Huia

When males and females appear as two different species

The pronounced sexual dimorphism between female and male huia caused confusion in the past. This confusion was so significant that, in 1836, the English ornithologist John Gould described male and female huia as different species. Even today, the development of gender-specific beak shapes and lengths is a topic of scientific debate, as no other bird species exhibits such extreme differences. The larger female huia had a long, slender, downward-curved beak, while the smaller males were characterized by a short, strong beak, similar to that of a crow.

Despite the huia’s frequent mention in scientific literature due to its pronounced sexual dimorphism, little is known about its behavior and lifestyle. Before its extinction, there was barely enough time to study the bird species in depth. Much of what we know today about the huia comes from the records of New Zealand ornithologist Walter Buller, who dedicated the latter half of the 19th century to studying this bird intensively.

Like the likely extinct South Island kōkako, the huia belonged to the family Callaeidae, or wattlebirds, which are endemic to the islands of New Zealand. The huia typically had black plumage with a greenish sheen, and its brightly colored orange wattles on either side of the base of its ivory-colored beak were striking and unmistakable. Adult birds also had twelve long black tail feathers with a broad white tip.

Huia – Fact sheet

Scientific name	Heteralocha acutirostris, Neomorpha acutirostris (female), Neomorpha crassirostris (male), Neomorpha gouldi, Heteralocha gouldi
Original range	North Island of New Zealand
Time of extinction	1907 at the earliest
Causes of extinction	habitat loss, hunting, animals introduced to the island and diseases
IUCN status	extinct

The huia preferred primary mixed forests

Subfossil remains and bone deposits indicate that the huia once inhabited both lowland and montane forests on the North Island. Reports collected by Buller, as well as a Māori song called “waiata”, suggest that this species may have also lived in the Marlborough and Nelson districts of the South Island. However, no fossil evidence has yet confirmed its presence there.

Following the settlement of the North Island by the Māori in the 14th century, the huia disappeared from the northern and western parts of the island. By the time Europeans arrived in the 1840s, the bird’s range had shrunk to the Ruahine, Tararua, Rimutaka, and Kaimanawa mountain ranges in the southeastern part of the North Island.

The huia inhabited both of New Zealand’s primary forest types: temperate rainforest and Southern Beech Forest, where it particularly favored mixed forests of Nothofagus and Podocarpus.

Different Beak Shapes as a Feeding Strategy?

Huias, like the extinct North American ivory-billed woodpecker and Cuban ivory-billed woodpecker, fed on insect larvae living in dead wood, as well as berries and seeds. Since New Zealand lacks woodpeckers, the huia and the endangered forest parrot, the kaka (Nestor meridionalis), filled this ecological role.

The huia searched for insect larvae in decaying wood, and scientists believe it specialized in the larvae of the huhu beetle (Prionoplus reticularis), New Zealand’s largest beetle. The bird also fed on other insects such as grasshoppers and spiders.

Initially, Buller and other scientists hypothesized that the differing beak shapes of male and female huia might be linked to their feeding strategies. The theory was that the male, with its short, strong beak, chiselled like a woodpecker to remove bark from rotting wood and expose insect larvae hidden beneath the surface. Meanwhile, the female, with her long, slender beak, was able to probe deep into larval tunnels that were inaccessible to the male, particularly in harder wood that he couldn’t break open.

This theory, put forth by Buller, was based on observations of a captive huia pair being fed larvae. However, modern scientists suggest that the differing beak shapes are more likely an extreme example of niche differentiation, helping to reduce competition for food between males and females. This perspective, championed by biologist Ron J. Moorhouse in The Extraordinary Bill Dimorphism of the Huia: Sexual Selection or Intersexual Competition? (1996), suggests that the species’ beak dimorphism allowed them to exploit a wider range of food sources across different microhabitats.

Ornithologist Philip J. K. Burton, who studied the anatomy of the huia’s head and neck in 1974, found that males and females not only differed in beak shape but also in the structure and musculature of their head and neck. Burton’s research also revealed that the birds had a well-developed jaw musculature, allowing them to open their beaks with considerable force.

Was there a white huia?

The Māori, the indigenous people of New Zealand, referred to certain huia as “huia-ariki“. These birds had brownish plumage with grayish streaks, with darker coloring around the head and neck. Scientists remain divided on whether these were partial albinos or simply very old birds.

There are also reports of completely white huia. Dutch illustrator John G. Keulemans painted one such white bird around 1900. In 2013, ornithologist Julian P. Hume and Hein van Grouw, curator of the ornithological collection at the Natural History Museum in London, investigated the phenomenon in their study Colour Aberrations in Extinct and Endangered Birds.

Since the white huia painted by Keulemans appears to be fully grown, the two scientists ruled out albinism. Instead, they considered progressive graying, leucism, or an ino mutation as the more likely cause of the pale plumage. Another question remains: how could such an unusual bird survive into adulthood? It would likely have been highly sought after by collectors.

Leucism, a congenital defect where the skin lacks pigment cells, resulting in white fur or feathers and pink skin, is extremely rare in wild birds, and thus unlikely to be the cause. In contrast, ino mutations, which are known in species like budgerigars, are not uncommon in wild birds. Hume and Grouw favored this explanation, as freshly molted feathers in inos can appear very pale, almost pure white. Although ino birds have reddish eyes due to the lack of melanin, they do not suffer from the vision problems associated with albinism, allowing them to survive in the wild.

The scientists were unable to locate a pale huia in any ornithological collection, preventing them from confirming the color aberration with certainty. However, the fact that the bird painted by Keulemans was female supports the ino mutation theory. This is because the ino mutation is linked to the Z chromosome, a sex chromosome in birds. Female birds have only one Z chromosome, so if they carry a mutated ino gene, the mutation will be visible. Male birds, on the other hand, have two Z chromosomes, and if only one carries the mutation, the effects may not be visible.

The Māori and the huia

The Māori did not hunt the rare huia for food, but rather for their highly prized feathers, which adorned people of high rank. The bird’s curious nature made it relatively easy for the Māori to catch them. Māori hunters would imitate the bird’s calls to lure them in, capturing them with snares or killing them with clubs or spears.

The Māori also took advantage of the huia’s monogamous nature for their hunting purposes. The birds mated for life, spending their entire existence with the same partner. When one bird was caught, its calls would inevitably attract its mate, which could then be easily captured as well.

Though the bird’s range was not very large, their tail feathers were found in both the far north and deep south of New Zealand, as Māori tribes traded them for valuable goods such as shark teeth. The feathers were used to adorn the heads of the deceased, worn as ornaments at funerals, or used to decorate the homes of chiefs.

The Māori crafted various ornaments from huia. One such adornment, the marereko, was a headpiece made of twelve feathers. The pōhoi, a necklace or earring, was made from dried huia skin, with the bird skinned from the neck, keeping the beak, wattles, and skull intact while removing the legs and wings. Māori also wore dried huia heads as pendants, known as ngutu huia. It was also common to keep the birds in cages, plucking their tail feathers once they had fully grown.

The significance of huia feathers remains evident even today: In April 2024, a single feather fetched a record price of approximately NZ$45,251 at an auction in Auckland, highlighting its ongoing value and rarity. Additionally, for an auction scheduled in London in October 2024, it is expected that a taxidermied huia pair could sell for up to NZ$128,000.

Deforestation took away the huia’s habitat

Although the birds were already rare when Europeans began settling in New Zealand, the large-scale deforestation of the North Island to create farmland for settlers quickly made the birds even scarcer. Huias were particularly sensitive to these environmental changes, as they could only thrive in old-growth forests – forests rich in decaying trees where they found wood-boring insect larvae to feed on. In secondary forests that regenerated after slash-and-burn farming or logging, the birds could not find sufficient food and were unable to survive.

While most of the deforestation occurred in lowland areas, sparing the mountain regions to some extent, the population still suffered a significant decline. Scientists believe that huias relied on lowland forests as winter refuges, where they could escape the snow and extreme cold of the mountain regions. Without access to these critical habitats, their populations plummeted.

Invasive species, exotic diseases, and greedy naturalists

With the arrival of Europeans, various mammal species were introduced to New Zealand. In Die ausgestorbenen Vögel der Welt (1986), Dieter Luther highlights the faunal imbalance caused by European settlement as a major factor in the extinction of species like the huia. Around 35 mammal species were introduced, including dogs, mustelids, rats, cats, rabbits, and deer. The nearly flightless bird, which spent most of its time hopping along the ground or in the lower and mid-levels of trees, was undoubtedly easy prey for these invasive predators.

The IUCN has also posited that the introduction of the common myna (Acridotheres tristis), originally from Asia, along with its parasites and diseases, may have accelerated the huia’s extinction. This hypothesis is based on the discovery of African and Asian ticks on preserved specimens, as noted by entomologist John G. Meyers in The Present Position of Endemic Birds in New Zealand (1923). These parasites were likely introduced via mynas, which are notorious for raiding the eggs and chicks of other bird species. The IUCN lists the myna, now also found in Australia, Africa, and North America, among the 100 of the World’s Worst Invasive Alien Species.

Like all endemic New Zealand bird species, huias faced habitat loss and competition from introduced mammals. However, they also faced intense hunting pressure. Specimens were highly sought after by wealthy European collectors and museums worldwide. The hunting of these birds was primarily driven by naturalists. Austrian taxidermist Andreas Reischek, for example, sent 212 huia pairs to the Natural History Museum in Vienna over a period of ten years, as documented by Michael Szabo in his 1993 New Zealand Geographic article, Huia, The Sacred Bird.

Additionally, Māori played a role in the species’ decline through the active trade of huia skins. In his 1888 A History of the Birds of New Zealand, Buller reported that in 1883, a group of 11 Māori received 646 huia skins in a trade. Thousands of specimens are believed to have been exported overseas as part of this trade.

Attempts to save the huia and how they failed

New Zealand’s government made a few attempts to save the huia from extinction, but these efforts were poorly organized, lacked legal enforcement, and were too few to be effective. In the 19th century, New Zealand’s conservation movement was still in its infancy.

In early 1892, the Wild Bird Protection Act was amended to prohibit the killing of huia. However, this law was widely ignored. Moreover, no huias were ever transferred to island sanctuaries set up to protect endangered native birds. A telling anecdote from Kerry-Jayne Wilson’s Flight of the Huia (2004) illustrates the issue: In 1893, a pair of huias was meant to be relocated to Kapiti Island for protection, but Walter Buller blocked the effort and instead took the birds, along with the last collected pair of living laughing owls (Ninox albifacies), as a gift for Lord Rothschild in England.

By 1901, the huia was no longer considered a protected species in New Zealand during the hunting season, sealing its fate as an extinct species.

The last sightings and the failed cloning attempts

The last confirmed huia sighting occurred in December 1907, when W. W. Smith observed three birds in the forests of the Tararua Range in the southern North Island. However, several unconfirmed but “fairly credible” sightings suggest that the bird may have survived longer. In December 1922, a man familiar with huias reported seeing three birds in Gollans Valley, near York Bay. Other sightings in the same area were documented in 1912 and 1913. The last credible, yet unconfirmed, reports came from the forests of the Te Urewera National Park: one in 1952 near Mount Urutawa, and others in 1961 and 1963 at Lake Waikareiti.

Some scientists speculate that a small, surviving population of huia might still exist in the Urewera Range, though most experts consider this unlikely. No recent expeditions have been organized with the goal of finding a living huia.

In July 1999, a group of scientists and ethicists convened to discuss the possibility of cloning the huia, a topic covered by CNN. Unfortunately, the DNA extracted from museum specimens was too degraded, making it impossible to obtain a complete huia genome for cloning. As a result, the efforts to bring the bird back through cloning were ultimately unsuccessful.

With the huia, the bird louse Rallicola extinctus also disappeared

When feather lice infestations were discovered on several preserved huia specimens in museums, scientists, upon closer inspection, identified a previously unknown but now extinct species of insect. This louse, from the family Philopteridae, which includes Ischnocera and biting lice (Mallophaga), typically lives parasitically on birds. The louse Rallicola extinctus was found on huia specimens and likely lived exclusively on this bird, making the bird its specialized host.

The extinction of many bird species is often accompanied by the loss of host-specific insect species. Numerous parasitic species have been discovered only after their host bird went extinct, identified through preserved bird specimens. A famous example is the passenger pigeon mite, whose host, the passenger pigeon, went extinct in 1914. However, it’s not always a bird that carries a specialized parasite. When the Caribbean monk seal disappeared in the mid-20th century, the nasal mite Halarachne americana also became extinct.