Birds have many unique ways to find mates during mating season. Sometimes they dance, sometimes they sing, and sometimes they collect shiny objects for their potential partners. One bird whose mating signal differs from the rest is the frigatebird. As seen in this video by BBC Earth, frigatebirds have an inflatable red neck to attract mates. Keep reading below to learn what these pouches signify during the frigatebird’s mating season.
©191271636/Shutterstock.com
About the Frigatebird
Frigatebirds inhabit tropical and subtropical oceans throughout the world, such as the Caribbean Islands, the Galápagos Islands, Madagascar, and more. Rather than living on these islands full-time, the birds spend the majority of their time flying over the open ocean. They use the islands for breeding and resting, with breeding taking place on more remote islands. They are long and slender with pointed wings, and the males are notable for their red, inflatable pouches. This red contrasts sharply with their black and dark brown feathers. Their wingspan can reach between six and eight feet, and they normally weigh around four pounds.
When the birds aren’t resting in the shrubs and mangroves of remote islands, they spend their time flying over the open ocean. Due to their evolution, the birds are poor swimmers, making it dangerous to rest on the water. They make up for this through their excellent hunting. Given their large wingspan and low body weight, they can ride ocean air currents, gliding for hours or even days on end. By staying in flight, they can spot their prey, such as squid and flying fish, with ease. While it may seem exhausting to stay aloft so long, frigatebirds are well-suited for this lifestyle.
Frigatebirds will keep their pouches inflated throughout the day until they find a mate.
©iStock.com/ksumano
Mating Rituals
The red, inflatable pouch on male frigatebirds is known as the red gular sac. This is a skin pouch at the base of the throat, similar to those found in pelicans, herons, and frogs. During mating season, the male frigatebirds pump the sac full of air, and it can grow to the size of a basketball! It takes the birds around 20 minutes to inflate the sac, and they will display it for extended periods each day during the mating season until a mate is found. This is a mating display, and similar to other mating behaviors in birds, the brighter and more noticeable, the better. A frigatebird with a larger and more brightly colored pouch signifies a healthy and strong male to the females. While the males display in the shrubs, the females fly overhead, inspecting which male they want to mate with.
This is known as a lek system, a form of mating ritual where males compete against each other in groups. Being able to inflate the pouch longer than the competition means that the frigatebird has plenty of energy. A bright pouch signifies a strong diet and good feeding, which is ideal for finding a mate and raising offspring. Along with this visual display, they produce a clacking sound by rapidly opening and closing their beaks. They will also drum on their inflated pouches at the same time. This addition to the visual display allows the male to stand out even more, attracting a mate even if his pouch is not the largest or brightest.
