I did a database search on Snowy Plover and got no hits. As I really did not think you were missing this bird, I then tried the scientific name, Charadrius alexandrinus , and got the Kentish Plover. Are these the same birds? I assume so as both have the same scientific name. They should be listed in the database under both names as Snowy Plover is the name used in both the National Geographic and Sibley Guides and, I assume again, it is the name used on the western side of the Atlantic.