Yellow-eyed penguin | |
---|---|
At Curio Bay, Southland District, New Zealand | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Sphenisciformes |
Family: | Spheniscidae |
Genus: | Megadyptes |
Species: | M. antipodes |
Binomial name | |
Megadyptes antipodes | |
Subspecies | |
Megadyptes antipodes antipodes Contents | |
Distribution of yellow-eyed penguin |
The yellow-eyed penguin (Megadyptes antipodes), known also as hoiho, is a species of penguin endemic to New Zealand. [2] [3] It is the sole extant species in the genus Megadyptes.
Previously thought closely related to the little penguin (Eudyptula minor), molecular research has shown it more closely related to penguins of the genus Eudyptes . Like most penguins, it is mainly piscivorous.
The species breeds along the eastern and south-eastern coastlines of the South Island of New Zealand, as well as Stewart Island / Rakiura, Auckland Islands, and Campbell Islands. Colonies on the Otago Peninsula are a popular tourist venue, where visitors may closely observe penguins from hides, trenches, or tunnels.
On the New Zealand mainland, the species has experienced a significant decline over the past 20 years. On the Otago Peninsula, numbers have dropped by 75% since the mid-1990s and population trends indicate the possibility of local extinction in the next 20 to 40 years. While the effect of rising ocean temperatures is still being studied, an infectious outbreak in the mid-2000s played a large role in the drop. Human activities at sea (fisheries, pollution) may have an equal if not greater influence on the species' downward trend. [4]
The yellow-eyed penguin was first described by Jacques Bernard Hombron and Honoré Jacquinot in 1841.
The yellow-eyed penguin is the sole species in the genus Megadyptes. It was previously thought closely related to the little penguin but new molecular research has shown it is more closely related to penguins of the genus Eudyptes . Mitochondrial and nuclear DNA evidence suggests it split from the ancestors of Eudyptes around 15 million years ago. In 2019 the 1.25Gb genome of the species was published as part of the Penguin Genome Consortium, [5] [6] and this will help resolve the origins and aid conservation by helping to inform any future breeding programmes.
The yellow-eyed penguin (M. a. antipodes) is most easily identified by the band of pale yellow feathers surrounding its eyes and encircling the back of its head. [19] Its forehead, crown and the sides of its face are slate grey flecked with golden yellow. [20] Its eye is yellow. [2] [19] The foreneck and sides of the head are light brown. [2] The back and tail are slate blue-black. [2] [20] Its chest, stomach, thighs and the underside of its flippers are white in colour. [2] Juvenile birds have a greyer head with no yellow band around their eyes. [19]
It is the largest living penguin to breed on the mainland of New Zealand and the fourth or fifth heaviest living penguin by body mass. [2] [21] It stands 62–79 centimetres (24–31 in) tall and weighs 3–8.5 kilograms (6.6–18.7 lb). [2] [22] Weight varies throughout the year, with penguins being heaviest just before moulting, during which they may lose 3–4 kilograms in weight. [23] Males at around 5.53 kg (12.2 lb) on average are somewhat heavier than females at an average of 5.13 kg (11.3 lb). [21] [22] [24]
The yellow-eyed penguin may be long lived, with some individuals reaching 20 years of age. Males are generally longer lived than females, leading to a sex ratio of 2:1 around the age of 10–12 years. [25]
The yellow-eyed penguin is mostly silent. [2] It makes a shrill bray-like call at nest and breeding sites. [3]
Until recently, it was assumed that M. a. antipodes was widespread and abundant before the arrival of Polynesian settlers in New Zealand. However, genetic analysis has since revealed that its range only expanded to include mainland New Zealand in the past 200 years. Yellow-eyed penguins expanded out of the subantarctic to replace New Zealand's endemic Waitaha penguin (M. waitaha). The Waitaha penguin became extinct between about 1300 and 1500, soon after Polynesian settlers arrived in New Zealand. [13] [26] Jeremy Austin, a member of the team that discovered the Waitaha penguin, said, "Our findings demonstrate that yellow-eyed penguins on mainland New Zealand are not a declining remnant of a previous abundant population, but came from the subantarctic relatively recently and replaced the extinct Waitaha penguin." [27]
A dwarf subspecies from the Chatham Islands, M. a. richdalei, is extinct. [16] The modern population of yellow-eyed penguins does not breed on the Chatham Islands.
Today, yellow-eyed penguins are found in two distinct populations. [28] The northern population extends along the southeast coast of the South Island of New Zealand, down to Stewart Island / Rakiura and Codfish Island / Whenua Hou. [2] It includes four main breeding areas in Banks Peninsula, North Otago, Otago Peninsula and the Catlins. It is also referred to as the mainland population. [3] The southern population includes the subantarctic Auckland Islands and Campbell Island / Motu Ihupuku. [28] There is little gene flow between the northern and southern populations as the large stretch of ocean between the South Island and subantarctic region and the subtropical convergence act as a natural barrier. [29] Based on monitoring between 2012-2017, there are on average 577 breeding pairs per year on Enderby Island in the Auckland Islands, which comprise 37-49% of the total breeding population for the species. [30]
Whether yellow-eyed penguins are colonial nesters has been an ongoing point of debate among zoologists in New Zealand. Most Antarctic penguin species nest in large, high density aggregations of birds; in contrast, yellow-eyed penguins do not nest within sight of each other. While they can be seen coming ashore in groups of four to six or more individuals, they then disperse along tracks to individual nest sites up to one kilometre inland. [31] [32] Accordingly, the consensus among New Zealand penguin workers is to use habitat rather than colony to refer to areas where yellow-eyed penguins nest.
First breeding occurs at three to four years of age and long-term partnerships are formed. Nest sites are selected in August and normally two eggs are laid in September. The incubation duties (lasting 39–51 days) are shared by both parents, who may spend several days on the nest at a time. For the first six weeks after hatching, the chicks are guarded during the day by one parent while the other is at sea feeding. The foraging adult returns at least daily to feed the chicks and relieve the partner. After the chicks are six weeks of age, both parents go to sea to supply food to their rapidly growing offspring. Chicks usually fledge in mid-February and are totally independent from then on. Chick fledge weights are generally between 5 and 6 kg.
Around 90% of the yellow-eyed penguin's diet is made up of fish, chiefly demersal species that live near the seafloor, including silversides (Argentina elongata), blue cod (Parapercis colias), red cod (Pseudophycis bachus), and opalfish (Hemerocoetes monopterygius). [33] [34] Other species taken are New Zealand blueback sprat (Sprattus antipodum) and cephalopods such as arrow squid ( Nototodarus sloanii ). They also eat some crustaceans, including krill ( Nyctiphanes australis). Recently, jellyfish were found to be targeted by the penguins. While initially thought that the birds would prey on jellyfish itself, [35] deployments of camera loggers revealed that the penguins were going after juvenile fish and fish larvae associated with jellyfish. [36]
Breeding penguins usually undertake two kinds of foraging trips: day trips where the birds leave at dawn and return in the evening ranging up to 25 km from their colonies, and shorter evening trips during which the birds are seldom away from their nest longer than four hours or range farther than 7 km. [37] Yellow-eyed penguins are known to be an almost exclusive benthic forager that searches for prey along the seafloor. Accordingly, up to 90% of their dives are benthic dives. [37] This also means that their average dive depths are determined by the water depths within their home ranges, [38] but can swim up to 240 meters below the water surface. [39]
The yellow-eyed penguin is considered one of the rarest penguin species in the world. [40] It is listed on the IUCN Red List as being endangered. It was first included on the list in 1988 when it was listed as threatened. Its status has since been changed to endangered in the year 2000. [41]
It had an estimated population of 4000 in 2007. The main threats include habitat degradation and introduced predators. It may be the most ancient of all living penguins. [42]
A reserve protecting more than 10% of the mainland population was established at Long Point in the Catlins in November 2007 by the Department of Conservation and the Yellow-eyed Penguin Trust. [43] [44]
In August 2010, the yellow-eyed penguin was granted protection under the U.S. Endangered Species Act. [45]
In spring 2004, a previously undescribed disease killed off 60% of yellow-eyed penguin chicks on the Otago Peninsula and in North Otago. The disease has been linked to an infection of Corynebacterium , a genus of bacteria that also causes diphtheria in humans. It has been described as diphtheritic stomatitis and the pathogen identified. [46] A similar problem has affected the Stewart Island population. [47] Treatment of chicks in hospital has proven successful with 88% of 41 chicks treated in 2022 surviving. [48]
Several mainland habitats have hides and are relatively accessible for those wishing to watch the birds come ashore. These include beaches at Oamaru, the Moeraki lighthouse, a number of beaches near Dunedin, and the Catlins. In addition, commercial tourist operations on Otago Peninsula also provide hides to view yellow-eyed penguins. However, the yellow-eyed penguin cannot be found in zoos because it will not reproduce in captivity. [49]
The little penguin is a species of penguin from New Zealand. They are commonly known as fairy penguins, little blue penguins, or blue penguins, owing to their slate-blue plumage and are also known by their Māori name kororā. They are fossorial birds.
The Auckland Islands are an archipelago of New Zealand, lying 465 km (289 mi) south of the South Island. The main Auckland Island, occupying 460 km2 (180 sq mi), is surrounded by smaller Adams Island, Enderby Island, Disappointment Island, Ewing Island, Rose Island, Dundas Island, and Green Island, with a combined area of 570 km2 (220 sq mi). The islands have no permanent human inhabitants.
The Otago Peninsula is a long, hilly indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the eroded valley that now forms Otago Harbour. The peninsula lies south-east of Otago Harbour and runs parallel to the mainland for 20 km, with a maximum width of 9 km. It is joined to the mainland at the south-west end by a narrow isthmus about 1.5 km wide.
The erect-crested penguin is a penguin endemic to the New Zealand region and only breeds on the Bounty and Antipodes Islands. It has black upper parts, white underparts and a yellow eye stripe and crest. It spends the winter at sea and little is known about its biology and breeding habits. Populations are believed to have declined during the last few decades of the twentieth century, and the International Union for Conservation of Nature has listed it as being "endangered".
The Snares penguin, also known as the Snares crested penguin and the Snares Islands penguin, is a penguin from New Zealand. The species breeds on the Snares Islands, a group of islands off the southern coast of the South Island. It is a yellow-crested penguin, with a size of 50–70 cm (19.5–27.5 in) and a weight of 2.5–4 kg (5.5–8.8 lb). It has dark blue-black upper parts and white underparts. It has a bright yellow eyebrow-stripe which extends over the eye to form a drooping, bushy crest. It has bare pink skin at the base of its large red-brown bill.
The Fiordland penguin, also known as the Fiordlandcrested penguin, is a crested penguin species endemic to New Zealand. It currently breeds along the south-western coasts of New Zealand's South Island as well as on Stewart Island/Rakiura and its outlying islands. Because it originally ranged beyond Fiordland, it is sometimes referred to as the New Zealand crested penguin. It is occasionally found in Australia.
Eudyptes is a genus of penguins whose members are collectively called crested penguins. The exact number of species in the genus varies between four and seven depending on the authority, and a Chatham Islands species became extinct in recent centuries. All are black and white penguins with yellow crests, red bills and eyes, and are found on Subantarctic islands in the world's southern oceans. All lay two eggs, but raise only one young per breeding season; the first egg laid is substantially smaller than the second.
Campbell Island / Motu Ihupuku is an uninhabited subantarctic island of New Zealand, and the main island of the Campbell Island group. It covers 112.68 square kilometres (43.51 sq mi) of the group's 113.31 km2 (43.75 sq mi), and is surrounded by numerous stacks, rocks and islets like Dent Island, Folly Island, Isle de Jeanette-Marie, and Jacquemart Island, the latter being the southernmost extremity of New Zealand. The island is mountainous, rising to over 500 metres (1,640 ft) in the south. A long fiord, Perseverance Harbour, nearly bisects it, opening out to sea on the east coast.
The Antipodes Islands are inhospitable and uninhabited volcanic islands in subantarctic waters to the south of – and territorially part of – New Zealand. The 21 km2 (8.1 sq mi) archipelago lies 860 km (530 mi) to the southeast of Stewart Island / Rakiura, and 730 km (450 mi) to the northeast of Campbell Island. They are very close to being the antipodal point of Normandy in France: the city farthest away is Cherbourg-en-Cotentin.
The stitchbird or hihi is a honeyeater-like bird endemic to the North Island and adjacent offshore islands of New Zealand. Its evolutionary relationships have long puzzled ornithologists, but it is now classed as the only member of its own family, the Notiomystidae. It is rare, being extirpated everywhere except Little Barrier Island, but has been reintroduced to two other island sanctuaries and four locations on the North Island mainland. Current population estimations for mature individuals in the wild are 2,500–3,400.
The Campbell Islands are a group of subantarctic islands, belonging to New Zealand. They lie about 600 km south of Stewart Island. The islands have a total area of 113 km2 (44 sq mi), consisting of one big island, Campbell Island, and several small islets, notably Dent Island, Isle de Jeanette Marie, Folly Island, Jacquemart Island, and Monowai Island. Ecologically, they are part of the Antipodes Subantarctic Islands tundra ecoregion. The islands are one of five subantarctic island groups collectively designated as a World Heritage Site by UNESCO.
The Subantarctic snipe is a species of snipe endemic to New Zealand's subantarctic islands. The Maori call it "Tutukiwi". The nominate race C. a. aucklandica is found on the Auckland Islands. Other subspecies include C. a. meinertzhagenae from the Antipodes Islands, and C. a. perseverance from Campbell Island / Motu Ihupuku. The former subspecies from the Snares Islands has been separated as a full species, the Snares snipe, as have the extinct South Island and North Island snipes.
The austral snipes, also known as the New Zealand snipes or tutukiwi, are a genus, Coenocorypha, of tiny birds in the sandpiper family, which are now only found on New Zealand's outlying islands. There are currently three living species and six known extinct species, with the Subantarctic snipe having three subspecies, including the Campbell Island snipe discovered as recently as 1997. The genus was once distributed from Fiji, New Caledonia and Norfolk Island, across New Zealand and southwards into New Zealand's subantarctic islands, but predation by introduced species, especially rats, has drastically reduced their range.
The Bounty shag, also known as the Bounty Island shag, is a species of cormorant of the family Phalacrocoracidae. They are found only on the tiny and remote Subantarctic Bounty Islands, 670 km (420 mi) southeast of New Zealand. Its natural habitats are open seas and rocky shores. In 2022, a full Unmanned aerial vehicle survey of the Bounty archipelago found a total of 573 breeding pairs and estimates the population to consist of approximately 1,733 birds. These recent estimates are consistent with the only other comparable study from 1978 and suggest that the species' population has remained stable over the past 45 years.
The eastern rockhopper penguin, also known as the tawaki piki toka, is a crested penguin with yellow crest feathers. It is a subspecies of the southern rockhopper penguin found in subantarctic regions and the Indian Ocean. It is one of the smallest crested penguins and has distinctive pink margins around its bill.
The Snares snipe, also known as the Snares Island snipe, or tutukiwi in Māori, is a species of bird in the sandpiper family, Scolopacidae.
Waitaha may refer to:
Yolanda van Heezik is a New Zealand academic and a professor of zoology at the University of Otago. She is considered one of New Zealand's first urban ecologists.