Frigatebirds, also
called Man of War birds or Pirate birds, are truly masters of the sky.
There are five species in
this amazing family (Fregatidae)--the Magnificent Frigate, the Great Frigate, the
Ascension Frigate, the Christmas Frigate, and the Lesser Frigate. They are large seabirds that are found
in tropical and subtropical ocean habitat.
Frigatebird
range shown in blue.
They were given their
nicknames due to their aggressive behaviors toward others birds. While in flight, Frigates will poke and
bite at other birds in order to steal their food. Even worse, Frigates will sometimes grab other seabirds in
flight by their tail feathers and shake them until they drop their meal or
regurgitate a recently swallowed meal!
This is called Kleptoparasitism, parasitism by theft.
Great
Frigatebirds chasing a Red-footed Booby in order to steal its food.
Frigatebirds have the
ability to fly extremely well and have excellent aerial control. The reason for this is their
wingspan. These birds have the
longest wingspan for their weight compared to any other bird. For example, the largest species, the
Magnificent Frigatebird, can have a wingspan of up to 7.5 feet and weighs only
3.3 pounds. In comparison, a bald eagle
with that same wingspan of 7.5 feet would weigh 12 to 14 pounds.
A male
Magnificent Frigatebird in flight.
Birds have an oil gland,
called the uropygium, at the base of their tails. Birds spread the oil from this gland on their feathers to
help their feathers stay waterproof. Frigatebirds only have a small
oil gland and thus their feathers have little
waterproofing. So they cannot dive
into the water, let alone swim in it like some other seabirds. They will capture their prey by snatching
it out of the water with their long beaks. They will also use their superb aerobics to catch flying
fish out of the air.
These birds cannot walk
well either, and will spend most of their time in the air, only landing to
roost, breed and nest on trees or cliffs. They can stay in the air out at sea for
more than a week! Frigatebirds are
the only seabirds in which the males and females are noticeably different. Both have iridescent black feathers as
adults, but females have a white underbelly and males have inflatable red
throat pouches called gular sacs.
Breeding pair
of Great Frigatebirds.
Frigatebirds are
seasonally monogamous and the males perform courtship displays for the females. The females fly above as the males perch on the tops of trees. The males will
inflate their red throat pouches, flap the ends of their wings and shake their
head. When a male is chosen, the
female will land by him and the male will respond by wrapping his wings around
the female to protect her from other males. Click here to see a video of a
male Great Frigatebird trying to attract a mate.
Male Great Frigatebird on display.
The Ascension Frigatebird
is listed as vulnerable and the Christmas Frigatebird is listed as critically
endangered by the IUCN Red List of Threatened Species. The Christmas Frigate is only found on
Christmas Island in the Indian Ocean.
Habitat loss, over-fishing, marine pollution, and entanglement in
fishing nets are all causes for their decline. Also, the accidentally introduced Yellow Crazy Ant attacks
and eats newly hatched chicks.
This ant has devastated the wildlife and ecology on the island.
If you want to help
endangered birds, the World Bird Sanctuary’s mission is to secure the future of
threatened bird species in their natural environments. You can help us fulfill our mission by simply visiting us and spreading what you’ve learned,
becoming a member or friend, or adopting-a-bird, which feeds that bird for a
year!
Submitted by Sara Oliver,
World Bird Sanctuary Naturalist
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