The Northern Fulmar, a robust seabird of the North Atlantic and North Pacific, possesses a unique and highly effective defense mechanism. When threatened, this bird employs a biological weapon so potent it can prove lethal to other seabirds and ruin equipment for humans. This defense involves a highly viscous, foul-smelling substance that the bird can deploy with surprising accuracy. This adaptation ensures that any potential predator or intruder quickly learns to keep its distance.
The Northern Fulmar
This species, Fulmarus glacialis, belongs to the order Procellariiformes, a group of seabirds that includes petrels and albatrosses. Northern Fulmars are abundant in subarctic and northern temperate waters, spending most of their lives soaring over the open ocean before coming to nest on rocky cliffs and islands. They are often mistaken for gulls due to their size and plumage, which varies between a light morph (white body with gray wings) and a dark morph (uniformly gray). An adult fulmar typically measures between 45 and 50 centimeters in length, with a large wingspan often exceeding one meter.
The Defensive Mechanism
The fulmar’s potent defense is a lipid-rich secretion known as stomach oil, stored in the proventriculus (the fore-gut of its digestive system). This oil is not secreted by the bird itself but is a highly concentrated residue derived from the fatty prey it consumes, such as krill, squid, and fish. Chemically, the oil is composed primarily of neutral dietary lipids, making the substance extremely energy-dense, with a calorific value only slightly lower than diesel oil.
When a Fulmar feels threatened, it can forcefully eject this stomach oil in a projectile manner, sometimes reaching distances of up to three meters. This defensive action is employed against threats ranging from avian predators like skuas to human climbers. The deployment of the oil is an immediate and effective deterrent, coating the target in a sticky, odorous substance. The bird’s ability to store this energy-rich material also serves a dual purpose, as the high-caloric oil is fed to their chicks during periods of food scarcity.
The Devastating Effects of Fulmar Oil
The oil’s effectiveness as a weapon lies in its highly viscous nature and its devastating effect on the water-repellent properties of feathers. When another bird is struck, the substance immediately mats the delicate structure of its plumage. This contamination destroys the bird’s natural insulation and waterproofing.
A seabird coated in Fulmar oil is quickly rendered incapable of flight and becomes waterlogged upon entering the ocean. Once the waterproofing is compromised, the bird loses buoyancy and rapidly sinks. The resultant loss of insulation leads to rapid hypothermia, often resulting in death by exposure or drowning. For humans, the oil is not physically dangerous, but its repulsive, fishy odor and sticky texture cling tenaciously to clothing and equipment, often necessitating the discarding of affected items.