Great Frigatebird vs Brown Booby

In short

The Great Frigatebird and Brown Booby are both seabirds but differ significantly in appearance and behavior. The Great Frigatebird is known for its large size, deeply forked tail, and the male's distinctive red gular sac. In contrast, the Brown Booby is smaller, with a more robust body and engages in plunge-diving to catch prey.

Identification tips

• Size and Shape: Look for the larger size and deeply forked tail of the Great Frigatebird.
• Plumage: Note the glossy black plumage and red gular sac in male Great Frigatebirds versus the brown and white contrast in Brown Boobies.
• Behavior: Observe the flight style; Great Frigatebirds soar effortlessly, while Brown Boobies dive into the water.

Size

The Great Frigatebird is larger with a wingspan that can reach up to 2.3 meters, while the Brown Booby is more compact with a wingspan of about 1.5 meters.

Plumage

Great Frigatebirds have predominantly black plumage with a glossy sheen, and males have a striking red gular sac. Brown Boobies have a contrasting brown head and upperparts with white underparts, making them easily distinguishable.

Behaviour

Great Frigatebirds are aerial specialists, often seen soaring and rarely landing on water. They are known for kleptoparasitism but catch most of their food independently. Brown Boobies are adept divers, performing plunge-dives to catch fish.

Habitat

Both species are found in tropical and subtropical oceans, but Great Frigatebirds are more pelagic, often seen far from land, while Brown Boobies prefer coastal areas and islands for nesting.