Pacific Loon (Gavia pacifica) (left) and Common Loon	(Gavia immer)  This distant digiscoping photo shows both a common loon (on the right) and a Pacific loon (on the left) as a birder might see them in the field.  Although they were small and distant, differences between the species can be seen.  The common loon is larger and has a heavier bill.  The Pacific loon is smaller, has a thinner bill, and a whiter neck and breast.  This pair was photographed at Cayuga Lake in western New York State on Feb 11, 2006.  Pacific loons are quite rare in New York State. Red-throated Loon (Gavia stellata) Nonbreeding Adult  Photogaphed at the Irondequoit Bay outlet near Rochester, NY on March 13, 2015.