Macaroni Penguin
Encyclopedia
The Macaroni Penguin is a species of penguin
found from the Subantarctic
to the Antarctic Peninsula
. One of six species of crested penguin, it is very closely related to the Royal Penguin
, and some authorities consider the two to be a single species. It bears a distinctive yellow crest, and the face and upperparts are black and sharply delineated from the white underparts. Adults weigh on average 5.5 kg (12 lb) and are 70 cm (28 in) in length. The male and female are similar in appearance although the male is slightly larger with a relatively larger bill. Like all penguins, it is flightless, with a streamlined body and wings stiffened and flattened into flippers for a marine lifestyle.
The diet consists of a variety of crustacean
s, mainly krill
, as well as small fish and cephalopod
s; the species consumes more marine life annually than any other species of seabird. These birds moult
once a year, spending about three to four weeks ashore, before returning to the sea. Numbering up to 100,000 individuals, the breeding colonies of the Macaroni Penguin are among the largest and densest of all penguin species. After spending the summer months breeding, penguins disperse into the oceans for six months; a 2009 study found that Macaroni Penguins from Kerguelen
travelled over 10000 km (6,213.7 mi) in the central Indian Ocean
. With about 18 million individuals, the Macaroni Penguin is the most numerous penguin species. However, widespread decline in populations have been recorded since the mid 1970s. These factors result in their conservation status
being reclassified as vulnerable
.
. It is one of six or so species in the genus Eudyptes, collectively known as crested penguins. The genus name is derived from the Ancient Greek
words eu "good", and dyptes "diver". The specific epithet chrysolophus is derived from the Greek words chryse "golden", and lophos "crest".
The common name was recorded from the early 19th century in the Falkland Islands. English sailors apparently named the species for its conspicuous yellow crest; Maccaronism was a term for a particular style
in 18th-century England marked by flamboyant or excessive ornamentation. A person who adopted this fashion was labelled a maccaroni or macaroni, as in the song "'Yankee Doodle
".
Mitochondrial and nuclear
DNA
evidence suggests that the Macaroni Penguin split from its closest relative, the Royal Penguin
(Eudyptes schlegeli), around 1.5 million years ago. Although the two have generally been considered separate species, the close similarities of their DNA sequences has led some, such as the Australian ornithologists Les Christidis and Walter Boles, to treat the Royal as a subspecies of the Macaroni. The two species are very similar in appearance, although the Royal Penguin has a white face instead of the usually black face of the Macaroni. Interbreeding with the Indopacific subspecies of the Southern Rockhopper Penguin
(E. chrysocome filholi) has been reported at Heard and Marion Islands, with three hybrids recorded there by a 1987–88 Australian National Antarctic Research Expedition.
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The Macaroni Penguin is a large, crested penguin, similar in appearance to other members of the genus Eudyptes. An adult bird has an average length of around 70 cm (28 in); the weight varies markedly depending on time of year and sex. Males average from 3.3 kg (7 lb) after incubating, or 3.7 kg (8 lb) post-moult to 6.4 kg (14 lb) pre-moult, while females average 3.2 kg (7 lb) post-moult to 5.7 kg (13 lb) pre-moult. The head, chin, throat and upperparts are black and sharply demarcated against the white underparts. The black plumage
has a bluish sheen when new and brownish when old. The most striking feature is the yellow crest that arises from a patch on the centre of the forehead, and extends horizontally backwards to the nape
. The flippers are blue-black on the upper surface with a white trailing edge, and mainly white underneath with a black tip and leading edge. The large bulbous bill
is orange-brown. The iris
is red and there is a patch of pinkish bare skin from the base of the bill to the eye. The legs and feet are pink. The male and female are similar in appearance, although males tend to be slightly larger. Males also bear relatively larger bills, which average around 6.1 cm (2.4 in) compared to 5.4 cm (2.1 in) in females; this feature has been used to tell the sexes apart.
Immature birds are distinguished by their smaller size, smaller duller brown bill, dark grey chin and throat, and absent or underdeveloped head plumes, often just a scattering of yellow feathers. The crest is fully developed in birds aged 3–4 years, a year or two before breeding age.
Macaroni Penguins moult
once a year, a process in which they replace all of their old feathers. They spend around two weeks accumulating fat before moulting because they do not feed during the moult, as they cannot enter the water to forage for food without feathers. The process typically takes three to four weeks, which they spend sitting ashore. Once finished, they go back to sea and return to their colonies to mate in the spring. Overall survival rates are poorly known; the successful return of breeding adults at South Georgia Island
varied between 49 and 78% over three years, and around 10% of those that did return did not breed the following year.
and Crozet Islands
.
to the Antarctic Peninsula
; at least 216 breeding colonies at 50 sites have been recorded. In South America
, Macaroni Penguins are found in southern Chile
, the Falkland Islands
, South Georgia and the South Sandwich Islands
, and South Orkney Islands
. They also occupy much of Antarctica and the Antarctic Peninsula, including the northern South Shetland Islands
, Bouvet Island
, the Prince Edward and Marion island
s, the Crozet Islands
, the Kerguelen Islands
, the Heard and McDonald Islands. While foraging for food, groups will range north to the islands off Australia
, New Zealand
, southern Brazil
, Tristan da Cunha
, and South Africa
.
Like other penguin species, the Macaroni Penguin is a social animal
in its nesting and its foraging behaviour; its breeding colonies are among the largest and most densely populated of all penguin species. Outside the breeding season, the penguin is pelagic; birds disperse to sea from April or May until October. A 2009 study by a French team led by scientist Charles Andre Bost found that Macaroni Penguins nesting at Kerguelen dispersed eastwards over an area exceeding 3×106 km2. Fitted with geolocation
sensors, the 12 penguins studied travelled over 10000 km (6,213.7 mi) in this period and spent their time largely within a zone 47–49° S and 70–110° E in the central Indian Ocean, not coming ashore once. This area, known as the Polar Frontal Zone
, was notable for the absence of krill.
Living in colonies results in a high level of social interaction between birds, which has led to a large repertoire of visual as well as vocal displays. These behaviours peak early in the breeding period, and colonies particularly quieten when the male Macaroni Penguins are at sea. Agonistic displays are those which are intended to confront or drive off, or alternatively, appease and avoid conflict with other individuals. Macaroni Penguins, particularly those on adjacent nests, may engage in bill-jousting; birds lock bills and wrestle, each trying to unseat the other, as well as batter with flippers and peck or strike their opponent's nape. Submissive displays include the slender walk, where birds move through the colony with feathers flattened, flippers moved to the front of the body, and head and neck hunched, and general hunching of head and neck when incubating or standing at the nest.
s, squid
and fish
, although the proportions that each make up vary with locality and season. Krill
, particularly Antarctic krill
(Euphausia superba), account for over 90% of food during breeding season. Cephalopods and small fish such as the Marbled rockcod
(Notothenia rossii), Painted notie
(Lepidonotothen larseni), Champsocephalus gunneri, the lanternfish
species Krefftichthys anderssoni, Protomyctophum tenisoni and P. normani become more important during chick-rearing. Like several other penguin species, the Macaroni Penguin sometimes deliberately swallows small (10–30 mm diameter) stones; this behaviour has been speculated to aid in providing ballast for deep-sea diving, or to help grind food, especially the exoskeletons of crustaceans that are a significant part of its diet.
Foraging for food is generally conducted on a daily basis, from dawn to dusk when there are chicks to feed. Overnight trips are sometimes made, especially as the chicks grow older; a 2008 study that used surgically implanted data loggers to track the movement of the birds showed the foraging trips become longer once the chick-rearing period is over. Birds venture out for 10–20 days during incubation and before the moult. Macaroni penguins are known to be the largest single consumer of marine resources among all of the seabird
s, with an estimated take of 9.2 million tonne
s of krill a year. Outside the breeding season, Macaroni Penguins tend to dive deeper, longer, and more efficiently during their winter migration than during the summer breeding season. Year round, foraging dives usually occur during daylight hours, but winter dives are more constrained by daylight due to the shorter days.
Foraging distance from colonies has been measured at around 50 km (31 mi) at South Georgia, offshore over the continental shelf, and anywhere from 59 to 303 km (36.7 to 188.3 mi) at Marion Island. Macaroni Penguins normally forage at depths of 15 to 70 m (49.2 to 229.7 ft), but have been recorded diving down to 100 metres (328.1 ft) on occasions. Some night foraging does occur, but these dives are much shallower, ranging from only 3 to 6 m (9.8 to 19.7 ft) in depth. Dives rarely exceed two minutes in duration. All dives are V-shaped, and no time is spent at the sea bottom; about half the time on a foraging trip is spent diving. Birds have been calculated as catching anywhere from 4–16 krill or 40–50 amphipods per dive.
(Hydrurga leptonyx), Antarctic Fur Seal
(Arctocephalus gazella) and Subantarctic Fur Seal
(A. tropicalis) sometimes hunt adult Macaroni Penguins in the water. Colonies suffer low rates of predation if undisturbed; predators generally only take eggs and young that have been left unattended or deserted. Skua
species, the Snowy Sheathbill
(Chionis alba), and Kelp Gull
(Larus dominicanus) prey on eggs, and skuas and Giant Petrel
s also sometimes take chicks.
Adult Macaroni Penguins typically begin to breed late in October, and lay their eggs
in early November. The nest itself is a shallow scrape in the ground which may be lined with some pebbles, stones, or grass, or nestled in a clump of tussock grass
(on South Georgia Island). Nests are densely packed, ranging from around 66 m apart in the middle of a colony to 86 cm at the edges. A fertile Macaroni Penguin will lay two eggs each breeding season. The first egg to be laid weighs 90 –, 61–64% the size of the 145 – second, and is extremely unlikely to survive. The two eggs together weigh 4.8% of the mother's body weight; the composition of an egg is 20% yolk, 66% albumen, and 14% shell. Like those of other penguin species, the shell is relatively thick to minimise risk of breakage, and the yolk is large, which is associated with chicks born in an advanced stage of development. Some of the yolk remains at hatching and is consumed by the chick in its first few days.
The fate of the first egg is mostly unknown, but studies on the related Royal Penguin
and Erect-crested Penguin
show the female tips the egg out when the larger second egg is laid. The task of incubating
the egg is divided into three roughly equal sessions of around 12 days each over a five week period. The first session is shared by both parents, followed by the male returning to sea, leaving the female alone to tend the egg. Upon the male's return, the female goes off to sea and does not return until the chick has hatched. Both sexes fast for a considerable period during breeding; the male fasts for 37 days after arrival until he returns to sea for around ten days before fasting while incubating eggs and young for another 36 days, and the female fasts for 42 days from her arrival after the male until late in the incubation period. Both adults lose 36–40% of their body weight during this period. The second egg hatches around 34 days after it is laid. Macaroni Penguins typically leave their breeding colony by April or May to disperse into the ocean.
From the moment the egg is hatched, the male Macaroni Penguin cares for the newly hatched chick. For about 23 to 25 days the male protects its offspring and helps to keep it warm, since only a few of its feathers have grown in by this time. The female brings food to the chick every one to two days. When they are not being protected by the adult male penguins, the chicks form crèches
to keep warm and stay protected. Once their adult feathers have grown in at about 60–70 days, they are ready to go out to sea on their own.
Penguin
Penguins are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers...
found from the Subantarctic
Subantarctic
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...
to the Antarctic Peninsula
Antarctic Peninsula
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....
. One of six species of crested penguin, it is very closely related to the Royal Penguin
Royal Penguin
The Royal Penguin inhabits the waters surrounding Antarctica. Royals look very much like Macaroni Penguins, but have a white face and chin instead of the Macaronis' black visage. They are long and weigh . Males are larger than females...
, and some authorities consider the two to be a single species. It bears a distinctive yellow crest, and the face and upperparts are black and sharply delineated from the white underparts. Adults weigh on average 5.5 kg (12 lb) and are 70 cm (28 in) in length. The male and female are similar in appearance although the male is slightly larger with a relatively larger bill. Like all penguins, it is flightless, with a streamlined body and wings stiffened and flattened into flippers for a marine lifestyle.
The diet consists of a variety of 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, mainly krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
, as well as small fish and cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s; the species consumes more marine life annually than any other species of seabird. These birds moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
once a year, spending about three to four weeks ashore, before returning to the sea. Numbering up to 100,000 individuals, the breeding colonies of the Macaroni Penguin are among the largest and densest of all penguin species. After spending the summer months breeding, penguins disperse into the oceans for six months; a 2009 study found that Macaroni Penguins from Kerguelen
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
travelled over 10000 km (6,213.7 mi) in the central Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. With about 18 million individuals, the Macaroni Penguin is the most numerous penguin species. However, widespread decline in populations have been recorded since the mid 1970s. These factors result in their conservation status
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
being reclassified 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:...
.
Taxonomy
The Macaroni Penguin was described from the Falkland Islands in 1837 by German naturalist Johann Friedrich von BrandtJohann Friedrich von Brandt
Johann Friedrich von Brandt was a German naturalist.Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg and the University of Berlin. In 1831 he was appointed director of the Zoological Department at the St Petersburg Academy of Sciences, where he published in Russian...
. It is one of six or so species in the genus Eudyptes, collectively known as crested penguins. The genus name is derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
words eu "good", and dyptes "diver". The specific epithet chrysolophus is derived from the Greek words chryse "golden", and lophos "crest".
The common name was recorded from the early 19th century in the Falkland Islands. English sailors apparently named the species for its conspicuous yellow crest; Maccaronism was a term for a particular style
Fashion
Fashion, a general term for a currently popular style or practice, especially in clothing, foot wear, or accessories. Fashion references to anything that is the current trend in look and dress up of a person...
in 18th-century England marked by flamboyant or excessive ornamentation. A person who adopted this fashion was labelled a maccaroni or macaroni, as in the song "'Yankee Doodle
Yankee Doodle
"Yankee Doodle" is a well-known Anglo-American song, the origin of which dates back to the Seven Years' War. It is often sung patriotically in the United States today and is the state anthem of Connecticut...
".
Mitochondrial and nuclear
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
evidence suggests that the Macaroni Penguin split from its closest relative, the Royal Penguin
Royal Penguin
The Royal Penguin inhabits the waters surrounding Antarctica. Royals look very much like Macaroni Penguins, but have a white face and chin instead of the Macaronis' black visage. They are long and weigh . Males are larger than females...
(Eudyptes schlegeli), around 1.5 million years ago. Although the two have generally been considered separate species, the close similarities of their DNA sequences has led some, such as the Australian ornithologists Les Christidis and Walter Boles, to treat the Royal as a subspecies of the Macaroni. The two species are very similar in appearance, although the Royal Penguin has a white face instead of the usually black face of the Macaroni. Interbreeding with the Indopacific subspecies of the Southern Rockhopper Penguin
Southern Rockhopper Penguin
The Southern Rockhopper Penguin group , are two subspecies of rockhopper penguin, that together are sometimes considered distinct from the Northern Rockhopper Penguin...
(E. chrysocome filholi) has been reported at Heard and Marion Islands, with three hybrids recorded there by a 1987–88 Australian National Antarctic Research Expedition.
Description
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
has a bluish sheen when new and brownish when old. The most striking feature is the yellow crest that arises from a patch on the centre of the forehead, and extends horizontally backwards to the nape
Nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is referred to by the word nucha, which also gives the adjective corresponding to "nape" in English, "nuchal"....
. The flippers are blue-black on the upper surface with a white trailing edge, and mainly white underneath with a black tip and leading edge. The large bulbous bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is orange-brown. The iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
is red and there is a patch of pinkish bare skin from the base of the bill to the eye. The legs and feet are pink. The male and female are similar in appearance, although males tend to be slightly larger. Males also bear relatively larger bills, which average around 6.1 cm (2.4 in) compared to 5.4 cm (2.1 in) in females; this feature has been used to tell the sexes apart.
Immature birds are distinguished by their smaller size, smaller duller brown bill, dark grey chin and throat, and absent or underdeveloped head plumes, often just a scattering of yellow feathers. The crest is fully developed in birds aged 3–4 years, a year or two before breeding age.
Macaroni Penguins moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
once a year, a process in which they replace all of their old feathers. They spend around two weeks accumulating fat before moulting because they do not feed during the moult, as they cannot enter the water to forage for food without feathers. The process typically takes three to four weeks, which they spend sitting ashore. Once finished, they go back to sea and return to their colonies to mate in the spring. Overall survival rates are poorly known; the successful return of breeding adults at South Georgia Island
South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands is a British overseas territory and overseas territory of the European Union in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands, known as the South Sandwich...
varied between 49 and 78% over three years, and around 10% of those that did return did not breed the following year.
Vocalisation
The calls of this species are similar to other crested penguins; birds are especially noisy in colonies when establishing territories and forming pairs, and quieten down during incubation. During this period, parents make trumpeting calls when changing shifts at the nest; birds recognise each other more by voice than by location. A penguin calling for its chick or its mate has to compete with the vocalisations of potentially thousands of other birds – an environment with huge background noise and few visual cues. Field studies suggest that Macaroni penguins achieve this communication with the use of a display-call, a complex sound containing a unique acoustic signature for each bird. Calls recorded at colonies on South Georgia have a more rapid rhythm and lower pitch than those on KerguelenKerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
and Crozet Islands
Crozet Islands
The Crozet Islands are a sub-antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands.-Geography:...
.
Distribution and habitat
A 1993 review estimated that the Macaroni was the most abundant species of penguin, with a minimum of 11,841,600 pairs of Macaroni Penguins worldwide. Macaroni Penguins range from the 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...
to the Antarctic Peninsula
Antarctic Peninsula
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica. It extends from a line between Cape Adams and a point on the mainland south of Eklund Islands....
; at least 216 breeding colonies at 50 sites have been recorded. In South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, Macaroni Penguins are found in southern Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, the Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
, South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands is a British overseas territory and overseas territory of the European Union in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands, known as the South Sandwich...
, and South Orkney Islands
South Orkney Islands
The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula. They have a total area of about ....
. They also occupy much of Antarctica and the Antarctic Peninsula, including the northern South Shetland Islands
South Shetland Islands
The South Shetland Islands are a group of Antarctic islands, lying about north of the Antarctic Peninsula, with a total area of . By the Antarctic Treaty of 1959, the Islands' sovereignty is neither recognized nor disputed by the signatories and they are free for use by any signatory for...
, Bouvet Island
Bouvet Island
Bouvet Island is an uninhabited Antarctic volcanic island in the South Atlantic Ocean, 2,525 km south-southwest of South Africa. It is a dependent territory of Norway and, lying north of 60°S latitude, is not subject to the Antarctic Treaty. The centre of the island is an ice-filled crater of an...
, the Prince Edward and Marion island
Prince Edward Islands
The Prince Edward Islands are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. The islands, named Marion Island and Prince Edward Island, are located at ....
s, the Crozet Islands
Crozet Islands
The Crozet Islands are a sub-antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands.-Geography:...
, the Kerguelen Islands
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
, the Heard and McDonald Islands. While foraging for food, groups will range north to the islands off 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...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, southern Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Tristan da Cunha
Tristan da Cunha
Tristan da Cunha is a remote volcanic group of islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying from the nearest land, South Africa, and from South America...
, and South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Conservation
Although the population of Macaroni Penguins is estimated at around 18 million mature individuals, a substantial decline has been recorded in several locations. This includes a 50% reduction in the South Georgia population between the mid 1970s to mid 1990s, and the disappearance of the species from Isla Recalada in Southern Chile. This decline of the overall population in the last 30 years has resulted in the classification of the species as globally Vulnerable by the IUCN Red List of Threatened Species. Long-term monitoring programs are underway at a number of breeding colonies, and many of the islands that support breeding populations of this penguin are protected reserves. The Heard Islands and McDonald Islands are World Heritage Sites for the Macaroni Penguin. The Macaroni Penguin may be being impacted by commercial fishing and marine pollution. A 2008 study suggests that the abilities of female penguins to reproduce may be negatively affected by climate- and fishing-induced reductions in krill density.Behaviour
Social animal
A social animal is a loosely defined term for an organism that is highly interactive with other members of its species to the point of having a recognizable and distinct society.All mammals are social to the extent that mothers and offspring bond...
in its nesting and its foraging behaviour; its breeding colonies are among the largest and most densely populated of all penguin species. Outside the breeding season, the penguin is pelagic; birds disperse to sea from April or May until October. A 2009 study by a French team led by scientist Charles Andre Bost found that Macaroni Penguins nesting at Kerguelen dispersed eastwards over an area exceeding 3×106 km2. Fitted with geolocation
Geolocation
Geolocation is the identification of the real-world geographic location of an object, such as a radar, mobile phone or an Internet-connected computer terminal...
sensors, the 12 penguins studied travelled over 10000 km (6,213.7 mi) in this period and spent their time largely within a zone 47–49° S and 70–110° E in the central Indian Ocean, not coming ashore once. This area, known as the Polar Frontal Zone
Antarctic Convergence
The Antarctic Convergence is a curve continuously encircling Antarctica where cold, northward-flowing Antarctic waters meet the relatively warmer waters of the subantarctic. Antarctic waters predominantly sink beneath subantarctic waters, while associated zones of mixing and upwelling create a zone...
, was notable for the absence of krill.
Living in colonies results in a high level of social interaction between birds, which has led to a large repertoire of visual as well as vocal displays. These behaviours peak early in the breeding period, and colonies particularly quieten when the male Macaroni Penguins are at sea. Agonistic displays are those which are intended to confront or drive off, or alternatively, appease and avoid conflict with other individuals. Macaroni Penguins, particularly those on adjacent nests, may engage in bill-jousting; birds lock bills and wrestle, each trying to unseat the other, as well as batter with flippers and peck or strike their opponent's nape. Submissive displays include the slender walk, where birds move through the colony with feathers flattened, flippers moved to the front of the body, and head and neck hunched, and general hunching of head and neck when incubating or standing at the nest.
Diet
The diet of the Macaroni Penguin consists of a variety of crustaceanCrustacean
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, squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
and 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...
, although the proportions that each make up vary with locality and season. Krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
, particularly Antarctic krill
Antarctic krill
Antarctic krill, Euphausia superba, is a species of krill found in the Antarctic waters of the Southern Ocean. It is a shrimp-like crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre...
(Euphausia superba), account for over 90% of food during breeding season. Cephalopods and small fish such as the Marbled rockcod
Marbled rockcod
The marbled rockcod, Notothenia rossii, is a marine cod icefish in the family Nototheniidae with distribution ranging from southern New Zealand to sub-Antarctic seas, on rocky reefs...
(Notothenia rossii), Painted notie
Painted notie
The painted notie, Lepidonotothen larseni , is a marine cod icefish in the family Nototheniidae with distribution in the Southern Ocean, ranging east from southern South America to south of the central Indian Ocean. Their length is up to 24 cm....
(Lepidonotothen larseni), Champsocephalus gunneri, the lanternfish
Lanternfish
Cooper Lanternfishes are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represented by 246 species in 33 genera, and are found in oceans worldwide. They are aptly named after their conspicuous use of bioluminescence...
species Krefftichthys anderssoni, Protomyctophum tenisoni and P. normani become more important during chick-rearing. Like several other penguin species, the Macaroni Penguin sometimes deliberately swallows small (10–30 mm diameter) stones; this behaviour has been speculated to aid in providing ballast for deep-sea diving, or to help grind food, especially the exoskeletons of crustaceans that are a significant part of its diet.
Foraging for food is generally conducted on a daily basis, from dawn to dusk when there are chicks to feed. Overnight trips are sometimes made, especially as the chicks grow older; a 2008 study that used surgically implanted data loggers to track the movement of the birds showed the foraging trips become longer once the chick-rearing period is over. Birds venture out for 10–20 days during incubation and before the moult. Macaroni penguins are known to be the largest single consumer of marine resources among all of the seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s, with an estimated take of 9.2 million tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s of krill a year. Outside the breeding season, Macaroni Penguins tend to dive deeper, longer, and more efficiently during their winter migration than during the summer breeding season. Year round, foraging dives usually occur during daylight hours, but winter dives are more constrained by daylight due to the shorter days.
Foraging distance from colonies has been measured at around 50 km (31 mi) at South Georgia, offshore over the continental shelf, and anywhere from 59 to 303 km (36.7 to 188.3 mi) at Marion Island. Macaroni Penguins normally forage at depths of 15 to 70 m (49.2 to 229.7 ft), but have been recorded diving down to 100 metres (328.1 ft) on occasions. Some night foraging does occur, but these dives are much shallower, ranging from only 3 to 6 m (9.8 to 19.7 ft) in depth. Dives rarely exceed two minutes in duration. All dives are V-shaped, and no time is spent at the sea bottom; about half the time on a foraging trip is spent diving. Birds have been calculated as catching anywhere from 4–16 krill or 40–50 amphipods per dive.
Predators
The Macaroni Penguin's predators consist of birds and aquatic mammals. The Leopard SealLeopard Seal
The leopard seal , also referred to as the sea leopard, is the second largest species of seal in the Antarctic...
(Hydrurga leptonyx), Antarctic Fur Seal
Antarctic Fur Seal
The Antarctic fur seal is one of eight seals in the genus Arctocephalus, and one of nine fur seals in the subfamily Arctocephalinae. As its name suggests, the Antarctic fur seal is distributed in Antarctic waters. Around 95% of the world population breeds at the Island of South Georgia...
(Arctocephalus gazella) and Subantarctic Fur Seal
Subantarctic Fur Seal
The subantarctic fur seal is a fur seal found in the southern parts of the Indian and Atlantic Oceans. It was first described by Gray in 1872 from a specimen recovered in northern Australia—hence the inappropriate tropicalis specific name.- Description :The subantarctic fur seal is...
(A. tropicalis) sometimes hunt adult Macaroni Penguins in the water. Colonies suffer low rates of predation if undisturbed; predators generally only take eggs and young that have been left unattended or deserted. Skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
species, the Snowy Sheathbill
Snowy Sheathbill
The Snowy Sheathbill also known as a Pale-faced sheathbill or Paddy is one of two species of sheathbill. It is usually found on the ground. It is Antarctica's only permanently land-based bird.- Description :...
(Chionis alba), and Kelp Gull
Kelp Gull
The Kelp Gull , also known as the Dominican Gull, breeds on coasts and islands through much of the southern hemisphere. The race L. d. vetula occurs around southern Africa, and nominate L. d...
(Larus dominicanus) prey on eggs, and skuas and Giant Petrel
Giant petrel
Giant petrels is a genus, Macronectes, from the family Procellariidae and consist of two species. They are the largest birds from this family...
s also sometimes take chicks.
Courtship and breeding
Female Macaroni Penguins can begin breeding at around five years of age, while the males do not normally breed until at least six years old. Females breed at a younger age because the male population is larger. The surplus of male penguins allows the female penguins to select more experienced male partners as soon as the females are physically able to breed. Commencing a few days after females arrive to the colony, sexual displays are used by males to attract partners and advertise their territory, and by pairs once together at the nest site and at changeover of incubation shifts. In the ecstatic display, a penguin bows forward, making loud throbbing sounds, and then extends its head and neck up until the neck and beak are vertical. The bird then waves its head from side to side braying loudly. Birds also engage in mutual bowing, trumpeting, and preening. Monitoring of pair fidelity at South Georgia has shown around three quarters of pairs will breed together again the following year.Adult Macaroni Penguins typically begin to breed late in October, and lay their eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
in early November. The nest itself is a shallow scrape in the ground which may be lined with some pebbles, stones, or grass, or nestled in a clump of tussock grass
Tussock (grass)
Tussock grasses or bunch grasses are found as native plants in natural ecosystems, as forage in pastures, and as ornamental grasses in gardens....
(on South Georgia Island). Nests are densely packed, ranging from around 66 m apart in the middle of a colony to 86 cm at the edges. A fertile Macaroni Penguin will lay two eggs each breeding season. The first egg to be laid weighs 90 –, 61–64% the size of the 145 – second, and is extremely unlikely to survive. The two eggs together weigh 4.8% of the mother's body weight; the composition of an egg is 20% yolk, 66% albumen, and 14% shell. Like those of other penguin species, the shell is relatively thick to minimise risk of breakage, and the yolk is large, which is associated with chicks born in an advanced stage of development. Some of the yolk remains at hatching and is consumed by the chick in its first few days.
The fate of the first egg is mostly unknown, but studies on the related Royal Penguin
Royal Penguin
The Royal Penguin inhabits the waters surrounding Antarctica. Royals look very much like Macaroni Penguins, but have a white face and chin instead of the Macaronis' black visage. They are long and weigh . Males are larger than females...
and Erect-crested Penguin
Erect-crested Penguin
The Erect-crested Penguin is a penguin from New Zealand. It breeds on the Bounty and Antipodes Islands.This is a small-to-medium-sized, yellow-crested, black-and-white penguin, at and weighing . As in all penguin species, the male is slightly larger than the female and the birds weigh the most...
show the female tips the egg out when the larger second egg is laid. The task of incubating
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
the egg is divided into three roughly equal sessions of around 12 days each over a five week period. The first session is shared by both parents, followed by the male returning to sea, leaving the female alone to tend the egg. Upon the male's return, the female goes off to sea and does not return until the chick has hatched. Both sexes fast for a considerable period during breeding; the male fasts for 37 days after arrival until he returns to sea for around ten days before fasting while incubating eggs and young for another 36 days, and the female fasts for 42 days from her arrival after the male until late in the incubation period. Both adults lose 36–40% of their body weight during this period. The second egg hatches around 34 days after it is laid. Macaroni Penguins typically leave their breeding colony by April or May to disperse into the ocean.
From the moment the egg is hatched, the male Macaroni Penguin cares for the newly hatched chick. For about 23 to 25 days the male protects its offspring and helps to keep it warm, since only a few of its feathers have grown in by this time. The female brings food to the chick every one to two days. When they are not being protected by the adult male penguins, the chicks form crèches
Crèche (zoology)
The Crèche in zoology refers to care of another's offspring, for instance in a colony. This term is used in the study of bird colonies...
to keep warm and stay protected. Once their adult feathers have grown in at about 60–70 days, they are ready to go out to sea on their own.