Ula-ai-hawane

The Hawaiian Islands once hosted 57 species of honeycreepers

Honeycreepers (Drepanidini), a tribe within the finch family (Fringillidae), are found only on the Hawaiian Island chain. Honeycreepers are closely related as sister species to the rosefinches (Carpodacus), yet many species have developed characteristics that differ from those of finches. Honeycreepers exhibit a great deal of morphological diversity – the result of adaptive radiation in an island environment.

A report on the speciation of Hawaiian honeycreepers (2011) indicates that their ancestors originated from Asia and diverged from the rosefinches about 7.2 million years ago. Biologist Heather R. L. Lerner and other scientists believe that the ancestors of the honeycreepers arrived on the Hawaiian Islands approximately 5.2 to 7.2 million years ago. From the rosefinches, various descendant lineages and genera of honeycreepers developed on the individual islands at different times.

As is often the case with island birds, the specialization that enables them to survive in large numbers and in various forms within a confined space becomes a vulnerability when threats or competitors emerge. David Day notes in The Doomsday Book of Animals (1981) that honeycreepers with the largest distribution area and no significant regional variations were best able to survive.

Today, there are 24 genera of honeycreepers with about 57 species and several subspecies. Approximately 18 species went extinct in prehistoric times, and 21 species probably disappeared more recently. All other species are critically endangered or threatened with extinction. The Ula-ai-hawane, a monotypic species, is among the extinct honeycreepers.

In Hawaii, not only a large number of bird species have gone extinct but also many insects and snails. For example, the second-largest endemic moth species, the Kona giant looper, the Koolau spur-winged long-legged fly, and the tree snails Achatinella buddii and the yellow-tipped Oahu tree snail disappeared in the early 20th century.

Ula-ai-hawane – Fact sheet

Alternative name	ʻUla-ʻai-hāwane
Scientific name	Ciridops anna, Fringilla anna
Original range	Big Island (Hawaii)
Date of extinction	1892
Causes of extinction	habitat loss, animals introduced to islands, loss of forage plants, introduced diseases

Different beak shapes: Nectar feeders and seed eaters

Through adaptive radiation, Hawaiian honeycreeper species have evolved to have different beak shapes. With variously shaped beaks and tongues, these birds have specialized on different plants or food sources, allowing them to fill a wide array of ecological niches. Pointed beaks typically indicate that the birds feed on insects and/or nectar, long downward-curved beaks are usually adapted for extracting nectar from flowers, and pincer-like beaks may suggest specialization on snails as a food source.

The Ula-ai-hawane had a thick and short beak. It fed on the seeds and the flower nectar of the Hawane tree (Pritchardia). This is also reflected in its name, as the bird species is referred to by Hawaiians as Ula-Ai-Hawane, which means “the red bird that feeds on the Hawane berry.” With its tubular tongue, it could suck nectar from the tree’s flowers.

The German common name Annakleidervogel and the species epithet anna are derived from Anna Cate Dole. She was the wife of lawyer and later Hawaiian governor Sanford Dole, who discovered the Ula-ai-hawane in 1859 and described it in 1879.

A bird of “impetuous nature”

The Ula-ai-hawane inhabited forests in the hill and mountain regions on Big Island, the main island of Hawaii. It was known from the districts of Kona and Hilo and frequented the area around the extinct Kohala volcano. At the time of its discovery, the Ula-ai-hawane was already considered rare.

Honeycreepers are generally categorized into nectar feeders and seed eaters. The Ula-ai-hawane belonged to the nectar feeders, which are mostly black and red in color. There are no detailed accounts of the life and behavior of the Ula-ai-hawane. Only British ornithologist Robert Cyril Layton Perkins, who extensively studied Hawaii’s fauna, noted in 1903 in Fauna Hawaiiensis that the Ula-ai-hawane was a shy and elusive bird of “impetuous nature.”

Since the arrival of the first humans on the Hawaiian Islands in the late 1st millennium AD, the number of honeycreepers steadily declined. In the two centuries following the discovery of the archipelago by Europeans in 1778, even more honeycreeper species disappeared.

The last recorded sighting of the Ula-ai-hawane was on February 20, 1892. Bird collector Henry C. Palmer, working on behalf of British banker and zoologist Walter Rothschild, shot the bird in the swampy mountain forests on Mount Kohala on Big Island.

Ornithologist George Campbell Munro claimed to have seen a bird in the same area in 1937 that exhibited the characteristic coloring of the Ula-ai-hawane. However, he later doubted whether it was indeed this species. Munro wrote in Birds of Hawaii in 1960 about the encounter:

“The black head and gray neck are striking features (…) the fleeting observation of a bird’s head and neck showing this characteristic coloring makes me almost certain that I saw one in 1937 (…). It is unlikely that I saw this bird, yet it is possible.”

Causes of extinction: Deforestation, invasive species, diseases, plant decline

The IUCN suspects that the primary cause for the disappearance of the Ula-ai-hawane was the deforestation of Big Island for the conversion of natural landscapes into agricultural lands. This may have also led to a particularly high number of rats, which preyed on the Ula-ai-hawane population. Tree rats are also known for stealing bird eggs. Additionally, other animals kept on Big Island destroyed the habitat of the endemic wildlife, especially in the mountains where introduced livestock grazed (such as cows, pigs, goats, or deer).

Furthermore, the World Conservation Union attributes the occurrence of avian malaria as a cause of extinction, a parasitic bird disease caused by single-celled blood parasites (Plasmodium). Mosquitoes typically transmit the parasites to birds. The study Avian Malaria in Hawaiian Forest Birds (2015) investigates the impact of avian malaria on the birds of Hawaii and finds evidence that the introduced avian malaria contributed to the decline and extinction of many endemic forest birds. In addition to avian malaria, avipoxvirus, a highly contagious and often fatal viral disease, is considered one of the diseases brought to the Hawaiian Islands by non-endemic birds.

Some scientists believe that the Ula-ai-hawane primarily fed on the immature fruits of the Pritchardia species endemic to Big Island. The birds were often observed near these fan palms, suggesting they might have been dependent on them. Several fan palms of the genus Pritchardia, which are found almost exclusively on the Hawaiian Islands, are now very rare, endangered, or have been missing for years. Researchers therefore suspect that the gradual disappearance of these palms may have contributed to the extinction of the Ula-ai-hawane.

David Day also considers direct persecution by humans as a cause for the disappearance of the honeycreepers. Some birds of this tribe were hunted for their beautiful feathers – and the rarer the birds became, the more coveted their feathers were for bird collectors. This was also the fate of the Hawaii mamo (Drepanis pacifica), whose yellow feathers were used to make royal hats and cloaks.