By Charlie Sobczak; Island Reporter, Captiva Current, Sanibel-Captiva Islander
One of the most efficient flying birds in the world, the magnificent frigatebird rivals the albatross family in its ability to remain airborne for extended periods of time. Extremely light and with an enormous wingspan, it has the lowest wing-loading (weight to wingspan) of any bird in the world. Seemingly suspended in the breeze, the frigatebird resembles a kite or large black bat soaring high overhead.
The frigatebird is kleptoparasitic, a feeding characteristic most often found in insects but also observed in certain birds. This means that the frigatebird will often harass a gannet, anhinga, or booby into disgorging its catch, then snatch it away from the other bird in midair — hence the nickname, pirate of the sea.
On the open ocean the frigatebird survives on squid, jellyfish, fish, and even young sea turtles. A truly spectacular flyer, the frigatebird has been observed synchronizing its speed and aligning its direction perfectly to snatch flying fish while the fish is airborne! In the Florida Keys, this behavior makes the frigatebird a welcome sight for anglers searching for the pelagic fishes of the Gulf Stream (dolphin, wahoo, marlin, and tuna) because the frigatebird tends to follow these fish in hopes of feeding on their by-catch or capturing the flying fish fleeing before them.
The male frigatebird has a large red pouch that it inflates during breeding season. The chicks of the frigatebird are pure white and extremely vulnerable to predation. They remain with the mother for more than a year after hatching, and because of the risk of being killed by other nesting frigatebirds, they are never left unattended. Because of this lengthy upbringing, the female frigatebird mates once every other year.
The frigatebird has been known to get swept up in major storms. In 1988 Hurricane Gilbert carried a flock deep into North America, leading to record sightings as far north as Ontario. Recent DNA testing has shown that the frigatebird is more closely related to the penguin than to the pelican family where most scientific literature still places it. Most predation to the frigatebird comes at the nesting site. It has no known predators once this large bird is at sea.
This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.
