Northern Gannet vs Brown Booby

The Northern Gannet and Brown Booby are both large seabirds with plunge-diving behavior, but they differ significantly in plumage and habitat preferences. The Northern Gannet is predominantly white with black wingtips, while the Brown Booby has a distinctive dark brown body with a white belly. Both species are found in coastal areas, but the Northern Gannet prefers cooler northern waters, whereas the Brown Booby is more tropical.

Look for the white body with black wingtips of the Northern Gannet versus the dark brown body with a white belly of the Brown Booby. Consider the location: Northern Gannets are more likely in northern, cooler waters, while Brown Boobies are found in tropical regions. Juvenile Northern Gannets are mottled but still distinguishable by their larger size and different pattern compared to the consistent plumage of Brown Boobies.

Northern Gannets are generally larger and more robust than Brown Boobies.

Northern Gannets are mostly white with black wingtips, while Brown Boobies have a dark brown body with a contrasting white belly. Juvenile Northern Gannets are mottled brown and white, which could cause confusion with Brown Boobies, but the latter's consistent brown upperparts and white underparts are distinctive.

Both species are plunge-divers, but Northern Gannets often forage further from their colonies, sometimes several hundred kilometers, while Brown Boobies typically stay within 50 km of their nesting sites.

Northern Gannets breed in large colonies on cliffs in cooler northern waters, while Brown Boobies prefer tropical islands with flat, exposed nesting sites and are sensitive to human disturbance and introduced predators.