Brown Booby vs Masked Booby

In short

The Brown Booby and Masked Booby are both large seabirds with distinct plumage differences. The Brown Booby has a dark brown head and upperparts with a contrasting white belly, while the Masked Booby is primarily white with a black mask around the eyes and black flight feathers. In the field, these plumage differences are the most reliable identification features.

Identification tips

• Plumage: Look for the dark brown head and upperparts of the Brown Booby versus the white body and black facial mask of the Masked Booby.
• Size and Structure: Note the slightly larger and more robust build of the Masked Booby.
• Flight Pattern: Observe the direct flight of the Masked Booby compared to the Brown Booby's more varied diving behavior.

Size

Both species are similar in size, but the Masked Booby is generally larger and more robust than the Brown Booby.

Plumage

The Brown Booby has a dark brown head, neck, and upperparts with a sharp contrast to its white underparts. The Masked Booby is predominantly white with a distinctive black mask around the eyes and black on the wings and tail.

Behaviour

Both species engage in plunge-diving to catch fish, but the Brown Booby may also perform more horizontal dives. The Masked Booby is known for its direct, powerful flight.

Habitat

Both species prefer nesting on isolated islands with minimal human disturbance. The Brown Booby often nests on cliff edges or sandy atolls, while the Masked Booby prefers flat, open areas.

Voice

Vocalizations are not a primary distinguishing feature in the field for these species, as both are generally silent at sea.