Xantus's murrelet  (Synthliboramphus hypoleucus)

This small marine bird belongs to the genus Synthliboramphus, a group of seabirds remarkable for the fact that they are the only seabirds which rear their young entirely at sea (3). Xantus's murrelet has striking black and white plumage: black on the upperparts, sometimes tinted faintly with grey as the feathers become worn, and snowy white on the underside. The flanks may be white or mottled grey and white, the legs are bluish-grey, and the feet bear black claws (2). Two subspecies of Xantus's murrelet are recognised: Synthliboramphus hypoleucus hypoleucus and Synthliboramphus hypoleucus scrippsi. The former can be recognised by the prominent white crescents above and below the eye, while the white patterning on the face of S. h. scrippsi is very indistinct (2) (4). Female Xantus's murrelets are usually larger than the males, while juveniles may be distinguished by the scattered dark barring along the flanks (2). This seabird calls with a shrill whistle (4).