The Hawaiian Rail (Porzana sandwichensis), Hawaiian Spotted Rail, or Hawaiian Crake was a somewhat enigmatic species of diminutive rail that lived on the Big Island of Hawai’i, but is now extinct.
It was a flightless bird that was apparently found in shrubland and secondary growth on abandoned fields, and in times of danger had the habit of hiding in Polynesian Rat burrows.
Specimens are known or assumed to be from an area which roughly corresponds to the middle elevations of today’s Puna district around the present settlement of Mountain View, below the primary rainforest. A dark form and a lighter, spotted one are known (see below).
The first collections were of individuals of the lighter form, of which today 5 specimens seem to exist: in the Naturalis in Leiden (one: RMNH 87450), in the American Museum of Natural History and New York City (1). Of the dark form, several additional individuals are present in collections in Cambridge (Museum of Natural History, 1), London (Natural History Museum, 1), Vienna, New York City (1), and Honolulu (Bishop Museum, 2). One 1778 painting by William Ellis (plate 70) depicts a light bird, possibly the Leiden specimen (which was apparently collected in late January/early February, 1779), and in more recent times, subfossil bones have also been recovered.
The native name for the bird was apparently moho, said to refer to a small “bird that crows in the grass”. The name iao or ? iao was claimed to refer to a moho-like but smaller bird; it is not clear whether this bird was the distinctive lighter form or the extinct, unnamed small rail (see below).
The bird is referenced in the old Hawaiian proverb ?A?ohe mea n? Na e ho? opuhili, he moho no kMakaniakani, which means roughly “nothing can blow him off course, he is like a moho in the wind”; it was used to indicate admiration for an undaunted or determined person (as the bird was unable to fly, it was not affected by the wind).
This is not to be confused with the taxonomical name Moho, which are the ????; also from Hawaii, also extinct, but completely unrelated birds.
Systematics
Considerable confusion has been created by the existence of two distinct forms. While it cannot be completely excluded that early specimens were collected on another island, only O’ahu and Kaua’i? It seems possible given the history of the specimens’ collection, and only on the latter island is a similar-sized species now known to have once existed. However, the bones from KauaI?I am in the upper size range of those found of sandwichensis, while the specimens of the lighter form are all of smaller birds.
On the Big Island, a smaller species of Porzana is now known from subfossil bones found on the southwestern slope of Mauna Kea, but this bird was only the size of a Laysan Crake; it may have been the bird named iao or iao, which would place its extinction at a relatively recent date. In addition, there are some bones of a third species, approximately 15% larger than P. sandwichensis, found near Kailua-Kona.
The generally accepted theory is that the lighter birds represent immatures, and certainly only such specimens have been described as young birds (the Hanover specimen is labeled as “juvenile”), but since the exact collection localities are not known with sufficient detail, only DNA analysis could resolve this question, particularly since the recovered bone material can also be expected to yield analyzable DNA fragments.
At any rate, both light and dark birds are today treated as a single species, the junior synonyms of which are as follows:
- Rallus sandwichensis Gmelin, 1789
- Rallus obscurus Gmelin, 1789
- Pennula millei (lapsus) Dole, 1878
- Pennula millsi
- Pennula wilsoni Finsch, 1898
- Pennula ecaudata King
The last 5 names refer to the dark form. However, Rallus obscurus is something of a mystery, as it is generally assumed that at the time of Gmelin’s writing, the species was only known from light birds (which were described as sandwichensis on the preceding page of Gmelin’s work), but he seems to have seen a specimen of his obscurus at the Leverian Museum (Stresemann, 1950).
Extinction
Specimens of the light form were collected in 1778 on the third Cook expedition; the dark form was supposedly not found at that time (but see above).
Apparently, all or at least most specimens of the latter were procured over a short period around 1860 by James D. Mills, the last one in 1864. The last reliable sight record was in 1884, with a doubtful one in 1893; a dedicated search in 1887 failed to find the bird, but as it was rather cryptic, this cannot be taken as unequivocal proof that it was completely extinct by then.
As neither the Small Asian Mongoose nor mosquitoes (which transmit fowlpox and avian malaria, both exceptionally lethal to Hawaiian endemic birds) were present on the Big Island until 1883 and the 1890s, respectively, this species’ extinction was probably caused by introduced European rats, cats, and possibly dogs.
Hunting, sometimes assumed to have played a major part, probably was not significant as the bird was protected by a kap, which prohibited hunting except by all. I until 1819. After that, the few specimens that were collected suggest it was not extensively hunted even after the kapu was abolished.
References
- Gmelin, Johann Friedrich (1789): [Description of Porzana sandwichensis]. In: Systema Naturae per regna tria naturae secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (13th ed.) 1, part II: 717. Georg Emanuel Beer, Lipsiae [Leipzig]
Distribution and Habitat
It was unique to the Big Island of Hawaii. It was found in the lower altitude regions on the island.
Its preferred habitats were open countryside such as old fields, lowland scrublands, lightly wooded areas, and perhaps the edges of wetlands. Unlike many modern birds that inhabit deep forests or high mountain ranges, the Hawaiian Rail was a bird of transitional and open landscapes–environments that combined patches of cover with open ground for foraging. The bird likely avoided high-altitude and dense rainforest regions. It thrived instead in semi-natural habitats, created by abandoned clearings or native grasslands. These habitats provided a perfect blend of shelter, foraging, and reduced competition.
The Hawaiian Rail is vulnerable to environmental changes because of its restricted range and habitat. Even minor changes in the vegetation or ground structure can affect its ability to survive. This is especially true given its low flight abilities and dependence on ground cover for protection.
Feeding Behavior and Diet
Like many extinct island species, the Hawaiian Rail’s diet is based on a combination of physical evidence, observations, and ecological inference. It was an omnivorous animal that fed on insects as well as small invertebrates.
The bill shape and its foraging behaviour suggest that the shrew ate by probing into leaf litter and moist soil. Its animal diet would have been dominated by beetles, spiders, and ants. Small snails or worms may also have played a role. The bird would have preferred moist, shady habitats where these prey items were abundant.
The Hawaiian Rail also consumed seeds and berries, as well as tender shoots. This was especially true during periods of the year when insects were in short supply. It could have eaten soft parts of native plants using its thin bill to pick up and probe.
All of its hunting took place on the floor because it was unable to fly or nearly unable to fly. To hide from predators, it would have required dense ground cover. Its foraging style and secretive nature made it difficult to observe even when it was present in the wild.
Vocalizations
The Hawaiian Rail’s vocal behaviour is not well understood. There are no recordings and few firsthand accounts. We can, however, infer some things based on what we know about other species of the rail family.
Rails are usually a vocal bird. They use a variety of calls to communicate with each other in dense vegetation. The sounds used include grunts and chirps as well as low-pitched whistling. These are used to attract mates, defend territories, and communicate between individuals.
The Hawaiian Rail, being a ground-dwelling and solitary species, probably produced soft, discreet vocalizations–sounds designed to carry through vegetation without attracting predators. Like many rails, it may have been vocal at dawn and dusk. This is especially true during breeding season, when territorial boundaries must be established and maintained.
We will never be able to hear its exact call because it disappeared before audio recording was widespread. The bird’s voice is silent, as well. This is a cultural and ecological loss.
Conservation Status and Extinction
Hawaiian Rails are currently classified as extinct. The last specimens confirmed were collected in the mid-1800s, and the last credible sightings occurred by the 1880s. Despite occasional rumors and unconfirmed accounts, no more living individuals were documented after that.
The pattern of its extinction is all too common in island ecosystems. The arrival of Polynesian colonists brought new predators. These included rats that preyed upon eggs, chicks, nd possibly even adults. Later, European settlers introduced cats, dogs, and other mammals, which increased the predation pressure.
Conclusion
The story of Hawaiian Rail serves as a reminder of the fragile island ecosystems and the sometimes overlooked consequences of environmental disruption. The Hawaiian Rail was not a bird that inspired myths or captured birdwatchers’ attention with its bright plumage and dramatic song. It was small, quiet, and secretive. A major blow to Hawaii’s rich natural history, not just for its biodiversity.
The rail developed in isolation and is perfectly adapted to the open lowland habitats of the Big Island. It filled a niche that was unique for thousands of years. It helped control insect populations, spread seeds, and contributed to the ecological equilibrium. It had little chance against introduced predators and habitat destruction, as well as environmental changes.
As we reflect on the past, we have an opportunity to look ahead. We should not only mourn the loss of Hawaiian Rails, but also take action. The ongoing conservation efforts of native species that are still alive must be strengthened. Invasive species must also be controlled and habitats restored.
It may be that the Hawaiian Rail is no more, but we can still learn from its legacy. Let it be a sign–not that we have failed, but rather of the need to value all species, regardless of how small, timid, or quiet they are.
