Tubenoses | Procellariiformes

Stormvogelachtigen | Petreles y pardelas

The nostrils of these seabirds open in horny tubes on top of the bill, which is itself built up of several separate horny plates. The sense of smell is unusually well developed: food is found by scent far out at sea, and in the dark so is the bird's own nest site. A gland above the eyes strains the salt out of the seawater they take in; the fluid runs down the nasal tubes to the bill tip and is shaken off, so that outside the breeding season these birds need not come ashore. On long, narrow wings they sail low over the waves, carried by the wind pushed up against the surface of the water, with few wingbeats. They breed in colonies on islands and steep coasts, laying one egg a year that both parents incubate in turn; they do not begin breeding until several years old and can live for decades.

Families in this order

Albatrosses | Diomedeidae4 speciesA tendon-and-ligament arrangement in the shoulder locks the wing in the outstretched position, so that hours of gliding cost almost no muscular effort. In a flat calm the birds can barely get off the water and simply sit and wait; taking off needs a run across the surface into the wind. Unlike the other families in the order, the two nostril tubes do not lie side by side on top of the bill but open separately on either side of its base. The heavy bill ends in a sharp hook that seizes squid, fish and floating carrion from the surface, mostly at night when the squid rise; behind fishing boats the birds squabble noisily over offal. Courtship is a long-rehearsed dance of bill-clapping, bowing, sky-pointing and wing-spreading, which over the years a pair grinds down to its own fixed sequence. The chick sits alone on the nest for months while its parents forage thousands of kilometres away, receiving a large helping of stomach oil at each visit, in which swallowed fragments of plastic regularly arrive as well.
Southern storm petrels | Oceanitidae2 speciesThe legs are so long that in flight they project beyond the short, square tail — the clearest difference from the northern family, whose feet stay within the tail. The wings are short and rounded at the tip, and the flight is fluttering and irregular, low over the water, without the shearing arcs of the other tubenoses. While feeding, the bird hangs almost motionless into the wind with its wings raised in a V and patters over the surface with both feet, pushing off with its toes to stay in place among the waves; the prey is mainly small crustaceans, taken near feeding whales and along the edge of the continental shelf. Breeding takes place in the southern summer, on islands around Antarctica and in the southern oceans, in crevices under boulders. Outside that season the birds move north across the equator, so that here they turn up off the coast in midsummer: not as breeders, but as visitors between two breeding seasons.
Northern storm petrels | Hydrobatidae10 speciesFood is picked from the surface while the bird flutters just above it and taps the water with its feet, wings held up and body almost still; small crustaceans, tiny fish and droplets of oil are taken this way. The nostrils sit in a tube on top of the bill, and the sense of smell is so well developed that an oil slick at sea is found from far off and the bird locates its own burrow in the dark by scent. Breeding takes place on uninhabited islands, in a self-dug tunnel or a rock crevice, with one white egg; if a parent stays away longer to feed, that egg can lie cold for several days without being lost. The chick is fed an energy-rich stomach oil and at its heaviest weighs more than an adult. The colony is visited only after dark, to avoid gulls; from the burrows comes a steady purring and chattering. A bird handled at the nest will spray that stomach oil at the intruder.
Petrels, shearwaters and diving petrels | Procellariidae29 speciesBoth nostrils open into a single tube on top of the bill. The flight is distinctive: just above the sea the bird rises at an angle on the wind and then glides back down into the trough on stiff wings, so that the dark upperside and the pale underside flash by turns; the rhythm of those arcs differs between species and at a distance is often the only thing to go on. Food is snatched from the surface in flight or picked up while swimming, and some species row down with half-folded wings tens of metres deep after fish and squid. Carcasses and waste from fishing boats draw large groups that squabble noisily over them. Off the colony the birds gather towards evening in floating rafts on the water; they breed in a self-dug burrow or a rock crevice, and young birds leave for the sea alone at night, on inhabited islands easily disoriented by artificial light. Outside the breeding season many species range across whole ocean basins and cross the equator, so that birds from southern breeding grounds lie off these coasts in midsummer.