Birds
Shearwater
Ardenna spp. · also called shearwaters
Far from any coastline, a shearwater banks low over the water on stiff wings, appearing to cut straight through the crest of each passing wave, navigating toward a scattered patch of food it detected by scent alone from kilometres away.
Overview
The shearwater, genus Ardenna, is a long-winged seabird found across open ocean habitat worldwide, coming ashore only to nest in burrows on remote islands. Its stiff-winged gliding flight, powerful sense of smell, and extraordinary long-distance migrations make it one of the more remarkable open-ocean specialists among all birds.
A life spent almost entirely over water
Touching land only to breed, a shearwater spends the overwhelming majority of its long life gliding across open ocean, relying on smell rather than sight to guide it toward food scattered across an environment with almost no fixed landmarks at all.
Status
Least Concern — widespread across suitable open ocean habitat worldwide, though some populations face pressure from introduced predators and fishing bycatch.
Shearwater: common questions
Why is the shearwater named for shearing?
A shearwater flies with a distinctive stiff-winged glide, banking close to the surface of the water in a way that makes it appear to shear directly through the tops of wave troughs, a flight style efficient enough to cover vast distances of open ocean with minimal energy expenditure.
How does a shearwater find food across such a huge area of ocean?
A shearwater relies on an unusually well-developed sense of smell to detect scattered food sources across vast stretches of open ocean, a sensory adaptation uncommon among birds generally but shared among its tubenose relatives, allowing it to locate productive feeding areas from considerable distances.
Why does a shearwater only visit its nest burrow at night?
A shearwater typically visits its breeding colony only under cover of darkness, since the burrow-nesting adults are especially vulnerable to aerial predators such as gulls and skuas while moving on land, and the cover of night substantially reduces that risk during the vulnerable trips to and from the nest.
How far can a shearwater migrate in a year?
Certain shearwater species undertake extraordinarily long annual migrations, travelling tens of thousands of kilometres in a looping route across entire ocean basins each year, among the longest annual journeys documented for any bird.