Great Black-backed Gull vs Buller's Shearwater

In short

The Great Black-backed Gull is a large, robust gull with a striking black back and wings, while Buller's Shearwater is a medium-sized seabird with a distinctive gray and white plumage pattern. These species are not closely related, making structural differences and habitat preferences key for identification.

Identification tips

1. Size and bulk: Great Black-backed Gull is much larger and bulkier. 2. Plumage pattern: Look for the black back of the gull versus the gray back and 'M' wing pattern of the shearwater. 3. Habitat: Consider the location; Great Black-backed Gulls are coastal, while Buller's Shearwaters are oceanic. 4. Behavior: Note feeding habits; shearwaters often follow trawlers and associate with other seabirds.

Size

The Great Black-backed Gull is significantly larger and bulkier than Buller's Shearwater.

Plumage

Great Black-backed Gull has a black back and wings with white underparts, whereas Buller's Shearwater features a gray back with white underparts and a distinctive 'M' pattern across its wings.

Behaviour

Great Black-backed Gulls are opportunistic feeders often found near water bodies, while Buller's Shearwaters are pelagic, often seen associating with other seabirds and following trawlers.

Habitat

Great Black-backed Gulls are typically found near coastal areas and islands, whereas Buller's Shearwaters are oceanic, breeding on islets in New Zealand and dispersing widely across the Pacific.

Voice

Vocalizations are not a primary distinguishing feature in the field for these species.