Penguins, Predators and Prey is a series of stamp issues featuring, in turn, each of the familiar Falkland penguins, together with some of their respective predators and prey.
This issue features the Rockhopper Penguin and includes one predatory species, the Johnny Rook, and one prey species, the Lobster Krill.
There are three recognized races of Rockhopper. E. c. chrysocome breeds in the Falklands and islands off Tierra del Fuego. E.c.moseleyi breeds on Tristan da Cunha, Gough, St Paul and Amsterdam Islands. E.c.filholi breeds on islands in the southern Indian Ocean and also on islands to the south of New Zealand.
The “Southern” Rockhopper E. c. chrysocome is the smallest but most numerous of the Falkland penguins. Charmingly referred to as “Jumping Jacks” by S.W.Clayton on Saunders Island in 1774, they were first described for science by J R Forster in 1781. Early voyagers to the islands soon discovered the nutritious and lasting qualities of their eggs. American sealer, Edmund Fanning, described how he pickled Rockhopper eggs on New Island in 1797, by soaking them in seal oil and burying them in barrels filled with sand. During the mid-19th century, hundreds of thousands of birds were rounded up into primitive stone corrals, then clubbed and rendered down for oil. One bird was said to yield about a pint, which in turn was used to light the streets of London.
30p Johnny Rook Phalcoboenus australis
The “Johnny Rook” (proper name Striated Caracara) is a coastal predator and scavenger. The greater part of the world's population resides permanently in the Falklands. There are probably in excess of 1000 pairs island-wide. Most of the birds live on offshore islands or on West Falkland. There are also a few other populations, mainly on islands, in the regions to the south and south-west of Tierra del Fuego.
“Rooks” were immediately noticed by early settlers and visitors to the Falklands due to their extraordinary lack of fear of humans. They soon acquired the name of “Johnny Rook” which has remained with them to this day. “Johnny” referred to the Gentoo Penguin near which they are found throughout the year. “Rook” derives from their similar size and social habits to those of the English Rook Corvus frugilegus.
During the summer months “rooks” are usually found close to seal or seabird colonies. In the winter, with most of the seabirds away at sea, they become more widely distributed and their diet broadens to include beetles and grubs raked up from the soil with their talons. They will eat any kind of meat or fish they can find or catch, dead or alive and will even take meat from your hand.
Their nest is generally made of sticks and grass and situated in tussac, on shallow cliffs, or under a slab of rock. Between late October and early November, they lay 2-4, creamy-coloured eggs blotched with brick red. They can be very aggressive and noisome when guarding young in the nest.
75p Rockhopper Penguins Eudyptes chrysocome chrysocome performing “mutual” display
Southern Rockhoppers usually breed in cliff top colonies situated close to and above a traditional rocky landing beach. Colonies can be comprised of tens of thousands of birds and are often mixed in with those of shags and albatross. Individuals may have to walk up to a quarter mile to reach their own nest site. Rockhoppers lay 2 eggs but, on average, rear only one chick. Their breeding season extends between October and March.
The spring sound of a Rockhopper colony is loud, raucous and distinctive. Arthur Cobb, farming on Bleaker Island in the 1920's, described the sound of a colony as being “as if thousands of wheelbarrows, all badly in need of greasing, are being pushed at full speed.”
Courtship generally begins, in early spring, with both visual and auditory displays. Once paired off, male and female penguins perform “the mutual display” together. This display seems to strengthen the pair bond. Heads and necks are stretched upward or forward with heads swinging to the accompaniment of much loud braying. Rockhoppers stand facing each other, performing the action in unison. Mutual displays continue throughout the breeding season, often taking place at the nest when parents switch places for egg incubation and chick feeding.
£1 Rockhopper Penguin Eudyptes chrysocome chrysocome
Rockhoppers are deep ocean seabirds which return to land only to breed and to moult. Between April and early October they live an entirely pelagic existence. They are able to dive in excess of 150 metres in pursuit of their prey which consists mainly of krill and lobster krill. Typically, however, their dives are much shallower and the average depth is closer to 50 metres.
The Rockhopper Penguin is one of five modern species in the genus Eudyptes (derived from the ancient Greek meaning “good diver”). Along with the Macaroni Eudyptes chrysolophus, it is one of the two Eudyptids which breed in the Falkland archipelago. There are, perhaps, between 400,000 and 700,000 breeding pairs island wide, although numbers vary quite markedly in cycles as with many seabirds. They reach an average height of 52cm, weigh about 3 kilos and may live for up to ten years in the wild.
Birds lose both weight and condition during the stressful period of chick rearing. So at the end of the breeding season they return to the sea to fatten up before returning to their colonies in March/April to moult. During an approximately 3 week period they replace all of their feathers with a new set before returning to the ocean for the winter.
£1.20 Lobster Krill Munida gregaria
Lobster Krill is one of many crustaceans commonly referred to as squat lobsters which are among the most abundant and diverse ten-legged marine “decapods” worldwide. It is very abundant in coastal waters around the Falkland Islands and southern South America, and also off eastern New Zealand and its sub-Antarctic islands. This small reddish crab has a total length up to 76mm. The males are slightly larger than the females.
They appear first as larvae in midwinter, and subsequently pass through 5 larval stages until post larval metamorphosis in spring. The pelagic post larvae shoal over summer, during which time adult features are wholly or partly acquired. During the late summer months they form dense congregations near the surface and close to the shore. Afterwards they settle to the bottom where they may live for 2 to 3 years and spawn up to 3 times.
Lobster Krill plays an important role in the trophic web of the sub-Antarctic coastal ecosystem. Evidence of its importance as a food species to Rockhopper Penguins is shown by the brick red stain in their excreta around the nest sites.
The design for the 75p stamp was based on a photograph by Kim Chater.
Text by Tony Chater
Artist: Tony Chater
Printer: BDT International
Process: Stochastic Lithography
Perforation: 14 per 2cms
Stamp size: 30.56 x 38mm
Sheet Layout: 50 (2 x 25)
Release date: 28 March 2013Production Co-ordination: Creative Direction (Worldwide) Ltd