Magnificent Frigatebird
Encyclopedia
The Magnificent Frigatebird (Fregata magnificens) was sometimes previously known as Man O'War, reflecting its rakish lines, speed, and aerial piracy of other bird
s.
It is widespread in the tropical Atlantic
, breeding colonially in trees in Florida
, the Caribbean
and Cape Verde Islands. It also breeds along the Pacific coast of the Americas
from Mexico to Ecuador including the Galapagos Islands
.
It has occurred as a vagrant
as far from its normal range as the Isle of Man
, Denmark, Spain, England
, and British Columbia
.
The Magnificent Frigatebird is 100 cm (39 inches) long with a 215 cm (85 inch) wingspan. Males are all black with a scarlet throat pouch which is inflated like a balloon in the breeding season. Although the feathers are black, the scapular feathers produce a purple iridescence when they reflect sunlight. Females are black, but have a white breast and lower neck sides, a brown band on the wings and a blue eye ring. Immature birds have a white head and underparts.
This species is very similar to the other frigatebird
s and is similarly sized to all but the Lesser Frigatebird
. However, it lacks a white axillary spur, and juveniles show a distinctive diamond-shaped belly patch.
The Magnificent Frigatebird is silent in flight, but makes various rattling sounds at its nest.
This species feeds mainly on fish, and also attacks other seabird
s to force them to disgorge their meals. Frigatebirds never land on water, and always take their food items in flight.
It spends days and nights on the wing, with an average ground speed of 10 km/hour, covering 223±208 km before landing. They alternately climb in thermal
s, to altitudes occasionally as high as 2500 m, and descend to near the sea surface (Chastel et al. 2003). The only other bird known to spend days and nights on the wing is the Common Swift
.
A scientific study that examined gene
tic and morphological variation in 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 most of the distribution range. This included evidence of recent gene flow among Pacific and Atlantic localities, likely across the Isthmus of Panama
. This geological formation is a strong barrier to movement in most tropical seabirds. However, the same study also found that the Magnificent Frigatebird on the Galapagos Islands
is genetically and morphologically distinct. Based on this study, the Galapagos population has not been exchanging any genes with their mainland counterparts for several hundred thousand years.
Given these findings, the Galapagos population of this tropical seabird may be its own genetically distinct species warranting a new conservation status. This small population of genetically unique Magnificent Frigatebirds is a vulnerable population. Any catastrophic event or threats by humans could wipe out the approximate 2,000 Magnificent Frigatebirds that nest on the Galapagos Islands. Magnificent Frigatebirds are currently classified as Least Concern
(LC)' by the International Union for Conservation of Nature, but the Proceedings of the Royal Society paper recommends that, because of the genetic uniqueness of those on the Galápagos, this status be revisited.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s.
It is widespread in the tropical Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, breeding colonially in trees in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
and Cape Verde Islands. It also breeds along the Pacific coast of the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
from Mexico to Ecuador including the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
.
It has occurred as a vagrant
Vagrancy (biology)
Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
as far from its normal range as the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
, Denmark, Spain, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, and British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
.
The Magnificent Frigatebird is 100 cm (39 inches) long with a 215 cm (85 inch) wingspan. Males are all black with a scarlet throat pouch which is inflated like a balloon in the breeding season. Although the feathers are black, the scapular feathers produce a purple iridescence when they reflect sunlight. Females are black, but have a white breast and lower neck sides, a brown band on the wings and a blue eye ring. Immature birds have a white head and underparts.
This species is very similar to the other frigatebird
Frigatebird
The frigatebirds are a family, Fregatidae, of seabirds. There are five species in the single genus Fregata. They are also sometimes called Man of War birds or Pirate birds. Since they are related to the pelicans, the term "frigate pelican" is also a name applied to them...
s and is similarly sized to all but the Lesser Frigatebird
Lesser Frigatebird
The Lesser Frigatebird, Fregata ariel, is a species of frigatebird.It nests in Australia, among other locations.There is a single record from the Western Palearctic, from Eilat in the Gulf of Aqaba....
. However, it lacks a white axillary spur, and juveniles show a distinctive diamond-shaped belly patch.
The Magnificent Frigatebird is silent in flight, but makes various rattling sounds at its nest.
This species feeds mainly on fish, and also attacks other seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s to force them to disgorge their meals. Frigatebirds never land on water, and always take their food items in flight.
It spends days and nights on the wing, with an average ground speed of 10 km/hour, covering 223±208 km before landing. They alternately climb in thermal
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
s, to altitudes occasionally as high as 2500 m, and descend to near the sea surface (Chastel et al. 2003). The only other bird known to spend days and nights on the wing is the Common Swift
Common Swift
The Common Swift is a small bird, superficially similar to the Barn Swallow or House Martin. It is, however, completely unrelated to those passerine species, since swifts are in the separate order Apodiformes...
.
A scientific study that examined gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
tic and morphological variation in 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
Gene flow
In population genetics, gene flow is the transfer of alleles of genes from one population to another.Migration into or out of a population may be responsible for a marked change in allele frequencies...
across most of the distribution range. This included evidence of recent gene flow among Pacific and Atlantic localities, likely across the Isthmus of Panama
Isthmus of Panama
The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
. This geological formation is a strong barrier to movement in most tropical seabirds. However, the same study also found that the Magnificent Frigatebird on the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
is genetically and morphologically distinct. Based on this study, the Galapagos population has not been exchanging any genes with their mainland counterparts for several hundred thousand years.
Given these findings, the Galapagos population of this tropical seabird may be its own genetically distinct species warranting a new conservation status. This small population of genetically unique Magnificent Frigatebirds is a vulnerable population. Any catastrophic event or threats by humans could wipe out the approximate 2,000 Magnificent Frigatebirds that nest on the Galapagos Islands. Magnificent Frigatebirds are currently classified as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
(LC)' by the International Union for Conservation of Nature, but the Proceedings of the Royal Society paper recommends that, because of the genetic uniqueness of those on the Galápagos, this status be revisited.
External links
- Magnificent Frigatebird videos, photos & sounds on the Internet Bird Collection
- International Bird Rescue Research Center
- The Bird Rescue Center, a wild bird rehabilitation center.