The Frigate Bird: Pirate Bird of the Galapagos
A group of six bachelors are spotted sitting together. They seem like friends hanging out socially, but really they’re all trying to pick up a lady, and competition is fierce. Through the posing and showing off, occasionally the bravado takes over and the men resort to spats of violence. Most striking on these gentlemen, the principal source of competition and the only feature that lures in the ladies, is a bright red pouch on their necks, inflated with air.
It takes the Frigate Bird about thirty minutes to fill their neck pouch up with air; when not inflated, it appears as a strip of red on the throat. The bigger the pouch, the more attractive it is to the females, who do not have a red pouch: just a white spot on their throats. As with any feature designed to entice the opposite sex, the largest and brightest is both the most attractive to females and the most intimidating to other males. A group of scientists inflated red balloons in a variety of sizes and placed them near the male frigate birds. The balloons that were inflated to a size larger than the bird’s own pouch made them nervous.
To attract females, the males sit together in a group, pouches inflated, hormone levels high. If there is a squabble, they may puncture the pouch of another with their sharp, pointed beaks. A minor puncture could take a frigate bird out of the running for a mate for the next few days. A large puncture could mean the victim of the attack is unable to attract a partner for the remainder of the mating season.
When a female frigate bird selects a male among the group, the birds have a two-week “honeymoon” flying over the ocean together. Upon their return, they will build a nest and the female will lay eggs, then both parents will tend to their offspring. Aside from the color on their throats, the male and female frigate birds are identical: large black birds with a wingspan of approximately 7.5 feet, a long, narrow beak that has a sharp curve ending in a point at the tip, a round, smooth head, and a deeply forked tail used to make sharp turns in flight. These are some of the fastest species of sea birds, evolved for speed—a blessing, due to the fact that they are unable to enter the water.
Frigate means pirate, and the frigate birds truly are the pirates of the seabirds. Most seabirds have a uropygial gland, an oil gland located above the tail. The typical seabird will touch their beak to the oil gland, then preen their feathers with the oil, waterproofing themselves. This allows birds like the blue footed booby or the albatross to dive into the sea for fish. The frigate bird does not have such an oil gland, so they have two options: to skim the surface of the water for fish (not very effective), or to steal caught fish from the beaks of other seabirds, typically as they are attempting to feed their young.
Another downside of being unable to waterproof themselves with oil: the frigate birds are also unable to land on the water to sleep during a long journey. Instead, during long flights with no land in sight, these birds are able to shut down one half of their brain at a time to sleep, allowing them to rest. The only ones who suffer during these long flights are the frigate offspring, too young to fly, awaiting a meal from mom or dad.
Frigate birds can be spotted along the coastline of much of South America: mainly Colombia, northern Brazil, Peru, and Ecuador. They are especially easy to observe in the Galapagos Islands. If you are interested in visiting Ecuador or the Galapagos Islands to learn more about this unique culture, contact us about one of our itineraries.