Black-vented Shearwater vs Fluttering Shearwater

Black-vented Shearwater

Puffinus opisthomelas

Large408 gMarine

Black-vented shearwater adults are around 30–38 cm in length, have a 76–89 cm wingspan and weigh around 400 g. Males are generally slightly larger than females, though the size difference is minimal. Chicks have grey down feathers, lighter around their throat and breast areas. These down feathers lighten slightly over time. Adults have dark brown heads, and dorsal plumages, with lighter ventral plumage (often white with specks and smudges of brown). This is like many other diving and marine bird species, which use countershading as a method of camouflage. Voice: Although there are few records of black-vented shearwater calls, their vocalizations have been likened to a moaning growl, similar to the sound of a dentist's drill and suction. The black-vented shearwater only calls at night, when there is little to no moon. Vocalizations are believed to play a significant role in mating, as the species lacks sexual dimorphism, akin to the Manx shearwater.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Madeleine Claire · CC BY 4.0

Fluttering Shearwater

Puffinus gavia

Medium229 gMarine

This is a medium to small-sized shearwater with a dark-brown-and-white body. The upper parts, including neck, wings and tail, are uniformly dark brown. The face and neck have a grey-brown colour gradually fading into white below the eye. The under body, from chin to the under-tail, is white except for a dark thigh patch that can be seen in flight. The bottom wing is commonly white while the axillary area is covered in grey-brown fur. Under light conditions, the appearance is different.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Natewilbournee · CC0

Photos and recordings are credited to their authors under the licence shown. Full profiles: Black-vented Shearwater and Fluttering Shearwater.