Macaroni penguin female are similar in appearance; males tend to be slightly larger. Males also bear relatively larger bills, which average around compared to 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 three to four 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
Macaroni (fashion) of "the Macaroni Club, which is composed of all the traveled young men who wear long curls and spying-glasses". The "club" was not a formal one; the expression was particularly used to characterize fops who dressed in high fashion with tall, powdered wigs with a chapeau bras on top that could only be removed on the point of a sword. The shop of engravers and printsellers Mary and Matthew Darly in the fashionable West End of London sold their sets of satirical "macaroni" caricature prints, published between 1771 and 1773. The new Darly shop became known as "the Macaroni Print-Shop".