About Eudyptes chrysolophus (Brandt, 1837)
Taxonomy and Appearance Overview
The macaroni penguin (Eudyptes chrysolophus) is a large crested penguin, sharing a similar appearance with other members of the genus Eudyptes.
Length
Adult macaroni penguins have an average length of around 70 cm (28 in).
Weight Variation Factors
Their weight varies noticeably based on season and sex.
Male Weight
After incubation, males average 3.3 kg (7 lb); after moult, they average 3.7 kg (8 lb), and they reach up to 6.4 kg (14 lb) before moult.
Female Weight
For females, weight ranges from an average of 3.2 kg (7 lb) after incubation or moult to 5.7 kg (13 lb) before moult.
Bill Measurements
Among standard body measurements, the thick bill measured from the gape is 7 to 8 cm (2.8 to 3.1 in), while the culmen is approximately one centimeter shorter.
Wing and Tail Measurements
The wing, measured from shoulder to tip, averages around 20.4 cm (8.0 in), and the tail is 9–10 cm (3.5–3.9 in) long.
Body Plumage Base Coloration
The head, chin, throat, and upper body are black, with a sharp border separating these areas from the white underparts. Fresh black plumage has a bluish sheen, while older black plumage becomes brownish.
Distinctive Crest Feature
The species' most distinctive feature is a yellow crest that starts from a patch on the center of the forehead and extends horizontally backward to the nape.
Flipper Coloration
The upper surface of the flippers is blue-black with a white trailing edge; the underside is mostly white, with a black tip and black leading edge.
Bill Color
The large, bulbous bill is orange-brown.
Eye and Facial Skin Features
The iris is red, and a patch of pinkish bare skin extends from the base of the bill to the eye.
Leg and Foot Color
The legs and feet are pink.
Sexual Dimorphism in Size and Bill
Males and females have similar plumage, but males are usually slightly larger, and have relatively larger bills on average: male bills average around 6.1 cm (2.4 in), compared to 5.4 cm (2.1 in) for females.
Sex Identification Method
This bill size difference is commonly used to distinguish between the sexes.
Immature Bird Characteristics
Immature macaroni penguins can be identified by their smaller overall size, smaller duller-brown bills, dark grey chin and throat, and absent or underdeveloped head plumes, which often only appear as a scattering of yellow feathers.
Crest Development Timeline
The crest becomes fully developed when birds are three to four years old, which is one to two years before they reach breeding age.
Moulting Frequency
Macaroni penguins moult once a year, replacing all of their old feathers during this process.
Pre-Moult Fat Storage
They spend around two weeks building up fat stores before moulting, because they cannot feed during the moult—they cannot enter the water to forage without intact feathers.
Moulting Duration and Location
The moult process typically takes three to four weeks, which the penguins spend resting on shore.
Post-Moult Behavior
Once moulting is complete, they return to the sea, and come back to their colonies to mate in the spring.
Survival Rate Knowledge Gap
Overall species-wide survival rates are not well understood.
South Georgia Survival and Breeding Data
Over three years of study, the successful return rate of breeding adult macaroni penguins at South Georgia Island ranged between 49% and 78%, and around 10% of the penguins that did return did not breed in the following year.
Global Population Estimate
A 1993 review estimated that the macaroni penguin is the most abundant penguin species, with a minimum of 11,841,600 breeding pairs worldwide.
General Range
Macaroni penguins have a range extending from the Subantarctic region to the Antarctic Peninsula.
Breeding Colony Count
At least 216 breeding colonies across 50 sites have been recorded.
South America Distribution
In South America, macaroni penguins are found in southern Chile, the Falkland Islands, South Georgia and the South Sandwich Islands, and the South Orkney Islands.
Antarctic Region Distribution
They also occupy much of Antarctica and the Antarctic Peninsula, including the northern South Shetland Islands, Bouvet Island, the Prince Edward and Marion islands, the Crozet Islands, the Kerguelen Islands, and the Heard and McDonald Islands.
Foraging Range Extent
While foraging for food, groups will range as far north as the islands off the coasts of Australia, New Zealand, southern Brazil, Tristan da Cunha, and South Africa.