Macquarie Shag
Encyclopedia
The Macquarie Shag Macquarie Island Shag or Macquarie Island Cormorant, is a marine cormorant
native to Macquarie Island
in the Southern Ocean
, about halfway between Australia
and Antarctica.
s, sometimes placed in the genera
Leucocarbo or Notocarbo, and a subspecies
of the Imperial Shag
. It is sometimes considered to be a full species.
Macquarie Island and the nearby Bishop and Clerk Islets
, part of the Macquarie group, 33 km to the south. Apart from breeding and roosting, its habitat is marine.
s above the base of the bill in front of the eyes, orange-brown facial skin at the base of the lower mandible, as well as blue eye-rings. It is about 75 cm in length, with a wingspan
of 110 cm and a weight of 2.5–3.5 kg.
. Nest-building takes place from June. Nests are truncated cones, 20–30 cm in height, built of vegetation, guano
and mud. The clutch of 2-3 eggs is laid between mid September to January, mainly in late September and early November, with most eggs hatching by late December. Most chicks are independent of their parents by mid February.
fish
. Flocks may feed together.
The taxon is listed as vulnerable
under Australia's Environment Protection and Biodiversity Conservation Act 1999
, because the population is small, localised and subject to fluctuations in breeding success due to weather conditions and food availability. Other threats include predation of nestlings by Subantarctic Skuas and Black Rat
s.
Cormorant
The bird family Phalacrocoracidae is represented by some 40 species of cormorants and shags. Several different classifications of the family have been proposed recently, and the number of genera is disputed.- Names :...
native to Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
in the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
, about halfway between Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and Antarctica.
Taxonomy
The Macquarie Shag is one of the blue-eyed shagBlue-eyed shag
The blue-eyed shags are a group of closely related cormorant taxa. All have a blue, purple or red ring around the eye ; other shared features are white underparts and pink feet....
s, sometimes placed in the genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Leucocarbo or Notocarbo, and a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Imperial Shag
Imperial Shag
The Imperial Shag, Phalacrocorax atriceps, is a black and white cormorant native to many subantarctic islands, the Antarctic Peninsula and southern South America, primarily in rocky coastal regions, but locally also at large inland lakes. It is sometimes placed in the genus Leucocarbo instead...
. It is sometimes considered to be a full species.
Distribution and habitat
The Macquarie Shag is restricted to subantarcticSubantarctic
The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and...
Macquarie Island and the nearby Bishop and Clerk Islets
Bishop and Clerk Islets
The Bishop and Clerk Islets lie approximately to the south of Macquarie Island. They are in area. The Bishop and Clerk Islets mark the southernmost point of Australia . These islets are mostly barren rock less than high and are geologically similar to Macquarie Island.Macquarie Shags have...
, part of the Macquarie group, 33 km to the south. Apart from breeding and roosting, its habitat is marine.
Description
The Macquarie Shag has largely black upperparts and white underparts. The upper cheeks and ear-coverts are black; there are white bars on the wings, a black, recurved crest over the forehead, and pink feet. A breeding adult has a pair of orange caruncleCaruncle
Caruncle may refer to:*In botany, an elaiosome , especially in the plant family Euphorbiaceae*In animal anatomy:**prostomium, the sensory organ of Annelid worms...
s above the base of the bill in front of the eyes, orange-brown facial skin at the base of the lower mandible, as well as blue eye-rings. It is about 75 cm in length, with a wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...
of 110 cm and a weight of 2.5–3.5 kg.
Behaviour
Macquarie Shags are gregarious, roosting in groups of from a few birds up to several hundred.Breeding
The birds are present all year round at Macquarie Island, where they breed annually in small to large colonies on bare rocky shores and stacksStack (geology)
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in the...
. Nest-building takes place from June. Nests are truncated cones, 20–30 cm in height, built of vegetation, guano
Guano
Guano is the excrement of seabirds, cave dwelling bats, and seals. Guano manure is an effective fertilizer due to its high levels of phosphorus and nitrogen and also its lack of odor. It was an important source of nitrates for gunpowder...
and mud. The clutch of 2-3 eggs is laid between mid September to January, mainly in late September and early November, with most eggs hatching by late December. Most chicks are independent of their parents by mid February.
Feeding
The birds forage locally in shallow coastal waters, with the diet consisting primarily of benthicBenthic zone
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...
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...
. Flocks may feed together.
Status and conservation
The Macquarie Shag population was estimated in 2000 to comprise about 760 breeding pairs, including 100 pairs at the Bishop and Clerk Islets. A later (October 2003) survey found 472 nesting pairs in eleven colonies on Macquarie Island itself, indicating a 30% decline.The taxon is listed as vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
under Australia's Environment Protection and Biodiversity Conservation Act 1999
Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
, because the population is small, localised and subject to fluctuations in breeding success due to weather conditions and food availability. Other threats include predation of nestlings by Subantarctic Skuas and Black Rat
Black Rat
The black rat is a common long-tailed rodent of the genus Rattus in the subfamily Murinae . The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe by the 1st century and spreading with Europeans across the world.-Taxonomy:The black rat was...
s.