Royal Penguin

Royal penguins are the largest of the crested penguins, and are endemic to Macquarie Island, an Australian-administered subantarctic island south-west of New Zealand. They are easily recognised by their white faces, massive orange bills, and scruffy orange-yellow crests that meet on the forehead. Royal penguins are rare vagrants to New Zealand, but have occurred as far north as Napier.

Royal penguins are large crested penguins, approaching the size of yellow-eyed or gentoo penguins. They differ from all other crested penguins in that most birds have white faces (sometimes pale grey or dark gray). They are closely related to the (dark-faced) macaroni penguin, and share their enormous orange bill, prominent pink skin at the bill base, and scruffy orange-yellow crests that meet on the forehead. This last character is contra all other crested penguins, which have two separate crests that do not meet on the forehead. The remaining upperparts are blue-black, and the underparts silky white. Immature birds have a less robust, darker bill and reduced crest, but always have some chrome yellow feathers on the forehead.

Like most penguins, royal penguins only come to land when required to breed or moult. They breed at Macquarie Island only, and are rarely recorded on land away from there. Colonies on Macquarie Island are situated on the coast and on slopes up to 200 m. Like other crested penguins, very noisy at colonies. The main call is a deep, throbbing bray or trumpeting. The contact call is a short bark.

Population: The total population of royal penguins is estimated at around 850,000 pairs, with the 57 colonies ranging in size from 60 to more than 160,000 pairs. Vagrant birds are occasionally recorded on New Zealand subantarctic islands, the New Zealand mainland (mainly Otago), Tasmania, South Australia, the Ross Sea sector of Antarctica, and South Georgia. Threats and conservation: Being confined to a single breeding site, royal penguins are vulnerable to single-site catastrophes such as oil-spills. The population is considered stable at about 850,000 pairs in 57 colonies.

Royal penguins breed only on Macquarie Island in large colonies. They arrive in September and lay in October-November. Like all crested penguins, they lay two eggs of markedly different size, with a second larger egg laid about 4 days after the first. As with the two other large crested penguins (macaroni and erect-crested penguins), the egg size dimorphism is extreme, and almost all the small first eggs are lost early in incubation. Only in about 1% of nests does the first egg produce a chick. The five smaller species of crested penguins have less difference in the size of the two eggs, and generally hatch both eggs, with the chick from the smaller egg usually dying of starvation within 10 days. Incubation by royal penguins is shared and takes about 35 days. Both adults feed the chick, with most chicks fledging in late January, when about 65 days old.

Like most penguins, royal penguins spend most of their lives at sea, coming ashore only to breed and moult. Both during breeding and feeding they are highly social. During the breeding season, foraging trips extend out to 415 km for females and 650 km for males, with durations varying from about 19 days during incubation, down to 5-6 days during chick-rearing. After chicks fledge, adults go to sea for about 36 days, after which they return to their breeding site to moult during February-March, which takes about 4 weeks. Once back at sea after the moult they travel vast distances, up to 10,000 km. The main predators of royal penguins are leopard seals, fur seals and sometimes orcas. Predation rates in the colonies are relatively low, with some unguarded chicks and eggs taken by subantarctic skuas (eggs and chicks), southern black backed gulls (eggs only) and giant petrels (chicks only).

Royal penguins feed predominantly on Antarctic krill (Euphausia superba), which make up about 90% of the diet during the breeding season. At other times, fish can make up to 30% of the diet.

References

Bost, C.A.; Thiebot, J.B.; Pinaud, D,; Cherel, Y.; Trathan, P.N. 2009. Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin. Biology Letters 5: 473-476.

Heather, B.D.; Robertson, H.A. 2005. Field guide to the birds of New Zealand. Penguin Group (NZ) Ltd.

Hull, C.L. 1999. Comparison of the diets of breeding royal (Eudyptes schlegeli) and rockhopper (Eudyptes chrysocome) penguins on Macquarie island over three years. Journal of Zoology 247: 507-529.

Hull, C.L. 1999. The foraging zones of breeding royal (Eudyptes schlegeli ) and rockhopper (E. chrysocome) penguins: an assessment of techniques and species comparison. Wildlife Research 26: 789-803.

Hull, C.L.; Wilson, J.; leMar, K. 2001, Moult in adult royal penguins Eudyptes schlegeli. Emu 101: 173-176.

Miskelly, C.M.; Crossland, A.C.; Sagar, P.M.; Saville, I.; Tennyson, A.J.D.; Bell, E.A. 2017. Vagrant and extra-limital records accepted by the Birds New Zealand Records Appraisal Committee 2015-2016. Notornis 64: 57-67.

Shirihai, H. 2007. A complete guide to Antarctic wildlife: the birds and marine mammals of the Antarctic continent and the Southern Ocean. 2nd edn. London: A & C Black.

StClair, C.C.; Waas, J.R.;, StClair, R.C.; Boag, P.T. 1995 Unfit mothers? Maternal infanticide in royal penguins. Animal Behavior 50: 1177-1185.

Williams, TD (1995). The penguins: Spheniscidae. Oxford University Press, Oxford.

SOURCE: New Zealand Birds Online

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