Band-rumped storm petrel

The band-rumped storm petrel, Madeiran storm petrel, or Harcourt's storm petrel (Hydrobates castro) is a species of storm petrel in the family Hydrobatidae.

The band-rumped storm petrel is 19–21 cm (7.5–8.3 in) in length with a 43–46 cm (17–18 in) wingspan, and weighs 44–49 g (1.6–1.7 oz). It is mainly brownish black with an extensive white rump. Similar to Leach's storm petrel with the forked tail, long wings, but Leach's has a more deeply forked tail, a differently shaped (V-shaped or triangular) white rump, and a 'tern-like' flight, whereas the band-rumped storm-petrel has a more 'shearwater-like' flight.