Grey-faced Petrel vs Kermadec Petrel

The Grey-faced Petrel and Kermadec Petrel can be distinguished by their plumage and behavior. The Grey-faced Petrel lacks the distinctive white flash on the underwing and white shafts on the primaries seen in the Kermadec Petrel, which also exhibits jaeger-like kleptoparasitic behavior.

Look for the white flash on the underwing and white shafts on the primaries to identify the Kermadec Petrel. Observe behavior: Kermadec Petrels may exhibit kleptoparasitism, unlike Grey-faced Petrels.

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

The Grey-faced Petrel is uniformly dark with a grey face, while the Kermadec Petrel has a white flash on the underwing and white shafts on the upper side of the primaries.

Kermadec Petrel exhibits jaeger-like behavior, known for kleptoparasitizing other seabirds, which is not observed in the Grey-faced Petrel.

Both species are pelagic, typically found in open ocean environments, but specific range details are not provided.