Rhinoceros Auklet, Cerorhinca monocerata
Adults above and below, in non-breeding plumage. These little birds can usually only be photographed swimming or flying away from a boat at a considerable distance; very rarely, as above, one will pop up near the boat in profile.
The birds above and below show the "rhino horn" that gives the species its common English
name, a light gray vertical protusion from the bill present during the breeding season.
The light-colored eye with dull orange bill and no "horn" show this to be a non-breeding adult; a juvenile would have a dark eye, as below. On this trip, instead of all flying straight away from the boat, a few of these elusive little birds flew alongside, allowing me to get my first flight shots of this species.
Above is a juvenile Rhinoceros Auklet, identified as such by the dark eye and mostly dark bill. This bird stayed put when our boat approached on the relatively smooth waters of protected Princeton Harbor.