Scientific name: Eudyptes schlegeli
Royal penguins are one of the crested penguins (genus Eudyptes), named for the yellow plumes on their heads; the species name commemorates the German zoologist Hermann Schlegel. Eudyptes means ‘good diver’ and is derived from the Greek (eús) ‘good’ and (dýtis) ‘diver’.
Physical description and related species
Royal penguins are mid-sized penguins. In many ways they look similar to macaroni penguins. However, royals are up to 20% larger than macaronies and also have tend to have white to pale grey faces while macaronis have black faces. The yellow plumes on their heads meet on the forehead. It takes several years for the crests to develop fully. Thus, in young penguins the crests are not as lush as in adults. The sexes are similar but males tend to be somewhat larger than females.
At the start of the breeding season, royals weigh 4.2–6.3kg. During the breeding season, they tend to lose weight. At the end of the guard period, penguins usually weigh only 3–5kg. In preparation for the annual moult they fatten up and lay down body reserves, increasing to up to 8kg.
Distribution and abundance
Royal penguins are endemic to Macquarie Island where the vast majority lives, and the nearby Bishop and Clerk Islets where about 1000 pairs breed. Royals at Macquarie Island live in very large colonies. The largest colony at Hurd Point on Macquarie Island has around 500,000 pairs. Precisely how many royal penguins there are is unknown, but the population is thought to be currently stable. However, due to key populations existing on only 3 islands in close proximity, they are considered have a more critical conservation status.
During the breeding season, royals forage in areas southeast of Macquarie Island where the waters are 4000–5000m deep. They tend to spend time at the northern edge of the Polar Frontal Zone, but the distances they travel and the areas they visit vary throughout the breeding cycle. Partners of incubating birds travel over 600km from Macquarie Island and back again in 3 weeks. After the moult, royals leave the island. It is still unknown where they go during this time, although there have been sightings from Tasmania to the Antarctic sector of the Southern Ocean.
Conservation status: near threatened
The breeding cycle of royal penguins is highly synchronised cycle and starts when the males arrive in late-September to claim nest sites. The females arrive in early October and lay their eggs in mid- to late-October. Incubation lasts about 30 days and chicks start to hatch in early late November/early December. The chick rearing period extends over 2 months. Males guard the chicks for 3 to 4 weeks, until the chicks are large enough to join crèches. From mid-January onward, both parents are free to feed the chick and each adult foraging cycle lasts about 2 days. In late February, the chicks start to fledge and get ready to go to sea. The adults moult in March/April and then leave the island for about 6 months over winter.
Diet and feeding
Royal penguins hunt mainly for two species of krill: Euphausia valentini (≅40% by weight) and some Thysanoessa gregatia (≅10% by weight). The rest of their diet is made up by juvenile lantern fish (myctophids). The proportions change throughout the breeding cycle. The diet differs at colonies around the island, particularly between the east and west coasts and shows substantial annual differences.