Macaroni penguins are easily distinguishable from most other penguins because of their iconic appearance. Sprucing up their black and white regular penguin attire, they feature a yellow crest above their reddish eyes. When 18th century English sailors spotted these penguins, they gave them their iconic name, as they resembled macaronis, young men of the time known for their colorful fashion sense and flamboyant hair-dos. As the largest of the crested penguin species, adults reach a height of around 50 to 70cm (20-28 inches) and a weight of around 6kg (12 pounds). Male macaroni penguins tend to be slightly larger and heavier than females. In comparison to other crested penguins, the feathers in the yellow crest of macaronis meet in the middle of their foreheads, looking just like a colorful unibrow. Little macaroni chicks are grey and white and aren’t born with the signature crest. This article delves into the dietary habits of these fascinating creatures.
Macaroni Penguin Habitat and Distribution
Macaroni penguins live in the Southern Hemisphere and are found around the Antarctic Peninsula, the subantarctic islands (such as South Georgia, South Orkney, South Shetland and the Kerguelen and Falkland Islands), as well as Tierra del Fuego in South America and islands in the Indian Ocean. Nine million breeding pairs are found at over 50 sites, with over 216 colonies worldwide in total. Macaroni penguins prefer rocky coasts and cliffs, as well as tussock grassy areas if available.
Macaroni Penguin Physical Characteristics
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) after moult to 6.4 kg (14 lb) before moult, while females average 3.2 kg (7 lb) after to 5.7 kg (13 lb) before moult. Among standard measurements, the thick bill (from the gape) measures 7 to 8 cm (2.8 to 3.1 in), the culmen being around a centimetre less. The wing, from the shoulder to the tip, is around 20.4 cm (8.0 in) and the tail is 9-10 cm (3.5-3.9 in) long. The head, chin, throat, and upper parts are black and sharply demarcated against the white under parts. 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 a patch of pinkish bare skin is found from the base of the bill to the eye. The legs and feet are pink. 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.
Primary Food Sources
The nutritious krill of the Southern Ocean is the macaroni’s main source of food, supplemented by fish, squid and crustaceans. The diet of the macaroni penguin consists of a variety of crustaceans, squid and fish; the proportions that each makes 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.
Macaroni penguins are carnivores, so they eat marine animals such as krill, small fish, squid, and crustaceans. To eat krill and other sea life with a hard outer shell, macaroni penguins swallow tiny stones to help them grind up the shells to digest them. Other penguins do this as well. A baby macaroni penguin called a chick eats food that’s been mashed up by its mother.
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Dietary Adaptations
Like many other penguin species, macaronis swallow small stones, which is believed to aid with digestion of the hard exoskeletons of crustaceans or to help with diving.
Diving and Foraging Behavior
The macaroni penguin is an amazing diver! While they find most of their prey at a depth of 15 to 70m (49 to 229 ft.), they are able to dive as deep as 100m (330 ft.). Foraging for food is generally conducted on a daily basis, from dawn to dusk when they have 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 normally forage at depths of 15 to 70 m (49 to 230 ft), but have been recorded diving down to 100 m (330 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.
Consumption of Marine Resources
Macaroni penguins are known to be the largest single consumer of marine resources among all of the seabirds, with an estimated take of 9.2 million tonnes of krill a year.
Seasonal Variations in Foraging
Outside the breeding season, macaroni penguins tend to dive deeper, longer, and more efficiently during their winter migration than during the summer breeding season. 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 kilometres (37 to 188 mi) at Marion Island.
Predators and Threats
Look out for killer whales and fur and leopard seals if you’re an adult macaroni penguin. Macaroni penguin chicks and eggs can be prey to hunting sea birds such as petrels and skuas and adult macaroni penguins are vulnerable to orcas (killer whales) and some seal species including the leopard seal, Antarctic fur seal, and Sub-Antarctic fur seal.
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Some surveys studying various breeding populations worldwide suggest a rapid decline in numbers since the 1970s. This led to macaronis’ classification on the IUCN (International Union for Conservation of Nature) Red List as vulnerable. Predators of adult macaroni penguins are fur and leopard seals, as well as killer whales.
Rising sea-surface temperatures as a result of global warming are expected to threaten the macaroni penguin's food supply by causing a decrease in prey abundance and driving prey further away from coastal areas and penguin breeding colonies. Macaroni penguins are also threatened by fisheries interactions and oil pollution.
Conservation Status
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.
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