Wilson's Storm Petrel

Fascinating facts about the Wilson's Storm Petrel

• At roughly 19 centimetres long and 38 grams, Wilson's storm petrels are smaller than a sparrow—yet they cross the Atlantic Ocean twice a year, spending their northern summers breeding in Antarctica before vanishing into the North Atlantic for winter. No bird migrates farther relative to its body size.
• They walk on water. Wilson's storm petrels hover just above the ocean surface, dangling their legs and pattering their feet across the waves to pluck krill and fish larvae from the top 10 centimetres of the sea. Sailors called them 'Mother Carey's chickens' because they seemed to defy the laws of physics.
• Wilson's storm petrels may be the most abundant bird on Earth—somewhere between 10 and 20 million individuals. Yet almost nobody has ever seen one. They spend 90% of their lives hidden in the open ocean, appearing on land for just 4–5 months a year to breed in remote Antarctic islands.
• They navigate 16,000 kilometres across featureless ocean using magnetic fields, star position, and the scent of dimethyl sulphide—a smell released by krill that drifts downwind like an underwater breadcrumb trail. A single storm petrel can find a krill swarm in darkness from kilometres away by smell alone.
• Wilson's storm petrel chicks produce a foul-smelling projectile vomit—a waxy stomach oil mixed with krill—that coats attacking predators in a slick so slippery that rats and skuas lose their grip and slide off the rocky nesting site. It's a chemical mugging that works.

At a glance

About the Wilson's Storm Petrel

As the sun dips below the horizon, the Wilson's Storm Petrel takes to the sky, its delicate form silhouetted against the fading light as it dances on the wind, its rapid wingbeats a blur of motion. With an effortless glide, it rides the ocean's updrafts, its large eyes scanning the waves for the tiny crustaceans that sustain it, a true master of the marine realm. In its wake, a trail of tiny footprints on the water's surface is all that remains, a fleeting testament to the petrel's ephemeral presence in this vast and mysterious world.

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