Magnificent Frigatebird, Fregata magnificens

The Magnificent Frigatebird (Fregata magnificens) was occasionally previously known as Man O’War or man of War, a reflection of its rakish lines, aerial piracy of other birds, and speed.

It’s widespread in the tropical Atlantic, breeding colonially in the trees in Florida, the Caribbean and the Cape Verde Islands. In addition, it breeds along the Pacific coast of the Americas from Mexico to Ecuador including the Galapagos Islands, as well.

It is known as a vagrant as far from its normal range as the Isle of Man, Denmark, England, Spain, and British Columbia.

This bird is 39 inches long with an 85 inch wingspan. The males are colored all-black with a scarlet throat pouch that inflates like a balloon during the breeding season. Although the feathers are black, the scapular feathers create a purple iridescence when they reflect the sunlight. The females are black, but have a white breast and lower neck sides, a blue eye-ring that is indicative of the female of the species, and a brown band on the wings. The immature birds’ head and underparts are white.

This species is much like the other frigatebirds and is similarly sized to all but the Lesser Frigatebird. However, it lacks a white axillary spur, and the juveniles how a distinctive diamond-shaped patch on their belly.

It is silent while in flight, but makes various rattling sounds while in the nest.

It mainly feeds on fish, and also attacks other seabirds, forcing them to disgorge their meals. Frigatebirds never land on water, and they always take their food items in flight.

It spends the days and nights on the wings, with and average ground speed of 10 km per hour. They alternately climb in thermals, to altitudes sometimes as high as 2,500 m, and descend to near the surface of the sea. The only other bird known to spend their days and nights on the wing is the Common Swift.

A scientific study that examined genetic and morphological variation in the Magnificent Frigatebirds found both expected, and also highly unexpected results: firstly – as predicted by the flight capacity of the species – the authors found signatures of high gene flow across the majority of the distribution range. This included evidence of recent gene flow amongst Pacific and Atlantic localities, likely across the Isthmus of Panama. This geological formation is a strong barrier to movement in the majority of topical seabirds. However, the same study also found the Magnificent Frigatebird on the Galapagos Islands is genetically and morphologically unique. Based on this study, the Galapagos population hasn’t been exchanging any genes with their mainland counterparts for several hundred thousand years.

Given these findings, the Galapagos population of this tropical seabird might be its own genetically unique species warranting a new conservation status. This small population of genetically unique Magnificent Frigatebirds is a susceptible population. Any catastrophic event or threats by humans could obliterate the approximate 2000 Magnificent Frigatebirds that nest on the Galapagos Islands.

These birds are currently listed as Least Concern by the International Union for Conservation of Nature, but the Proceedings of the Royal Society paper recommends that, because of the genetic individuality of those on the Galapagos, this status be revisited.

Image Caption: A male Magnificent Frigatebird in the Galapagos Archipelligo, Ecuador. Credit: Andrew Turner/Wikipedia (CC BY 2.0)