Graceful Seabird Marauder: Magnificent Frigatebird
Tara A. Spears
One of the most amazing seabirds to watch at the beach is the pirate of the Pacific-the Frigatebird. In the lead photo you can see one stealing a pelican’s dinner before the pelican can swallow it. The spectacular Frigatebird is frequently seen hanging motionless in the air above Jaltemba Bay.
This distinctive seabird is easy to notice due to its unique profile: the Frigatebird’s tail is long, with extensive pointed forks. (Locals call them ‘tijeras’ Spanish for scissors.) Their legs are short, and the small, partially webbed feet are only used for perching. Frigate birds are very ungainly on the ground or in the water but airborne, they are a wonder to see.
Frigate birds typically weigh only about 3 pounds (1.5 kg) yet the spread of their long, narrow, pointed wings can exceed 6.5 feet (2 meters). Because of its aerodynamic characteristics, frigate birds are among the most skilled of all birds at flying and seemingly effortless gliding.
Frigatebirds are the ultimate gliders among birds, able to hang in the air for hours with hardly a movement of their long, angular wings. Inhabitant of warm seas, this species can be seen soaring over tropical coastlines or perched like gaunt statues on dead trees. Frigatebirds never swim, because their long wings (adapted for soaring) and tiny feet render them unable to take off from water; all their food is snatched from the surface in flight or stolen from other birds.
The tropical Magnificent Frigatebird’s preferred habitat is oceanic coasts and coastal islands with dense growth of mangroves or other trees and shrubs. Its diet consists of mostly fish including squid, jellyfish, and crustaceans. Frigatebirds also will take hatchling turtles, young terns and other birds, sometimes eggs. Opportunistic feeders, Frigatebirds will scavenge for scraps around fishing boats and docks.
Besides its ability to glide for long periods of time, Frigatebirds can hunt for food from the air, swooping close to water to take items from on or near surface, making very little contact with water. This bird never swims. Frigatebirds forage in same way over land, taking prey from beaches without landing.
Perhaps the specie’s most interesting behavior is the way that Frigatebirds feed by piracy. The sleek Frigatebird commonly swoop aggressively on pelicans, boobies, and gulls, poking them and biting the other birds’s tail and wings. This pugnacious behavior forces these birds to drop or disgorge any fish that they have recently caught and eaten, which is then consumed by the Frigatebird. This pirating food strategy is known to scientists as kleptoparasitism.
If you have gone whale watching or snorkeling at the Jaltemba Bay islands, you can see the massive breeding colonies of seabirds, including the Magnificent Frigatebird. The perched males display (often in groups) by inflating their throat pouch to huge red balloon, raising their bill high, vibrating partially spread wings, swiveling back and forth, and calling. Females flying overhead are attracted to group, choose one male as mate. The nests are built mostly by the female, with materials brought by male. The pair form a flimsy platform of sticks to lay eggs.
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Throughout human history birds have been equated with the supernatural. Flight itself is seen as an icon of transcendence, as a reaching to the sky world. Watching the sleek Frigatebirds hunt, glide, and fly one can envision how primitive societies believed these creatures to be gods.
