Large-billed Tern vs Gull-billed Tern

In short

The Large-billed Tern is easily recognized by its large, heavy bill and striking wing pattern, while the Gull-billed Tern has a stocky build with a short, heavy black bill and a more uniform pale gray plumage. Both species have a black cap in breeding plumage, but the Large-billed Tern's distinctive wing pattern is a key differentiator.

Identification tips

1. Look for the large, heavy bill of the Large-billed Tern. 2. Note the striking wing pattern of the Large-billed Tern with black primaries and white secondaries. 3. Observe the uniform pale gray plumage of the Gull-billed Tern. 4. Check for the black cap in breeding adults of both species, but remember the Large-billed Tern's wing pattern is more distinctive. 5. Consider habitat: Large-billed Terns are more likely found along large rivers and lakes, while Gull-billed Terns have a broader habitat range.

Size

The Large-billed Tern is generally larger with a more robust bill compared to the medium-sized Gull-billed Tern.

Plumage

Large-billed Tern has black primaries, white secondaries, and a gray back, creating a striking contrast. Gull-billed Tern is more uniformly pale gray above with slightly darker primaries and a whitish to pale gray wingtips. Both have a black cap in breeding plumage, but the Gull-billed Tern's cap is more extensive.

Behaviour

Large-billed Terns often nest in mixed colonies with other species like Black Skimmers, while Gull-billed Terns have a wide-ranging distribution and can be found in various habitats.

Habitat

Large-billed Terns are found along broad inland rivers and lakes during breeding and coastal areas in nonbreeding season. Gull-billed Terns have a more varied habitat range, including coastal and inland waters.