Hydrobates pelagicus
Rarely seen, small petrel. Compact with shorter wings and tail, and blacker plumage than Leach's Storm-Petrel. Squared, unforked tail. White patch on upper tail coverts that reaches down on each side, with more square-cut edges than in Leach's. Also lacks the grey upper wing-band of latter, but shows white stripe on underside of wing. Flight-pattern bat-like with quick fluttering wing-beats and less powerful, and only short, gliding sequences. Sometimes patters with feet on the surface or rests on water. Visits breeding ground at night.
Heard at breeding ground. Dry, cyclic, rattling and cooing, interrupted by deeper nasal moaning or a higher pitched "kee-ee-kee", with emphasis on second syllable.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
