SHEARWATERS, PETRELS, AND FULMARS: Procellariidae

PHYSICAL CHARACTERISTICS

Procellariids (members of the family Procellariidae) have hooked bills that assist them in handling slippery food. The tubular (tube-shaped) nostrils are credited with the birds' well-developed sense of smell used for locating food from far away as well as nests in the dark.

These birds range from 9.1 to 11 inches (23 to 28 centimeters) to 31.9 to 39 inches (81 to 99 centimeters), depending on the species. Wingspans measure about 6.6 feet (2 meters). Procellariids are covered in white, blue, gray, brown, and black feathers. Unlike other wildlife, coloration does not vary by sex or season.

Because their legs are rather weak, procellariids are generally awkward on land. They do not actually walk, but rather shuffle on their breasts and wings. The exception to this is the giant petrel, whose legs are strong.

GEOGRAPHIC RANGE

Procellariids live on oceans throughout the world, in the Northern and Southern Hemispheres.

HABITAT

Procellariids live almost exclusively on the ocean, coming to shore only to breed.

DIET

These nocturnal, active at night, birds eat squid, plankton, and marine life that has been discarded from fishing vessels. Giant petrels also eat seal and penguin carcasses.

BEHAVIOR AND REPRODUCTION

Procellariids excel at flying, with equal ability to flap as well as soar, which makes finding and catching food easy. Shearwaters are named for their tendency to glide just over the water's surface.

Like other Procellariiformes, procellariids vomit their smelly stomach oil onto enemies. This defense mechanism is used against predators during breeding season and against humans who get too close.

Procellariids breed in locations near seawater. Although many species gather together to form breeding colonies, others breed alone or in much smaller colonies. Their nests are made of mounds of grass and stones or in the crevices of rock ledges, depending on the location and what building material is available. Still other nesters burrow into the ground or use abandoned rabbit dens as home for their egg.

At the time of its first breeding the procellariid is usually around five or six years old. One egg is laid, and both parents take turns sitting on it in shifts lasting two to fourteen days. This goes on for six to nine weeks, depending on the species, and then the egg hatches. Parents care for the chick but leave it as soon as it is able to control its own body temperature, which is anywhere from two to twenty days after birth. At that time, parents visit the chick only at feeding time. A week or two after the parents leave, the chick heads out to sea.

These birds live for an average of fifteen to twenty years, though one is on record as living to the age of fifty.

FREQUENT FLYER MILES

Manx shearwaters migrate over 6,210 miles (10,000 kilometers) every winter on their way to South America. This is an amazing fact in and of itself, but consider how far the oldest known wild bird has flown. A Manx shearwater was tagged in Northern Ireland and identified as an adult (at least five years old) in 1953. It was trapped again in July 2003, making it at least fifty-five years old. Given that this Manx makes an annual migration of 6,210 miles, which means it has flown a minimum of 621,000 miles (1,000,000 kilometers) in its lifetime (fifty roundtrip flights of 12,420 miles [19,984 kilometers]).

SHEARWATERS, PETRELS, AND FULMARS AND PEOPLE

Procellariid eggs and meat are eaten by people in a number of cultures, including Eskimos and Europeans. Every year several thousand chicks are harvested for their feathers, fat, flesh, oil, and down in New Zealand and Tasmania.

CONSERVATION STATUS

Some procellariid populations are thriving, but others are among the most threatened birds in the world. Forty-seven procellariids are on the World Conservation Union's (IUCN) List of Threatened Species. All are Threatened, facing a high to extremely high risk of extinction, or Near Threatened, in danger of becoming threatened. These species are considered threatened because of habitat deterioration as well as introduced, brought in by humans, predators.

MANX SHEARWATER (Puffinus puffinus): SPECIES ACCOUNTS

Physical characteristics: Manx shearwaters weigh anywhere from 12.3 to 20.3 ounces (350 to 575 grams) and are 11.8 to 15 inches (30 to 38 centimeters) long. Their wingspan is 29.9 to 35 inches (76 to 89 centimeters). The upper body is black with white underneath.

Geographic range: Manx shearwaters breed mostly on the coastal cliffs around the North Atlantic Ocean, with a large population in Britain and Ireland. They spend the winter months off the coast of Brazil, Argentina, and Uruguay.

Habitat: Manx shearwaters burrow on offshore islands and coastal hills.

Diet: They eat mostly squid, crustaceans, and shoaling fish, small fish that travel in large schools.

Behavior and reproduction: Manx shearwaters glide along the ocean's waves and are known to dive and swim near the surface to feed. Breeding colonies can include hundreds of thousands of pairs of birds who gather at night, with the breeding season beginning in March. Although silent on the water, the calling of the birds at the breeding site is near deafening.

One egg is laid in mid-May and incubates, warmed by parents, for forty-seven to fifty-five days. Chicks fly on their own after sixty-two to seventy-six days. First breeding occurs at five or six years of age.

Manx shearwaters and people: The Manx shearwater used to be hunted for food, but today is basically left alone.

Conservation status: The Manx shearwater is not threatened. ∎

NORTHERN FULMAR (Fulmarus glacialis): SPECIES ACCOUNTS

Physical characteristics: One of the larger shearwaters, the northern fulmar is about 18 inches (46 centimeters) long, with a wingspan of 40.2 to 44.1 inches (102 to 112 centimeters). Northern fulmars resemble gulls, with gray upper bodies and white heads. However, their wings are broader, and the neck is thicker. Their bill is yellow.

Geographic range: Northern fulmars live in the northern Atlantic and Pacific Oceans. They breed in the Aleutian Islands of Alaska.

Habitat: Northern fulmars prefer the colder water of the Northern Hemisphere.

Diet: They feed on fish, squid, shrimp, plankton, and scraps tossed off of fishing boats. If this food is scarce, the northern fulmar will scavenge, eat, carrion, dead, rotting flesh.

Behavior and reproduction: Northern fulmars are more aggressive in their use of vomiting as a defense mechanism than are other procellariids. Although commonly confused with gulls, their flying patterns make them easy to distinguish. Northern fulmars hold their stiff wings straight out from their bodies after several quick wing beats, allowing them to glide rather than fly.

Breeding season begins in May, and nests are actually shallow, bowl-like depressions lined with vegetation. In some areas, the birds lay their eggs on bare rocks. A single egg is laid each year. Incubation lasts forty-seven to fifty-three days, and the parents care for the chick for the first two weeks. Chicks take their first solo flights around the age of forty-six to fifty-three days.

Northern fulmars and people: Although it was once hunted for food, the northern fulmar now has limited human interaction. It comes into contact with humans only on the occasions when it follows fishing vessels in search of food.

Conservation status: These birds are not threatened, although their populations have declined with the advent of modern fish processing methods now used at sea. The innovation has reduced the amount of "waste" food thrown overboard. ∎

FOR MORE INFORMATION

Books:

Servenly, Vincent. Flight of the Shearwater. Kenthurst, Australia: Kangaroo Press, 1997.

Warham, John. Petrels: Their Ecology and Breeding Systems. London and San Diego: Academic Press, 1990.

Web sites:

"Birds of Nova Scotia: Northern Fulmar." Nova Scotia Museum of Natural History. http://museum.gov.ns.ca/mnh/nature/nsbirds/bns0011.htm (accessed on May 14, 2004).

"Manx Shearwater." BBC. http://www.bbc.co.uk/nature/wildfacts/factfiles/831.shtml (accessed on May 14, 2004).

"Manx Shearwater." eNature.com. http://www.enature.com/fieldguide/showSpeciesSH.asp?curGroupID=1&shapeID=957&curPageNum=16&recnum=BD0666 (accessed on May 14, 2004).

"Northern Fulmar." eNature.com. http://www.enature.com/fieldguide/showSpeciesIMG.asp?imageID=17710 (accessed on May 14, 2004).

"Shearwaters." NSW National Parks and Wildlife Service. http://www.nationalparks.nsw.gov.au/npws.nsf/Content/Shearwaters (accessed on May 14, 2004).