the US or Canada, per state and province. Here, bird species names are available in other languages, a great asset to be used as a translation of foreign bird names.
ABA - American Birding Association This site represents an organization that maintains official records of all birds species that have been proven to have been seen inside the perimeters of the North American Continent and the surrounding bodies of water. Regular revised versions are posted to keep the bird list current at all times. This is the list used by all serious birders over their lifetime. You may be aware of the movie called the "Big Year". It was with this list that all the competing birders used in an attempt to set a new record as to how many bird species that could be seen by an individual birder in one calendar year.
I hope you will take advantage of these suggested websites. I have used each of them, in one way or another, throughout the years in my quest to better identify and understand our fine feathered friends.