Silver Gull vs Black-billed Gull

In short

The bill color is the most reliable field mark: the Silver Gull has a red bill, while the Black-billed Gull has a black bill. Both species are similar in size and structure, but subtle differences in plumage and behavior can help with identification.

Identification tips

• Bill color: Silver Gull has a red bill; Black-billed Gull has a black bill.
• Location: Silver Gulls are more common in Australia, while Black-billed Gulls are native to New Zealand.
• Habitat preference: Silver Gulls are often seen in urban areas; Black-billed Gulls prefer inland waterways.
• Plumage: Look for subtle differences in wingtip coloration, with Black-billed Gulls having more extensive black.

Size

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

Plumage

The Silver Gull typically shows a white head and underparts with a light gray back and wings, and black wingtips with white spots. The Black-billed Gull also has a white head and underparts but may appear slightly paler overall, with more extensive black on the wingtips.

Behaviour

Both species exhibit typical gull behavior, often seen in flocks and scavenging near water bodies. The Silver Gull is more likely to be found in urban areas.

Habitat

Silver Gulls are commonly found in coastal and urban areas, while Black-billed Gulls are more often associated with inland rivers and lakes in New Zealand.

Voice

Vocalizations are similar, with both species producing typical gull-like calls. Specific differences in calls are not well-documented.