The Fiordland penguin (Eudyptes pachyrhynchus), also called the Fiordland crested penguin, is a type of crested penguin found only in New Zealand. In the Māori language, it is called tawaki or pokotiwha. This penguin breeds along the southwestern coasts of New Zealand’s South Island, as well as on Stewart Island/Rakiura and its smaller nearby islands. It used to live in areas beyond Fiordland, which is why it is sometimes called the New Zealand crested penguin. It is sometimes found in Australia.

Taxonomy

The Fiordland crested penguin was first described in 1845 by English zoologist George Robert Gray. The penguin's scientific name comes from Ancient Greek words: "pachy-" meaning "thick" and "rhynchos" meaning "beak." This penguin is one of four to seven species in the group called Eudyptes. The name Eudyptes is also from Ancient Greek, with "eu" meaning "good" and "dyptes" meaning "diver."

Description

This species is a medium-sized penguin with a yellow crest on its head and black-and-white feathers. It grows to about 55 cm (22 in) long and weighs around 3.5 kg (7.7 lb), with a weight range of 2 to 5 kg (4.4 to 11.0 lb). Its face has white markings, and the front of its body is white, while the head and body are black. A broad, yellow crest starts at the base of the beak, covers the eye, and extends down the neck. It can be told apart from the similar erect-crested penguin (Eudyptes sclateri) and Snares penguin (Eudyptes robustus) because it has no bare skin near the base of its bill. Female Fiordland penguins lay two eggs, with the first egg being much smaller than the second. The first egg usually hatches later and has a higher chance of not surviving, a pattern called a brood reduction system that is unique among birds. The Fiordland crested penguin has greater breeding success than most other Eudyptes species, except for the southern rockhopper penguin, even in areas with both introduced and native predators.

Distribution and habitat

This penguin builds nests in groups near tree roots and rocks in thick coastal forests. It lays eggs along the shores of the West Coast of the South Island, south of Bruce Bay and the Open Bay Islands, near Fiordland and Foveaux Strait, and on Stewart Island/Rakiura and its surrounding islands. Fossils of this penguin have been found as far north as the northern tip of the South Island, and it likely lived in the North Island in the past. Its living area was greatly reduced due to hunting during Polynesian times, and today it only lives in the least-populated regions of New Zealand. This species was also found in Australia.

Behaviour

The main prey species reported are cephalopods, which make up 85% of their diet, mainly arrow squid (Nototodarus sloanii). Crustaceans, such as krill (Nyctiphanes australis), account for 13% of their prey, and fish, including red cod and Blue grenadier (hoki), make up 2%. However, the role of cephalopods in their diet might be overestimated. The types of prey they eat differ between Codfish Island and northern Fiordland.

Eudyptes pachyrhynchus are divided into three groups based on their location in the fjord and where they hunt: inner-fjord, mid-fjord, and outer-fjord. Outer-fjord penguins dive deeper and faster than mid-fjord penguins, which hunt in the upper 20 meters of the water. In isolated populations, the availability of local food and resources from outside the area affects their survival and colony health.

When researchers search for nests, penguins may temporarily leave their nests, increasing the risk of predation if searches occur during the first half of the incubation period. Domestic dogs are a major threat to the species. Conservation efforts encourage people to keep dogs leashed near penguin habitats to protect them.

The reproductive and incubation habits of Fiordland crested penguins are not well studied, but they offer important insights into their life cycles and breeding success. Breeding behaviors influence their feeding habits and interactions with other penguins. Outside of breeding and incubation, these penguins usually travel alone and are active at night.

Fiordland crested penguins become sexually mature at about 5 to 6 years old and begin breeding. After spending four months at sea, they form small groups in winter and breed from July to December, staying on land for about 20 weeks before the chick leaves. Breeding occurs when food is most available to support their energy needs. During courtship, they display by showing off their flippers and crests and making loud barks and braying sounds, different from the short, high-pitched calls used for communication. Hormone levels, such as oestradiol in females and testosterone in males, rise during courtship but drop after eggs are laid. Progesterone remains high during and after egg-laying. Each nest has two eggs, with the second egg being larger.

Fiordland crested penguins build nests in small, scattered groups on steep slopes covered by rainforests and on open coastal areas like Jackson Head. Staying at the same nesting site helps improve breeding success, and both males and females show similar loyalty to their nests. Though they are often considered monogamous, failure to raise a chick can lead to separation. The incubation period lasts 31 to 36 days, with both parents taking turns guarding the eggs. The male guards the nest for three weeks while the female feeds the chick. If breeding fails, males are more likely to return to a previous nest site, though they still show higher nest loyalty than other penguin species. Heavy rain and storms increase chick deaths, and the larger egg often survives, leading to higher mortality for the smaller chick due to starvation.

The first egg laid by Fiordland crested penguins is more likely to die than the second egg, even though there is no evidence of aggression or overcrowding. Most deaths occur during the egg-laying period, and the first egg hatches later than the second, even though it is smaller. Once the chick is about 21 to 28 days old, it joins a group of chicks and is fed by both parents until it leaves for the sea at around 75 days old. Adults molt once a year, usually in their nests after 60 to 80 days at sea, and fast for about 25 days while growing new feathers. During the time when eggs are being formed, less nutrients are passed to the eggs compared to body reserves. The first yolk develops for several days before the second yolk begins to grow. During chick rearing, penguins use central-place foraging strategies, staying close to nesting areas while hunting for food.

In captivity, such as at Melbourne Zoo, Fiordland crested penguins spend less time preening or interacting with their environment and instead focus on swimming or using nests. After breeding, they travel southwest and split into two groups: some head toward the subtropical front in late November, while others go to the sub-Antarctic front in December. Penguins traveling to the sub-Antarctic front are more affected by sea level, currents, and water depth, while those heading to the subtropical front are more influenced by sea surface temperature and chlorophyll a levels.

Conservation

Fiordland crested penguins are considered near threatened by the IUCN. Their status was changed from vulnerable to endangered by the Department of Conservation in 2013. Surveys in the 1990s found about 2,500 pairs, but this number might have been too low. Based on past trends, the population is likely decreasing. The main threats include introduced predators like dogs, cats, rats, and especially stoats. They are also at risk from human activity, which causes them to leave their nests, leaving their chicks unprotected from predators.