Frigatebirds are a family of seabirds called Fregatidae which are found across all tropical and subtropical oceans. They have predominantly black plumage, long, deeply forked tails and long hooked bills.

Their wings are long and pointed and can span up to 2.3 metres (7.5 ft), the largest wing area to body weight ratio of any bird. Able to soar for weeks on wind currents, frigatebirds spend most of the day in flight hunting for food, and roost on trees or cliffs at night.

Their main prey are fish and squid, caught when chased to the water surface by large predators such as tuna. Frigatebirds are referred to as 'kleptoparasites' as they occasionally rob other seabirds for food, and are known to snatch seabird chicks from the nest.

Seasonally monogamous, frigatebirds nest colonially. A rough nest is constructed in low trees or on the ground on remote islands. A single egg is laid each breeding season.

The duration of parental care is among the longest of any bird species; frigatebirds are only able to breed every other year. Having the largest wing-area-to-body-weight ratio of any bird, frigatebirds are essentially aerial.

This allows them to soar continuously and only rarely flap their wings. One great frigatebird, being tracked by satellite in the Indian Ocean, stayed aloft for two months. They can fly higher than 4,000 meters in freezing conditions.

More Info: en.wikipedia.org