Ancient Murrelet
Encyclopedia
The Ancient Murrelet, Synthliboramphus antiquus, is a bird
in the auk
family. It breeds from the Yellow Sea (islands off China), through the Russian Pacific coast and the Aleutian Islands to the Haida Gwaii archipelago of British Columbia, where about half of the world population breeds.
These birds breed in colonies
, their two eggs (sometimes one) are laid in burrows excavated in forest soil among tree roots, under logs or in grass tussocks, occasionally in rock crevices. These small auks arrive at and depart from their nesting grounds at night, presumably to reduce predation, and perhaps for the same reason the young are never fed at the nest, being taken to sea 1-3 days after hatching. The parents and young recognise one another by call and after the chicks have run from the burrow to the sea, they locate their parents by call and the entire family swims immediately out at sea. The family continues to move away from land for at least twelve hours. After that, the young are fed exclusively at sea by their parents for more than a month.
Some Ancient Murrelets move
south in winter as far as California
, and odd birds are found inland in North America, carried by autumn storms. The most remarkable record of this relatively short-distance Pacific migrant was a bird found on Lundy
, Devon
in spring 1990. Even more remarkably, the same bird returned to this British
island the following spring.
This small auk species is black on the head, throat and rear neck, grey-backed, and has white underparts. The yellow bill is short and stubby. It has a small rounded black tail. The summer adults have white head streaks giving an aged look and leading to the English
name. Other plumages are similar, but lack the crown streaks and black on the throat.
Ancient Murrelets tend to bank from side to side in flight to a greater extent than other small auks. They fly with fast wing beats due to their short wings. Like other auks, Ancient Murrelets forage by swimming underwater using their wings for propulsion. Their diet is poorly known. In winter it consists mainly of crustacea, while in summer both small fish
, and crustacean
s are taken. Based on stable isotope
analysis, their diet in Haida Gwaii seems to consist primarily of small mesopelagic
fish.
The Ancient Murrelet is listed as of 'Special Concern' by the Committee on the Status of Endangered Wildlife in Canada because populations have been greatly reduced over the past century by mammalian predators introduced to their breeding islands. Some recent restoration work is helping to reverse this trend.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the auk
Auk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...
family. It breeds from the Yellow Sea (islands off China), through the Russian Pacific coast and the Aleutian Islands to the Haida Gwaii archipelago of British Columbia, where about half of the world population breeds.
These birds breed in colonies
Bird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...
, their two eggs (sometimes one) are laid in burrows excavated in forest soil among tree roots, under logs or in grass tussocks, occasionally in rock crevices. These small auks arrive at and depart from their nesting grounds at night, presumably to reduce predation, and perhaps for the same reason the young are never fed at the nest, being taken to sea 1-3 days after hatching. The parents and young recognise one another by call and after the chicks have run from the burrow to the sea, they locate their parents by call and the entire family swims immediately out at sea. The family continues to move away from land for at least twelve hours. After that, the young are fed exclusively at sea by their parents for more than a month.
Some Ancient Murrelets move
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
south in winter as far as California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, and odd birds are found inland in North America, carried by autumn storms. The most remarkable record of this relatively short-distance Pacific migrant was a bird found on Lundy
Lundy
Lundy is the largest island in the Bristol Channel, lying off the coast of Devon, England, approximately one third of the distance across the channel between England and Wales. It measures about at its widest. Lundy gives its name to a British sea area and is one of the islands of England.As of...
, Devon
Devon
Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
in spring 1990. Even more remarkably, the same bird returned to this British
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
island the following spring.
This small auk species is black on the head, throat and rear neck, grey-backed, and has white underparts. The yellow bill is short and stubby. It has a small rounded black tail. The summer adults have white head streaks giving an aged look and leading to the English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...
name. Other plumages are similar, but lack the crown streaks and black on the throat.
Ancient Murrelets tend to bank from side to side in flight to a greater extent than other small auks. They fly with fast wing beats due to their short wings. Like other auks, Ancient Murrelets forage by swimming underwater using their wings for propulsion. Their diet is poorly known. In winter it consists mainly of crustacea, while in summer both small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, and crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s are taken. Based on stable isotope
Stable isotope
Stable isotopes are chemical isotopes that may or may not be radioactive, but if radioactive, have half-lives too long to be measured.Only 90 nuclides from the first 40 elements are energetically stable to any kind of decay save proton decay, in theory...
analysis, their diet in Haida Gwaii seems to consist primarily of small mesopelagic
Mesopelagic
The mesopelagic is that part of the pelagic zone that extends from a depth of 200 to 1000 metres below the ocean surface. It lies between the photic epipelagic above and the aphotic bathypelagic below, where there is no light at all...
fish.
The Ancient Murrelet is listed as of 'Special Concern' by the Committee on the Status of Endangered Wildlife in Canada because populations have been greatly reduced over the past century by mammalian predators introduced to their breeding islands. Some recent restoration work is helping to reverse this trend.
External links
Database entry includes justification for why this species is of least concern- "National Geographic" Field Guide to the Birds of North America ISBN 0-7922-6877-6
- Seabirds, an Identification Guide by Peter Harrison, (1983) ISBN 0-7470-1410-8
- Handbook of the Birds of the World Vol 3, Josep del Hoyo editor, ISBN 84-87334-20-2
- "National Audubon Society" The Sibley Guide to Birds, by David Allen Sibley, ISBN 0-679-45122-6
- "The Ancient Murrelet" by Anthony J. Gaston (1992) ISBN 978-0-85661070-7