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
Crested (duck breed) with and 50% without a crest. Crested (duck breed) The Crested is a breed of domestic duck. It was probably brought to Europe from the East Indies by Dutch ships. It has its appearance because it is heterozygous for a genetic mutation causing a deformity of the skull. The Crested probably originates in the East Indies, with subsequent development in Holland. Crested ducks are seen in seventeenth-century paintings such as those of Melchior d'Hondecoeter and Jan Steen. Paintings as old as 2000 years have depicted images of a bird, resembling a duck with an assortment of feathers on top of