Frigate birds are seabirds found across tropical and subtropical oceans, known for their long, narrow wings, deeply forked tails, and hooked bills. While they spend most of their lives soaring over the ocean, their feeding habits are diverse, including both self-caught prey and food acquired through unique means.
Primary Ocean Diet
Frigate birds predominantly feed on fish and squid, which they snatch from the ocean’s surface. They rarely land on the water due to their non-waterproof plumage. Instead, they swoop low, grabbing prey like flying fish or squid often driven to the surface by larger marine predators such as tuna or mahi-mahi. Their hooked bills are well-suited for grasping these slippery targets mid-flight.
This aerial fishing requires exceptional agility and precision. Frigate birds use their impressive wingspan, which can reach up to 7.5 feet, to maneuver swiftly just above the waves. They also consume other surface-dwelling organisms like jellyfish, crabs, and larger plankton. Occasionally, they follow fishing vessels, opportunistically taking discarded fish.
Aerial Food Theft
Frigate birds are renowned for kleptoparasitism, a behavior involving stealing food from other seabirds. They are often called “man-o’-war birds” or “sky pirates” due to this aggressive tactic. They pursue birds like boobies, gulls, terns, and tropicbirds, harassing them relentlessly in mid-air.
The frigate bird chases and pecks at its victim, sometimes grabbing its tail or wing, until the harassed bird regurgitates its recently caught meal. With speed and maneuverability, the frigate bird then dives and snatches the falling food before it hits the water. Kleptoparasitism supplements their diet rather than being a primary food source, accounting for only a small percentage of their total food intake.
Varied Foraging Opportunities
Beyond their primary ocean diet and aerial thievery, frigate birds demonstrate an opportunistic feeding strategy, expanding their diet based on availability. They prey on the eggs and hatchlings of other ground-nesting seabirds, such as sooty terns. This behavior provides an important food source, especially during their own breeding seasons when energy demands are high.
Frigate birds also consume insects caught in flight, showcasing their adaptability. They may scavenge carrion or refuse found around human settlements or docks. These varied foraging methods allow frigate birds to sustain themselves in diverse environments and when preferred prey might be scarce.