Kermadec Petrel vs Herald Petrel

The Kermadec Petrel and Herald Petrel are both medium-sized seabirds with similar jaeger-like behaviors, but they can be distinguished by plumage details. The Kermadec Petrel has distinctive white shafts on the upper side of the primaries and a white flash on the underwing, while the Herald Petrel lacks these features.

Look for the white shafts on the upper side of the primaries and white flash on the underwing to identify the Kermadec Petrel. In contrast, the Herald Petrel will appear more uniformly dark without these white markings. Observing behavior, such as kleptoparasitism, can also provide clues, though both species share this trait.

Both species are similar in size, typical of medium-sized petrels.

Kermadec Petrel shows white shafts on the upper side of the primaries and a white flash on the underwing. The Herald Petrel lacks these white markings, making it more uniformly dark.

Both species exhibit jaeger-like behavior, including kleptoparasitism, which is unusual for petrels.

Both species are pelagic and can be found in similar oceanic habitats, often far from land.