Manx Shearwater vs Black-vented Shearwater

In short

The Manx Shearwater and Black-vented Shearwater can be distinguished primarily by their plumage and geographic range. Manx Shearwaters have a more contrasting black-and-white appearance, while Black-vented Shearwaters show a more uniform dark upper side. Observing location can also aid identification, as their ranges rarely overlap.

Identification tips

• Location: Check geographic range; Manx in the North Atlantic, Black-vented in the Pacific.
• Plumage: Look for the sharp contrast in Manx versus the more uniform dark of Black-vented.
• Flight: Observe flight style; both glide and flap similarly, so focus on plumage and location.

Size

Both species are similar in size, but the Manx Shearwater may appear slightly more slender.

Plumage

Manx Shearwater has a stark black upper side and white underside, with a sharp demarcation line. In contrast, the Black-vented Shearwater has a more uniform dark upper side with less contrast between the upper and lower parts.

Behaviour

Both species exhibit similar flight patterns with stiff-winged glides and rapid wingbeats. There are no significant behavioral differences noted in the sources.

Habitat

Manx Shearwaters are typically found in the North Atlantic, while Black-vented Shearwaters are more common in the Pacific off the coast of California and Baja California. Their habitats do not usually overlap.

Voice

Vocalizations are not a reliable field mark for distinguishing these species, as they are rarely heard at sea.