Macaroni penguin 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 cm 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 , 61–64% the size of the 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%
Macaroni (horse) entering the straight and held off the sustained challenge of The Oaks winner Queen Bertha to win by one and a half lengths. At Newmarket in October he walked over in the Select Stakes and was then retired to stud. Macaroni was retired to his owner's stud at Hooton until 1866 when was sold for 7,100 guineas to Baron Meyer de Rothschild who moved the stallion to his stud at Mentmore. Macaroni sired several successful racehorses, including the 2000 Guineas winner Macgregor but was more notable as a sire of broodmares. He was the damsire of the Triple Crown winner