What makes a bird a bird?
When you think of a bird, the first thing that likely comes to mind is its ability to fly. Wings and flight are often considered defining characteristics of birds. However, not all birds can fly. Penguins, rheas, ostriches, and emus are well-known examples of flightless birds, but there are many others that are less familiar.
Over the years, many flightless bird species have become extinct, often because they couldn’t escape introduced land predators. Despite this, some fascinating flightless birds still exist today, firmly grounded but no less remarkable. Here are 10 of the more unusual examples.
The Inaccessible Island rail is the smallest flightless bird that is still in existence. It solely inhabits Inaccessible Island, part of the archipelago of Tristan da Cunha.
Henry Martyn Rogers, after whom the species is named, observed the Inaccessible Island rail while he was a missionary priest at Tristan Da Cunha. In a book published by his wife after his death is to be found the following notes:
“… the most interesting bird of all is the island cock, of which I was fortunate in procuring the first specimen known to science … It is a small bird of the rail species, I think, wingless, unable to fly, but can run with great speed, shelters in the tussock, and lives in a burrow. Its eggs are not known, it does not migrate, and it feeds, I understand, on insects and worms. Its radius once extended to Tristan, but it is now solely found on Inaccessible. … There are no rats at Inaccessible, and in this it has an advantage over Tristan.”
Estimates put the current population of the Inaccessible Island rail at about 8,400 individuals, which is probably the maximum the island can support. It is generally safe from predators on the island except for the Tristan thrush, which will occasionally prey upon its chicks.
However, although the Inaccessible Island rail is abundant across the island it is the fact that it inhabitants just one isolated location that puts the species most at risk, for example, from an introduced predator such as rats.
Also known as the Galapagos cormorant, the flightless cormorant is just one of the highly unusual animals that inhabits the islands. It is the only cormorant to live on the Galapagos and is found on two islands, Fernandina and Isabela, breeding near the coldest waters and nesting on shingle or lava outcrops.
The flightless cormorant is the largest member of the cormorant family and the only one unable to fly. It looks similar to its cousins except that its wings are about a third of the size required for flight in proportion to its body. The keel on the breastbone where the large muscles needed for flight are attached is also greatly reduced.
With an estimated population of just 1,500 individuals the flightless cormorant is one of the world’s rarest birds and its population fluctuates dramatically in response to environmental changes such as El Niño or volcanic eruptions. Females can breed up to 3 times a year so recovery from environmental disasters can be fairly quick.
They have few predators; at sea there is a risk from sharks while on land they are at risk from owls and hawks and introduced predators such as cats and dogs. Fishing with nets is also a threat to these birds and conservation efforts recommend the prevention of fishing with nets around the bird’s foraging range.
The weka is a large, brown flightless bird that is endemic to New Zealand. Currently four subspecies of weka are recognized; the North Island weka, the Western weka, the buff weka and the Stewart Island weka.
In 1835, William Yate, one of the earliest New Zealand missionaries described the North Island weka as;
“A bird so called from the largeness and rotundity of its breast, about the size of the crow, and remarkable for the deep red with which the feathers are tinged upon the back and under the wings. Its legs are about five inches long, and rather slender for the size of the body. Its beak is like that of the fieldfare; and the eye of a light-brown colour, with a ring of white round it.
“These birds are never found in the woods; but on the sides of brooks, and in barren land, amongst the stunted fern.”
Because of their feisty and curious personalities, weka are important to some Māori iwi, and they have been used as a source of food, perfume, feathers for clothing and oil to treat inflammations.They also have a reputation for pilfering crops, food, small shiny items and even bags of sugar.
Another bird endemic to New Zealand, the kakapo, also known as the owl parrot, is a large, flightless, lek-breeding, nocturnal, ground dwelling parrot – so more than a bit unusual.
It was originally thought that the kakapo was related to the ground parrots and night parrot of Australia but recent studies have refuted this theory. It appears to have evolved to occupy an ecological niche normally filled by mammals – the only land mammals native to New Zealand are 3 species of bat.
Although, the kakapo cannot fly it has very strong legs and is an excellent climber, able to ascend to the top of the tallest trees. From there it can ‘parachute’ for a few metres, by leaping and spreading its wings.
The kakapo is critically endangered and in the 1970s was thought to be extinct. Before humans arrived they were common throughout New Zealand’s forests but due to predation from, for example, cats, rats and stoats, numbers are thought to be down to just over 100 individual birds.
A conservation programme has been implemented to move the remaining birds to predator-free islands, although attempts have not always been successful. Kakapo have very low genetic diversity and, as a consequence, low fertility, so conservation efforts have recently focused on managing matings using artificial insemination.
The Falkland steamer duck is one of only two birds endemic to the Falkland Islands and one of the three out of four steamer ducks that is flightless.
It derived its scientific name from its short wings (“brachy” meaning short and “pteron” meaning wing), and its behaviour that gave it the name “steamer duck” was observed by Charles Darwin in 1833 when he visited the Falklands on The Beagle:
“In these islands a great loggerheaded duck or goose (anas brachyptera), which sometimes weighs twenty-two pounds, is very abundant. These birds were in former days called, from their extraordinary manner of paddling and splashing upon the water, race-horses; but now they are named, much more appropriately, steamers.
“Their wings are too small and weak to allow of flight, but by their aid, partly swimming and partly flapping the surface of the water, they move very quickly. The manner is something like that by which the common house-duck escapes when pursued by a dog; but I am nearly sure that the steamer moves its wings alternately, instead of both together, as in other birds. These clumsy, loggerheaded ducks make such a noise and splashing, that the effect is exceedingly curious.”
Steamer ducks are notorious for their brutality and when a neighbouring bird encroaches on a male bird’s territory a vicious and bloody battle will take place in which the female of the pair will also take part. Fights can last up to 20 minutes and they will even kill other species of waterfowl, which is quite unusual in the bird world. With other territorial species arguments usually consist of a lot of puffing and posturing but actual combat rarely takes place.
Falkland steamer ducks are quite difficult to distinguish from flying steamer ducks as they occupy the same habitat and although flying steamer ducks are able to fly they rarely do.
The Titicaca grebe is found exclusively on Lake Titicaca, a large, deep lake in the Andes on the border of Peru and Bolivia, Lake Uru Uru in Bolivia and several small lakes that connect to Lake Titicaca in wet years.
It is alternatively known as the short-winged grebe and, although it is flightless, it will use its wings to help it run over considerable distances. It is an excellent diver reaching speeds of up to 3.5 km per hour. Like all grebes it feeds mainly on fish with about 95% of its diet made up of Orestias pupfish.
The Titicaca grebe is listed as endangered as it has recently suffered very rapid declines in its populations. Unlike many flightless birds that are threatened due to introduced predator species, Titicaca grebes are mostly at risk from the use of monofilament line gill nets, which started to be used by fishermen in the 1990s and which drown thousands of the birds.
Other threats include the collection of the grebe’s eggs, pollution from boat traffic and overharvesting of the reeds that make up its prime habitat but these are deemed to be irrelevant and the Titicaca grebe is able to recover quite quickly from small population losses. Titicaca grebes are not generally hunted, as adult birds, like all grebes, taste of rancid fish.
The Campbell teal is a nocturnal, flightless, dabbling duck which, as the name suggests, is endemic to the Campbell Islands in New Zealand.
The Campbell teal was driven to extinction on Campbell Island, the largest island in the group, by introduced rats that ran aground from the Norwegian sealing and whaling ships that visited Campbell Island in the 1800s. The flightless birds were unable to escape the invasive predators, which ate their chicks and eggs. It was thought that Campbell duck had disappeared entirely until in 1975 a small population was discovered on nearby Dent Island that had remained free of rats. To prevent total extinction 11 ducks were taken into captivity for breeding purposes.
As the wild behaviour of the ducks had not been previously observed, captive breeding was initially difficult to achieve with a range of techniques developed using trial and error. Finally, in 1994 a Campbell teal named Daisy accepted a mate and laid eggs which hatched ducklings.
Since then captive breeding has occurred ever year with males that originated from the wild paired with captive females.
To restore the ecological balance in the 1990s, cattle, sheep and cats were removed from Campbell Island and in 2001 in the world’s largest rat eradication campaign, more than 120 tonnes of poisoned bait were dropped by helicopter over the island with the island being officially declared rat free in 2003.
In 2004, 50 Campbell teal were re-introduced to Campbell Island after an absence of more than a century. The ducks have thrived in their ancestral home and the species has had its threat status reclassified to endangered.
Guam is a territory of the United States, situated in the northwestern Pacific Ocean and home to the Guam rail, a species of flightless bird, which was nearly driven to extinction in the 1970s.
The Guam rail, known locally as ko’ko’, is a secretive and territorial bird but can be observed bathing or feeding along the edges of roads or fields. It nests all year round on the ground, and evolved in the absence of natural predators such as snakes or rats. The population was estimated to be around 70,000 in the 1960s and was so abundant it was hunted for food.
However, after the end of World War II, the nocturnal brown tree snake was accidentally introduced to Guam, probably as a stowaway in a military ship travelling from Papua New Guinea, its native habitat.
The snakes quickly colonized the island and the population of the Guam rail began to decrease rapidly along with the rest of Guam’s native birds, such as the Guam kingfisher and the cardinal honeyeater, which had no defences against the snakes.
In 1982, zoologist Bob Beck, began a campaign to capture the Guam rail and other remaining wild birds to save them from extinction. There are now over 100 birds in captivity on Guam with a further 35 on mainland U.S. And in recent years efforts have been made to reintroduce the Guam rail back into the wild on Guam with some moderate success.
The Takahē is a so-called ‘Lazarus species” in that it was thought to be extinct but was in fact rediscovered some time later.
Also known as the South Island takahē, it was considered to be extinct after the last four known specimens were collected from Fiordland, a geographic region in the southwest of New Zealand, in the late 1800s. It was famously rediscovered by Geoffrey Orbell, a New Zealand doctor and keen bush walker,
Dr. Orbell had been fascinated by the takahē since childhood and circumstantial evidence and possible sightings convinced him it was still alive.
In 1948 he persuaded a group of friends to join him on a trek into the Murchison Mountains to search for the large, flightless bird. In November they successfully tracked and photographed three birds with the news of the discovery stunning the world of ornithology and making headline news around the globe.
Dr. Orbell described the moment he spotted the takahē:
“Suddenly I saw in a clearing in the snow grass a bird with a bright red beak and a blue and green colouring. And there, no more than twenty metres away from us stood a living Notornis, the bird that was supposed to be extinct.”Takahē are now protected in the Fiordland National park, although the populations has not recovered to the levels hoped for. Domestic deer pose a threat and the park has introduced controlled deer hunting. Future plans including moving the takahē to islands free from predators.
Endemic to Lord Howe Island off the Australian coast, the Lord Howe woodhen is a small, olive brown bird that lives in sub-tropical forests, feeding on worms, crustaceans, fruit and occasionally taking eggs from shearwaters and petrels.
When explorers first discovered Lord Howe Island in 1788, they identified 15 species of birds including the then common woodhen. As they had never been hunted they were not afraid of humans and became an easy food source for the sailors that subsequently visited.
Arthur Bowes Smyth, a surgeon who looked after the crew on the slave ship the Lady Penrhyn kept a diary documenting the natural history he observed in Australia describing the woodhen as:
“… a curious brown bird abl. the size of the Land Reel in England walking totally fearless and unconcern’d in all part around us, so that we had nothing more to do than to standstill a minute or two and knock down as many as we pleas’d wt. a short stick if you throw`d at them and miss’d them or even hit them without killing them, they never make the least attempt to fly away and indeed wd. only run a few yards from you and be as quiet and unconcern’d as if nothing had happen’d.”
Since then 9 of the 15 species have become extinct and by the 1980s the Lord Howe woodhen was on the very brink of extinction with just 15 individual birds remaining. A study was undertaken to determine the cause of this catastrophic decrease in population and although a number of possibilities were put forward, such as introduced rats and the Tasmanian masked owl, the decline was correctly attributed to feral pigs and cats.
A conservation programme eliminated the pigs and cats, as well as some other animals such as goats, which led to a recovery in the numbers of Lord Howe woodhen and today there are about 250 birds on the island, which is probably the optimal population size for the area.
One Response
Is there a sea bird that becomes flightless after breeding?
Saw one yesterday at Saltburn
Interesting
Janet Shaw