Laysan Rail
Encyclopedia
The Laysan Rail or Laysan Crake (Porzana palmeri) was a tiny inhabitant of the Northwest Hawaiian Island
Northwestern Hawaiian Islands
The Northwestern Hawaiian Islands or the Leeward Islands are the small islands and atolls in the Hawaiian island chain located northwest of the islands of Kauai and Niihau. They are administered by the U.S. state of Hawaii except Midway Atoll, which has temporary residential facilities and is...

 of Laysan
Laysan
Laysan , located northwest of Honolulu at N25° 42' 14" W171° 44' 04", is one of the Northwestern Hawaiian Islands. It comprises one land mass of , about 1 by 1.5 miles in size . It is an atoll of sorts, although the land completely surrounds a shallow central lake some above sea level that has...

. This small island was and still is an important seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

 colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

 loss by domestic rabbit
Domestic rabbit
A domestic rabbit, or more commonly known as simply the rabbit, is any of the several varieties of European rabbit that have been domesticated....

s, and ultimately World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Its scientific name honours Henry Palmer, who collected in the Hawaiian Islands for Walter Rothschild
Walter Rothschild, 2nd Baron Rothschild
Lionel Walter Rothschild, 2nd Baron Rothschild, Baron de Rothschild FRS , a scion of the Rothschild family, was a British banker, politician, and zoologist.-Biography:...

.

Description and distribution

It was a small bird (15 centimetres (5.9 in) from beaktip to "tail" tip, fully stretched out), a flightless
Flightless bird
Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today, the best known being the ostrich, emu, cassowary, rhea, kiwi, and penguin...

 member of the rail
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...

 family. Tail and wings had been reduced in the course of its evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 to lengths of merely 2.5 centimetre (0.984251968503937 in) and 5.4 centimetres (2.1 in), respectively, and it only had 8 primaries as opposed to 10 in volant rails. The bill, measuring 1.8 centimetre (0.708661417322835 in), was strong and straight, and the legs were also well-developed; in its overall proportions it was similar to the small rails of the genus Laterallus
Laterallus
Laterallus is a genus of birds in the rail family Rallidae. These small, relatively short-billed terrestrial rails are found among dense vegetation near water in the Neotropics, although a single species, the Black Rail, also occurs in the United States....

, such as the Black Rail
Black Rail
The Black Rail is a mouse-sized member of the Rallidae family of birds. It is found in scattered parts of North America and the Pacific region of South America, usually in coastal salt marshes but also in some freshwater marshes. It is extinct or threatened in many locations due to habitat loss...

.

Its coloration was essentially a lighter, more subdued version of that of the Baillon's Crake
Baillon's Crake
The Baillon's Crake is a very small waterbird of the family Rallidae.-Distribution:Their breeding habitat is sedge beds in Europe, mainly in the east, and across Asia. They used to breed in Great Britain up to the mid-19th century, but the western European population declined through drainage....

, a closely related species from which it possibly had evolved. The face, throat, breast and supercilium
Supercilium
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...

 were dull medium gray, and the back, wings and top of the head were pale brown with strongly contrasting feather shaft
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...

s except on the wings. Scapular (shoulder) and flank plumage were sandy brown. The characteristic black-and-white barring of the lower belly and undertail coverts often seen in the genera Porzana
Porzana
Porzana is a genus of birds in the crake or rail family, Rallidae. It has a global distribution, contains 13 living species, and 4-5 recently extinct ones...

and Rallus
Rallus
Rallus is a genus of wetland birds of the rail family. Sometimes, the genera Lewinia and Gallirallus are included in it. Six of the species are found in the Americas, and the three species found in Eurasia, Africa and Madagascar are very closely related to each other, suggesting they are descended...

was much reduced. Feet and bill were a yellowish-olive green, and the iris was ruby red. The sexes were alike; downy
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...

 young were black all over, with conspicuously long dark legs and a yellow bill, and immature birds had the entire underside colored pale brown.

It was endemic to Laysan (although an introduced population was present on Midway Atoll
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

 for some decades early in the 20th century); some authors have noted that there were tales of flightless rails on other Hawaiian islands, but they refer to local forms extinct before Western contact. A supposed early record from Lisianski Island
Lisianski Island
Lisianski Island is one of the Northwestern Hawaiian Islands, with a land area of and a maximum elevation of above sea level. Honolulu is away, to the southeast. Linked to Lisianski are the extensive Neva Shoals...

 might more likely refer to migrant rails, or alternatively to a distinct species that evolved in parallel
Parallel evolution
Parallel evolution is the development of a similar trait in related, but distinct, species descending from the same ancestor, but from different clades.-Parallel vs...

 to the Laysan Rail; however, given the barrenness of Lisianski and the lack of material evidence (Olson & Ziegler, 1995), this is quite unlikely.

Ecology and habits

The Laysan Rail was an opportunist that fed mainly on invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s such as moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

s, Neoscatella sexnotata (brine flies
Ephydridae
Ephydridae is a family of insects in the order Diptera.Shore flies are tiny flies that can be found near seashores or at smaller inland waters, such as ponds...

), blowflies
Blow-fly
Calliphoridae are insects in the Order Diptera, family Calliphoridae...

, and their larvae
Maggot
In everyday speech the word maggot means the larva of a fly ; it is applied in particular to the larvae of Brachyceran flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and Crane flies...

; plant leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

, seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s, and eggs and carcasses of seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

s were eaten when they were available. It was an aggressive bird that would fight off other species, particularly the Laysan Finch
Laysan Finch
The Laysan Finch is a species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae, that is endemic to the Northwestern Hawaiian Islands. It is one of four remaining finch-billed Hawaiian honeycreepers, and is closely related to the smaller Nihoa Finch. The Laysan Finch is named for...

: the latter is very adept at breaking open seabird's eggs to consume the contents, while the rail was much less so. Consequently, rails would linger around in the seabird colony, be on the lookout for finches which had just cracked open an egg, chase these away, and consume the egg's contents. On Midway
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

, the rails were seen to steal food from domestic chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

 (Olson, 1996). There exists no permanent source of freshwater on Laysan, and while the rails must have been able to cover their needs from the body fluids of prey and the content of eggs, they would eagerly drink from and bathe in pools of water remaining after heavy rain, or a pan of water provided by an observer.
Although it was flightless, it would use its wings to assist in keeping balance when running quickly and jumping; this way, they were able to make jumps of somewhat less than 1 metres (3.3 ft). They were nimble and restless, retreating to the tussocks to avoid predators, but chiefly to escape the mid-day heat; if they felt threatened, they often hid in the burrows of petrel
Petrel
Petrels are tube-nosed seabirds in the bird order Procellariiformes. The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group...

s. The birds were most active in the open in the morning and afternoon hours, but it could regularly be seen all day and heard calling at night. Laysan Rails had no natural enemies apart from occasional predation by frigatebird
Frigatebird
The frigatebirds are a family, Fregatidae, of seabirds. There are five species in the single genus Fregata. They are also sometimes called Man of War birds or Pirate birds. Since they are related to the pelicans, the term "frigate pelican" is also a name applied to them...

s; all reports remarked upon its fearlessness, and if an observer stood still, rails would approach and even climb over him to search for scraps of food. One bird, removed from its nest in an attempt to photograph the eggs, would immediately return to protect her clutch. The species was somewhat territorial, more so during the breeding season. On Laysan, carrying capacity
Carrying capacity
The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment...

 was reached at 10–13 m² (107.6–139.9 sqft) of habitat per bird, while on Midway, population density was one-fourth of this figure; in captivity, an enclosure of roughly 8 square metres (86.1 sq ft) was sufficient for two pairs, but introducing more birds into this space would lead to fights.

Vocalizations

When active, Laysan Rails would ever so often stand still and utter one to three soft warbling chirps. In courtship or territorial defense (reports are not clear, but probably the latter) two birds would stand opposing each other, fluffing up their plumage, and give rattling, scolding calls not unlike a mechanical alarm clock
Alarm clock
An alarm clock is a clock that is designed to make a loud sound at a specific time. The primary use of these clocks is to awaken people from their night's sleep or short naps; they are sometimes used for other reminders as well. To stop the sound, a button or handle on the clock is pressed; but...

 (Udvardy, 1996). Soon after dusk, the entire population could be heard to engage in a brief bout of vocalization, which Frohawk (1892) described as sounding like
"[...]a handful or two of marbles being thrown on a glass roof and then descending in a succession of bounds."

Downy
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...

 young would vocalize a lot, and their calls were rather loud in proportion to their tiny size.

Reproduction

On Laysan, courtship and the start of nest-building was in April, with eggs being laid from May to June and the height of the nesting season taking place in June and July; there is a report of recently-hatched young birds from Midway in March, but this seems to be unusually early. On Laysan, nests were built in tussocks of endemic Cyperus pennatiformis
Cyperus pennatiformis
Cyperus pennatiformis is a rare species of sedge known by the common name coastal flatsedge. It is endemic to Hawaii, where it grows on the islands of Maui, Kauai, and Laysan...

subsp. bryanii, kāwelu (Eragrostis variabilis) and introduced Bermuda Grass (Cynodon dactylon
Cynodon dactylon
Cynodon dactylon , also known as Dūrvā Grass, Bermuda Grass, Dubo, Dog's Tooth Grass, Bahama Grass, Devil's Grass, Couch Grass, Indian Doab, Arugampul, Grama, and Scutch Grass, is a grass native to north and east Africa, Asia and Australia and southern Europe...

) around the lagoon, while on Midway, it nested in any shelter that seemed convenient, such as naupaka kahakai (Scaevola
Scaevola
Scaevola is a genus of flowering plants in the Goodenia family, Goodeniaceae. It consists of more than 130 tropical species, with the center of diversity being Australia and Polynesia, including Hawaii....

 taccada
) thickets and pōhuehue (Ipomoea pes-caprae
Ipomoea pes-caprae
Ipomoea pes-caprae, also known as Beach Morning Glory or Goat's Foot, is a common pantropical creeping vine belonging to the family Convolvulaceae. It grows on the upper parts of beaches and endures salted air. It is one of the most common and most widely distributed salt tolerant plants and...

subsp. brasiliensis) stands. The nests were placed on the ground or inside the base of a tussock; in the latter case the birds would rearrange the dried dead leaves to form a roofed cavity reached through a small tunnel some 15 centimetres (5.9 in) long. Nests were lined with soft dried plant material and down
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...

 of seabirds.

The clutch
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...

 consisted of 3 or less frequently two eggs (as opposed to some 5-10 for related continental rails). These were oval without being conspicuously more rounded on one end, measuring 31 x 21 mm and being pale olive buff in base color, irregularly marked all over in pale raw sienna or purplish grey. The sexes mated either for life or for an entire breeding season and shared incubation duties, although females seem to have spent more time incubating than males.
The young hatched after approximately 20 days of incubation (perhaps somewhat less; in related species it is usually 16–20 days) and were tended for by both parents for about one month. Five days after hatching, the young were able to run as quickly as adults. Hadden (1941) described a three-day-old chick as follows:
"A black velvet marble rolling along the ground. Its little feet and legs are so small and move so fast that they can hardly be seen."

Extinction

Laysan is considered one of the most important seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

 colonies in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It has thousands of Black-footed Albatross
Black-footed Albatross
The Black-footed Albatross, Phoebastria nigripes, is a large seabird from the North Pacific of the albatross family Diomedeidae. It is one of three species of albatross that range in the northern hemisphere, nesting on isolated tropical islands...

, Laysan Albatross
Laysan Albatross
The Laysan Albatross, Phoebastria immutabilis, is a large seabird that ranges across the North Pacific. This small two-tone gull-like albatross is the second most common seabird in the Hawaiian Islands, with an estimated population of 2.5 million birds, and is currently expanding its range to new...

 as well as shearwater
Shearwater
Shearwaters are medium-sized long-winged seabirds. There are more than 30 species of shearwaters, a few larger ones in the genus Calonectris and many smaller species in the genus Puffinus...

s and tern
Tern
Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...

s. The island also held 5 unique (sub)species of land- and waterbirds, including the Laysan Rail. The extinction of this species is particularly unfortunate as it could have easily been avoided.

The rail was initially threatened when domestic rabbit
Domestic rabbit
A domestic rabbit, or more commonly known as simply the rabbit, is any of the several varieties of European rabbit that have been domesticated....

s were introduced to Laysan. With no predators to control their numbers the rabbits soon ate the entire vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...

 cover on the island. This turned the island into a barren dust bowl, sending the Laysan Millerbird
Laysan Millerbird
The Laysan Millerbird was a subspecies of the Millerbird, similar in appearance to the remaining subspecies, the Nihoa Millerbird. Its dorsal side was brown, and its belly was grayish...

 and the Laysan Apapane (both subspecies endemic to the island) to extinction; the Laysan Finch
Laysan Finch
The Laysan Finch is a species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae, that is endemic to the Northwestern Hawaiian Islands. It is one of four remaining finch-billed Hawaiian honeycreepers, and is closely related to the smaller Nihoa Finch. The Laysan Finch is named for...

 and Laysan Duck
Laysan Duck
The Laysan Duck , also known as the Laysan Teal because of its small size, is an endangered dabbling duck endemic to the Hawaiian Islands...

 both managed to survive. In the 1900s, when destruction of the vegetation by the rabbits had only just started, the rail's population was around 2000 mature birds and at carrying capacity; it remained so until at least the early 1910s, but declined thereafter. In 1923, only two birds could be found on Laysan, and of eight that were on that occasion brought from Midway, at least two died almost immediately from lack of food and shelter (Olson, 1996). The species is believed to have become extinct on Laysan during 1923, probably mainly because no habitat for nesting was left in sufficient quantity to maintain the population.
The last rail was seen on Eastern Island in Midway in June 1944. (Raozon, 2001).

External links

  • UVA.nl, 3D view of specimen RMNH 110.009 at Naturalis
    Naturalis
    Naturalis is the national natural history museum of the Netherlands, based in Leiden. It originated from the merger of the Rijksmuseum van Natuurlijke Historie and the Rijksmuseum van Geologie en Mineralogie in 1984. In 1986 it was decided that the museum had to become a public museum and a new...

    , Leiden (requires QuickTime
    QuickTime
    QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...

    browser plugin).
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