Tag Archives: extinct animals

Lesser bilby – the yallara

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Lesser bilby – the extinct rabbit-eared bandicoot

On a personal note…I clearly remember the first time I saw a picture of a bilby. I was just staring at the photo thinking there’s no way this creature is legit: this must be a hoax, a digitally manipulated image of a rabbit and some kind of other rodent…
In fact, this is a recurring impression for me – certain animals simply look so beautifully unreal like they were fictional characters from a weird dream or an animated movie. Of course, it’s just a feeling evoked by the amazing diversity and whimsiness of our planet’s wildlife, but in some cases this impression proves to be right with time :) : in 2018 Dreamworks released an animation short about a bilby meeting a chick in the dangerous outback of Australia.

Bilby – short animation
©Copyright Dreamworks via CartonBrew.com

I really hope Dreamwork’s short will gain the bilby a little exposure and support: obviously, the species actually exists (at least the greater bilby…) and it needs every help to keep it that way. So back to the facts:

Bilbies are rabbit-like marsupials also known by the name rabbit-eared bandicoot, endemic to the arid and semi-arid areas of central Australia. There are two bilby species: the greater bilby (Macrotis lagotis), slowly becoming endangered with around 9000 mature individuals living in natural populations and in captive colonies; and the lesser bilby (Macrotis leucura), already extinct.

The lesser bilby or yallara is relatively unknown to science: most of our knowledge is based on a 1931 description (On mammals from the Lake Eyre Basin) by H. H. Finlayson, who also collected 12 live specimens near Koonchera dune in north-eastern South Australia, where the species seemed to be abundant at that time.

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The lesser bilby went extinct during the 1950s

Date of extinction: The lesser bilby most probably went extinct during the 1950s, but the exact date is unknown. According to the accounts of aboriginal Australians, the species might have survived into the 1960s; but the last physical evidence collected was a less than 15 years old skull found below a wedge-tailed eagle’s nest in the Northern Territory in 1967.

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The bilby on Australian postage stamps from the late 1950s

Range: As the lesser bilby was first described in 1887, there’s very little known about the original range and distribution of the species – at the time of the discovery, lesser bilby populations might have been severely decreased by foreign predators introduced to mainland Australia by European settlers in the late 18^th century. The known range of the species is confined to the Gibson and Great Sandy deserts and the northern half of the Lake Eyre Basin in central Australia.

Habitat: Lesser bilbies used to inhabit arid, sandy dunes and deserts with spinifex vegetation (common collective name of the characteristic, hummock-forming bunchgrasses endemic to Australia), sandhill canegrass, tussock grass and mulga.

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Spinifex – the characteristic vegetation of central arid areas in Australia
©Copyright Dr. Fiona J. Walsh / CC BY 2.0

Description: The appearance of the lesser bilby was very similar to its surviving relative regarding the general shape and proportions of the body, the head and the tail. Bilbies have characteristic, elongated bandicoot muzzle; long rabbit-like ears; and long, furry tails. They have strong forelimbs and claws used for burrowing and digging for food; and they move with a cantering gait with the hind legs moving together and the front legs alternatively, often carrying their tail like a banner.

The fur of the lesser bilby was colored pale yellowish-brown to grey-brown, with lighter fur on its belly, limbs and tail. The body mass of adults was about 300-450 grams, a lot smaller than the greater bilby’s.

Bilbies are strictly nocturnal animals; they spend the daytime sleeping in their 2-3 m deep burrows. The lesser bilby had the habit of temporarily closing the entrance with loose sand while in residence. Bilbies have very limited eyesight – they’re almost blind – but their ears and nose are very sensitive. They are omnivores, feeding on anything from ants, termites and other insects through roots and seeds to small rodents.

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Characteristic features of the bilby: the elongated muzzle and the long, rabbit-like ears

Being marsupials, lesser bilby babies spent a longer period in their mother’s pouch after birth. The females usually had twins and the species probably bred non-seasonally.

Cause of extinction: Competition with rabbits and other animals, degradation and loss of habitat, being hunted for food by aboriginal people and changes in the fire regime are all possible factors that contributed to the extinction of the lesser bilby; but the main reason was that the bilby was defenseless against foreign predators like the foxes and feral cats that were introduced to their ecosystem by humans. The main threats for the still surviving greater bilby are very similar. The national conservation program to save the greater bilby includes monitoring and protecting the wild populations from competitive animals and predators, and captive breeding with reintroduction of small groups into conservation areas of its former habitat.

The national conservation program for the greater bilby also includes captive breeding in zoos.
©Copyright TVGreen on YouTube

The lesser bilby poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Western black rhino – doomed to extinction

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Western black rhino – extinct subspecies of the black rhinoceros

The modern age history of rhinoceroses has been like a rollercoaster, and odds are that’s not going to change in the near future. During the 19-20^th centuries all five extant rhino species were hunted to the brink of extinction: the black rhino population reached a record low of 2400 in 1995, the four other species all had at some point of their story only a few dozen living specimens. Two of them – the Javan and the Sumatran rhino – have each only one population today with estimated 50-80 individuals; both species are critically endangered. Thanks to conservation efforts, by the end of the 20^th century the white rhino and the greater one-horned rhino were able to recover to populations of a few thousand – only to face the danger of extirpation again because of the current surge in poaching to satisfy the increasing demand for rhino horns.

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All five rhino species have been hunted historically for their horns – Indian greater one-horned rhino hunting

Rhino horn has been highly prized and sought after by several cultures for many reasons for over a thousand years, and Asia has been considered the leading consumer for decades, but this recent surge of demand is clearly connected to one country: Vietnam. In the first decade of the 21th century wealthy classes of Vietnam started to regard buying, consuming and gifting rhino horn as a status symbol. This is supported by an underlying belief in health benefits: rhino horn has been used in traditional Chinese medicine for thousands of years – even nowadays, neglecting all scientific evidence of their complete ineffectiveness – but the notion that it is the cure for everything from hangover to cancer is recent, and the latter one is spread by some well-respected Vietnamese doctors.

And as if the dire situation in Vietnam wasn’t enough, in November last year (2018) China announced that they will allow the regulated trade of rhino horn, tiger bones and animal parts of other endangered species used in traditional Chinese medicine again. Currently the implementation of lifting the ban that has been standing since 1993 is postponed because of the international outcry aroused by the announcement – maybe the time should be spent on convincing people willing to give thousands of dollars for a few ounces of rhino horn to choose the much more economical equivalent and chew on their fingernails instead…

Sadly, it is quite certain that four subspecies will not have a future at all: the Indian Javan rhino is thought to be gone extinct before 1925, and after decades of being hunted by poachers three more subspecies eventually went extinct in the first years of the 21th century. Sudan, the last male Northern white rhino, had to be euthanized in March 2018 leaving only 2 females of his subspecies alive in the world; the last known individual of another Javan rhinoceros subspecies (Rhinoceros sondaicus annamiticus) was shot and killed in April 2010 in Vietnam – this subspecies was already thought to be extinct for a while when a tiny population was rediscovered in 1988; and the first victim of the century was the Western black rhino, wiped out completely sometimes in the first decade.

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The last Western black rhinos resided in Cameroon
©Copyright Save The Rhino

Date of extinction: The date and the circumstances of the death of the last Western black rhino are unknown – even the time of the last legit sighting is hard to tell –, but there’s no doubt it was killed by poachers for its horn. A WWF survey in 2001 found five live specimens in Cameroon and reported the possibility of three more unconfirmed individuals. In 2004, a nongovernmental organization (Symbiose) reported that they found evidence of over 30 western black rhinos still living in Cameroon – that quickly turned out to be a lie: the trackers faked rhino footprints to keep their jobs. In 2006, parallel surveys of the WWF, the Cameroon Ministry of Forestry and Wildlife, and a renewed 6 month long field survey of Symbiose conducted on the species’ common roaming ground in Cameroon’s Northern Province failed to find any traces of living specimens. After the usual 5 years waiting period the IUCN eventually changed the status of the Western black rhino from critically endangered to extinct in 2011.

Range: The Western black rhino once used to roam large areas of central and western Africa from south-eastern Niger to South Sudan. The last population lived in Cameroon.

Habitat: Western black rhinos used to inhabit the savanna areas of sub-Saharan Africa; they preferred areas with thick scrub and bushland, gallery woodlands and marshes over the vast grassland.

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Black rhinos roam the vast savannas of sub-Saharan Africa
©Copyright Gerry Zambonini / CC BY-SA 2.0

Description: The Western black rhino (Diceros bicornis longipes) was one of the four subspecies – according to the taxonomical scheme adopted by the IUCN – of the black rhinoceros (Diceros bicornis). With an average of 140-180 cm height at the shoulder, 3-3.75 m body length and 800-1.400 kg weight it was considerably smaller than the other African rhino, the white rhinoceros. The names of both species are misleading as the white rhino is actually grey and the black rhino’s skin varies from brown to grey – they are not truly distinguishable by color.
African rhinos share a common ancestor and are generally quite similar in their appearances – thick skin, massive body with a broad chest, short neck, large head with two horns on the snout, and ears with a relatively wide rotation angle – but besides their size there are minor but very important differences, developed as adaptations to their differing diet and feeding habits. White rhinos are grazers: they eat grass, preferring the shortest grains of the open savanna grasslands; they have a distinctive flat broad mouth, a ‘square’ lip. Black rhinos adapted to browsing: they eat foliage and all leafy parts, branches, shoots and fruits of bushes and smaller trees; they’ve developed a strong, prehensile ‘hooked’ upper lip to grasp the leaves and twigs. The black rhino’s head is also smaller and held higher while white rhinos have a prominent muscular hump to support their larger head.

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The clippers and the lawn-mower: black rhinos have prehensile lips adapted to browsing on leafy plants, white rhinos have square lips adapted to grazing on grass
©Copyright Bernard Dupont / CC BY-SA 2.0 and Martha de Jong-Lantink / CC BY 2.0

Besides their range, Western black rhinos had some less conspicuous features to distinguish them from the other three black rhino subspecies: they had a square based horn, some distinctive chewing apparatus characteristics, and their scientific name – longipes – refers to their longer distal limb segment.

All black rhinos usually spend their time browsing for food in the morning and evening hours and rest during the hot midday period, preferably wallowing in a mud pool to cool down and as a protection against parasites. They regularly visit water holes using the same trails that elephants use – they can live up to 5 days without drinking in drought periods.

Adult black rhinos generally live in solitary, except the mother-calf relation and while mating; young adults frequently form loose associations. Thanks to their deadly horn, thick skin and imposing size rhinos don’t really have any natural predators, except some rare cases of lion or crocodile attack. Black rhinos also have a reputation of being very aggressive, attacking at everything perceived as a threat – even at each other, often causing serious injuries resulting in death. Recent research shows that – in contrary to widespread belief – rhino’s eyesight isn’t particularly poor; although they rely more on their keen ears and excellent sense of smell.

Black rhinos have no mating season. Females have a single calf after a 15 month gestation period; the youngsters stay with their mother for about 2-3 years. Life expectancy in natural conditions is 35-50 years.

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Eastern black rhino baby, a critically endangered black rhino subspecies
©Copyright Tambako the Jaguar / CC BY-ND 2.0

Cause of extinction: At the beginning of the 20^th century around one million black rhinoceroses roamed the savannas of Africa; for most of the century, the population of the Western black rhino was the largest among the subspecies. All black rhino subspecies were heavily hunted in the first decades of the 1900s by ‘sportsmen’ and trophy collectors; with the increasing industrial agriculture farmers and ranchers regarded them as crop pests and decimated their numbers.

Rhino horn has been sought after as a valuable material for special, traditional carved items in the Middle East and Asia; it is still frequently used to prepare the handle of a ceremonial knife called janbiya in Yemen and Saudi Arabia. In the early 1950s, Mao Zedong started to promote so called ‘traditional Chinese medicine’ to counter Western influences: as rhino horn was – absolutely falsely – believed to be able to ‘cure’ several ailments, poaching rapidly increased, and with the dwindling population of rhinos all over Africa and Asia the market value of 1 kg horn reached 50 000 USD. Between 1960 and 1995 98 percent of all black rhino populations were wiped out.

By the 1980s there were only two countries left in Africa with Western black rhinos: Cameroon had around 110 and Chad around 25 individuals living in their territory, with no known specimens in any zoos. The Chad population was eliminated within the next decade; and by the end of the century Cameroon had only 10 Western black rhinos, partly living in isolation without any hope to find each other and start breeding.

The WWF was the only organization coming up with a preservation plan to save the Western black rhino (1999), but unfortunately in lack of local conservation capacity and government commitment the program has never had a chance to be carried out, and the Western black rhinoceros was wiped out from the planet.

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With the recent surge in poaching all rhino species are in danger
©Copyright Dolf Botha / CC BY-NC-ND 2.0

The Western black rhino poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Pinta Island tortoise – architect of Galápagos

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The Pinta Island tortoise is one of the giant Galápagos tortoise species

The Pinta Island tortoise (Chelonoidis abingdonii) belongs to the Galápagos tortoises: the species complex of Chelonoidis nigra comprises one of the two still extant giant tortoise populations on the planet – the other one being the Aldabra giant tortoise (Aldabrachelys gigantea), native to a remote atoll of the Seychelles Islands in the Indian Ocean.

The common ancestors of the Galápagos tortoises arrived to the volcanic archipelago from mainland South America 2-3 million years ago, drifting 600 miles to the west with the Humboldt Currents. They colonized the oldest, easternmost islands of San Cristóbal and Espanola; then later they dispersed throughout the younger, westerly located islands of the archipelago – the process was probably parallel with and highly influenced by the continuing volcanic events and formation of the islands. They eventually inhabited 9 islands and developed into 14 variations – 11 islands and 16 variations, if we count the 2 disputed species of Rábida and Santa Fe Islands – that differ not only genetically but also in appearance and behavior.

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Most of the extant Galápagos tortoise populations are endangered

Due to massive exploitation mainly for their meat and oil by whalers and buccaneers in several waves from the 16^th century, the numbers of tortoises declined from over 250 000 to around 3000 in the mid 1900s, when conservation programs were started to preserve and restore the rapidly demising unique ecosystem and wildlife of the archipelago.

The taxonomic status of the different Galápagos tortoise races hasn’t been fully resolved yet and the conservation status of the populations keeps also changing as continued research of the remaining wild and captive populations, DNA analysis and other modern scientific methods have revealed new information and surprising events in the last decades. Just in February this year (2019), a lonely female tortoise was discovered on Fernandina Island – a population (Chelonoidis phantasticus) that was originally known from a single specimen and thought to have gone extinct a century ago.
As of today, most of the 12 extant species (with at least one live purebred specimen) are assessed critically endangered or endangered, the 2 disputed species are surely extinct, and there are chances that two species – the Pinta and the Floreana (Chelonoidis nigra) populations – considered currently extinct may have unlocated live specimens or could be revived by interbreeding programs of hybrid specimens aimed to restore the approximate genetic constitution of these species.

Date of extinction: The Pinta Island tortoise was assumed to be extinct in the mid 20^th century until 1 December 1971, when a lone male was found on the island. He was named Lonesome George and became a symbol for conservation efforts not only for the Galápagos tortoises but for all endangered species around the world. As despite all efforts no other individuals of his species were discovered either in the wild or in captive populations of the world’s zoos, with Lonesome George’s death on 24 June 2012 the species was thought to be extinct forever.

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Lonesome George, the last known Pinta Island tortoise
©Copyright 3rdfloor / CC BY-NC-ND 2.0

However, there’s still some hope for bringing back the Pinta Island tortoise from extinction once again. In 2008, an expedition of researchers reported that they found 17 young first-generation Pinta hybrids in the Volcano Wolf (Chelonoidis becki) tortoise population on Isabela Island. As Galápagos tortoises can have a lifespan of 100 years in the wild, the pure Pinta parent of these hybrid specimens could still be alive somewhere on Isabela Island.

Range: As its name suggests, the Pinta Island tortoise originally used to be endemic exclusively to Pinta Island (also known as Abingdoni Island), the northernmost major island of the Galápagos archipelago.
The most probable explanation for the presence of the Pinta hybrids on Isabela is that whalers and pirates regularly used to drop large numbers of tortoises – collected from other islands of the archipelago – in Banks Bay, near Isabela Island to lighten the burden of their ship. Apparently, many of these tortoises managed to get to the shore and survived; producing purebred specimens, and also hybrids by mating with the local Volcano Wolf population. This theory is supported by the fact that researchers have also found Floreana Island hybrids – the species was declared extinct in 1846 – in the same population.

Habitat: Pinta Island tortoises migrated seasonally up and down the volcano between two characteristic habitat zones of the island in response to changes in the availability and quality of the vegetation. In the dry season, they inhabited the meadows of the native Scalesia tree forest of the humid zone of higher elevations limited only to a small area of the island. In the wet season, they migrated to the warmer arid lowland zone that is primarily characterized by cacti, scattered deciduous trees, shrubs, herbs and xerophytic species; but turns into a grassy plain as the rain arrives. As tortoises used the same routes for many generations, the paths they’ve trodden into the undergrowth remained clearly recognizable even several decades after the last tortoises were seen on the island. This seasonal migration up and down the volcano is typical also to other Galápagos tortoise populations living on islands that are high enough to have a humid zone.

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Opuntia forest in the lowland arid zone and meadow of the native Scalesia forest of the humid highland zone on Santa Cruz Island
©Copyright Dallas Krentzel / CC BY 2.0 and Andy Kraemer / CC BY-NC 2.0

The indigenous flora and fauna of most islands of the archipelago has suffered major losses and has undergone degradation during the centuries because of the invasive species introduced by humans. On Pinta, after releasing goats on the island in 1959, the native vegetation went through a long period of degradation as a consequence of the intense grazing pressure caused by the rapidly increasing feral goat population. During the 1970s, a complex conservation program was started to restore the original ecosystem of the island. The first step – the complete eradication of the feral goats – was achieved in 1999, resulting in Pinta being one of the islands with almost no exotic species. Fortunately the vegetation has been recovering rapidly since – without any loss in Pinta’s endemic plant species – but some indicators show that the biological diversity and the healthy structure of the habitat can’t be completely restored without the presence of the giant turtles.

Research shows that Galápagos tortoises are keystone species of their ecosystem, as they have a major impact on the structure and composition of the vegetation. They maintain open areas within forests and dense vegetation by grazing and by simply moving through their environment as minor bulldozers, thus – by thinning the understory vegetation and letting more sunlight in – they provide suitable habitat for many endemic plant species. They also play an important role in the dispersal and germination of seeds: they eat large amounts of plant matter that they deposit during their long distance migrations.

In 2010, 39 sterilized hybrid tortoises were released to Pinta to help to restore the ecosystem to its original condition before human’s arrival. Hopefully someday the conservation efforts to revive the Pinta Island tortoises will be successful and there will be a breeding population on the island again.

Description: Galápagos tortoises are the largest living terrestrial turtles, though their size varies across the islands/races significantly. Male individuals of the larger bodied species can reach up to 1.85 meter length and weigh over 400 kg, but the smallest one – native to Pinzón Island (Chelonoidis duncanensis) – measures only around 75 kg and 60 cm. Regarding its size, the Pinta Island tortoise was probably closer to the smaller end of the scale: Lonesome George weighed around 85-90 kg.

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Galápagos tortoise with domed shell, the ancient carapace form characteristic to species from more humid islands
©Copyright Aki Sasaki / CC BY-NC-ND 2.0

The carapace morphology of the Galapagos tortoises is quite diverse, the species can be distinguished based on the shape and details of their shell. There are two main varieties: the domed shell – probably the original form of their ancestor – is characteristic for populations inhabiting larger islands with humid highlands where abundant vegetation is available easily near the ground all year; the saddleback form with proportionally longer necks and limbs is common in smaller islands where the arid zone is the main habitat, providing more limited resource of food in the dry season. The raised front opening of the carapace with the longer neck is thought to be an evolutionary response that enables the tortoise to extend its head up higher to reach the leaves and shoots of trees and cactus pads. Domed tortoises tend to be also larger in size than saddle-backed species. The Pinta Island population belonged to the saddle-backed variations: as Pinta is not high and large enough – maximum altitude is 777 meters, area 60 km2 – to have a fully developed, rich cloud forest of Scalesia; the island’s humid zone is rather limited in area and native tortoises had to adapt mainly to the limitations of the available vegetation in the arid zone.

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Galápagos tortoise with saddleback shell, characteristic to populations from more arid islands like Pinta Island
©Copyright Andy Kraemer / CC BY-NC 2.0

Galápagos tortoises are herbivores; feeding huge amounts of grasses, leaves, cactus pads and every kind of fruits available. They have a very slow metabolism and are able to store significant amount of moisture and fat in their body and thus endure longer periods without water or food. Being cold-blooded animals, they adapt their daily routine to the ambient temperature of their environment. They bask 1-2 hours in the heat of the sun before they start their foraging tour; and in the hot season they have a ‘midday nap’ resting in the shade or half-submerged in muddy wallows trying to keep cool.

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Galápagos tortoises resting and cooling in a muddy pool

Galápagos tortoises mate primarily during the hot season – the process is quite cumbersome because of the huge, heavy shells – then females migrate to dry, sandy nesting areas to lay their eggs. The female tortoise prepares a nest by arduously digging a hole with her hind feet and seals the nest with a muddy plug above the hard-shelled, billiard ball sized eggs. For saddle-backed tortoises the average clutch size is 2-7 eggs, hatching after a four to eight months incubation period. Hatchlings measure only about 50 g and 6 cm; it can take several weeks for them to dig their way to the surface where they face severe hazards of the unfriendly environment. However, once they manage to survive the first 10-15 years, they grow big enough to have no natural predators and can easily live over 100 years.

At least that’s how it was before human’s arrival…since then, introduced feral rats, cats, dogs and pigs have been a constant threat to the eggs and young tortoises. On Pinzón Island, most of the hatchlings had been killed by rats for centuries until only about 200 old adults remained. In 2012, the invasive rodent population was eradicated and 2 years later the first newly hatched tortoises were reported from the island…

Cause of extinction: Ironically, the major cause of the demise of the Galápagos giant tortoises was their amazing adaptation that once helped their ancestor to reach the archipelago on the currents and colonize the islands – the ability to survive without water of food for up to a year. From the discovery of the archipelago in the 16^th century, whalers, fur hunters and pirates frequently used it as a base for restocking; taking hundreds of tortoises on board as living meet and water supplies for their long journeys. Exploitation increased in several waves during the centuries; in addition, the original ecosystem of the archipelago also had to face the usual threats islands experience with human invasion: introduction of alien predators (rats, cats, dogs, pigs), grazing competition (goats, cattle), and the degradation and loss of habitat caused by the growing agricultural activity.

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Hopefully the still extant Galápagos tortoise populations will HAVE a future…

The Pinta Island tortoise poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The little Mariana fruit bat – fanihi of Guam

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The little Mariana fruit bat is an extinct megabat from Guam

The little Mariana fruit bat – also known as Guam flying fox – is one of the four already extinct species of megabats or fruit bats (the family Pteropodidae).

These bats are found in tropical and subtropical areas around the world, both on islands and mainlands. They differ from ‘regular’ bats in a few important characteristics: they are herbivores, not insectivores; they rely on their keen senses of sight and smell to navigate, not echolocation (though there are some exceptions); and they are relatively larger in size.

The name fruit bat refers to the fact that these animals’ primarily food sources are different kinds of fruits supplemented with nectar and pollen from flowers, with shoots, buds, seed pods and other parts of plants. By contributing to seed dispersal and flower pollination they play an important role in their ecosystem, some of them – like the little Mariana fruit bat – are keystone species in forest regeneration of their regions.

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Fruit bats are important species in forest regeneration
©Copyright shellac / CC BY 2.0

Date of extinction: The last recorded sighting of the little Mariana fruit bat dates to 1968, when a female was shot and killed by hunters at the northern part of Guam while her juvenile managed to escape. Intensive surveys on the island’s fruit bat colonies couldn’t locate any single specimen of the species since that so most probably it went extinct during the 1970s.

Range: The little Mariana fruit bat was endemic to the island of Guam, located in the Marianas archipelago of the Pacific Ocean.

Habitat: Most probably the limestone forests typical in the northern part of Guam. This forest type has a 8-15 meters high canopy and a relatively sparser understory vegetation, with some scattered trees emerging above the main canopy.

Description: The little Mariana fruit bat (Pteropus tokudae) was first identified and described in 1934 by G. H. H. Tate after discovering the species on an expedition. According to his account, the newly discovered species bore a striking morphological resemblance to the Chuuk flying fox (Pteropus pelagicus), a fruit bat endemic to Micronesia.

The little Mariana fruit bat had a body length of about 150 mm, a wingspan of 650-700 mm and a body weight of around 150 gram. The wings and the abdomen were brown with some whitish hairs, the mantle and the sides of the neck were brown to light gold. It had prominent ears, a greyish-yellowish brown head with dark brown throat and chin.

There’s very little known about the food preferences, nesting and roosting habits, and reproductive pattern of the species. Most likely they fed on fruits and flowers from evergreen shrubs of the limestone forest, thus – as fruit bats are the only native frugivorous mammals in the southwestern Pacific – they played a key role in forest regeneration of the area by contributing to seed dispersal and flower pollination.

They were observed roosting with the larger Mariana flying fox (Pteropus mariannus), an endangered, medium-sized megabat found on a range of Pacific islands from Japan to Guam.

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The endangered Mariana fruit bat (Pteropus mariannus)
©Copyright Jennifer Campbell-Smith

Cause of extinction: Little Mariana fruit bats – as every other fruit bat, known as ‘fanihi’ in the Chamorro culture of the Marianas – are considered a delicacy and were frequently hunted by native people of Guam. Although there’s no data available about the size of the population, the Guam flying fox was always regarded as rare by hunters and collectors; and with the introduction of firearms to the island the decline of the species accelerated.

Overhunting for food by humans was the main reason, but probably other factors also played a role in their extinction: the degradation and alteration of native limestone forests and the introduction of foreign predators to the ecosystem of the island by humans. The most probable ‘suspect’ is the brown tree snake (Boiga irregularis) – an invasive species that was brought to Guam after WW2 and is responsible for extirpating many of the native bird species of the island.

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The brown tree snake might have been a factor in the extirpation of the little Mariana fruit bat
©Copyright Pavel Kirillov / CC BY-SA 2.0

The little Mariana fruit bat poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Steller’s sea cow – the last of the Pleistocene megafauna

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Steller’s sea cow – a surviving giant of the Pleistocene

The Steller’s sea cow was one of the last survivors of the megafauna of the Pleistocene to die out in our era. The giant marine mammal was discovered in 1741 by Georg Steller – naturalist of the expedition led by Danish explorer Vitus Bering on the commission of the Imperial Russian government to chart the route between Siberia and Kamchatka – when their ship wrecked on an uninhabited island on the way back to Russia. The sea cow population was confined to the waters surrounding two small islands – the newly discovered species was completely extirpated during the following decades by expeditions of the flourishing Pacific maritime fur trade. The demise of the sea cow was so rapid that in fact everything we know about its appearance and habits is based on the detailed accounts of Steller from his posthumous published work: De bestiis marinis – The Beasts of the Sea, and the few dozen skeletons that were found from the mid 1800s until today.

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Model of the Steller’s sea cow based on descriptions and skeletons; a reconstruction made for the Skin & Bones project of the Smithsonian’s National Museum of Natural History by
©Copyright Diana Marques

Date of extinction: Johann Friedrich von Brandt, director of the Russian Academy of Sciences concluded based on reports from fur hunters following Vitus Bering’s route to Alaska that the Steller’s sea cow was extinct by 1768, only 27 years after it was discovered by the Bering expedition.
However, there were some reports of alleged sightings dating after the official extinction date, even from the mid 20^th century.

Range: At the time of its discovery, the Steller’s sea cow had only one last population: in the surrounding waters of the Bering and Copper Islands, two members of the Commander Chain between the Aleutians and the Kamchatka Peninsula.
Later discovered evidence of bone fragments proves the existence of another population in the northern Bering Sea at St. Lawrence Island around the 9-10^th centuries; and based on bone fragments and accounts of Aleut people it is probable that another population persisted into the late 18^th century at the Near Islands (western Aleutian Islands).
Fossil finds from the Pleistocene show that before the Ice Age sea cows were probably ubiquitous along the edge of the Pacific from Japan to the Baja Peninsula.

extinct steller’s sea cow grazing kelp forest hunting

Illustration of the Steller’s sea cow grazing on kelp
©Copyright Encyclopaedia Britannica, Inc

Habitat: The Steller’s sea cow used to inhabit the cold shallow waters along the shores.

Description: Steller’s sea cows (Hydrodamalis gigas) were large sirenians, members of the once-diverse family Dugongidae. Their closest living relatives are the dugong and three manatee species, but instead of the warm tropical seas they adapted to living in frigid Arctic waters. Their huge size – adults grew to be 8-9 m long, weighing up to 10 tons – their thick blubber and outer skin were effective adaptation methods to conserve the heat of their body in the icy sea and to prevent injury from the sharp rocks of the shallow waters.

A baby Florida manatee (Trichechus manatus latirostrus) drinks milk from its mother. Three Sisters Spring, Crystal River, Florida, United States of America.

Manatees are sirenians closely related to the extinct Steller’s sea cow
©Copyright Alex Mustard

They were obligate algivores eating seaweed; but being unable to completely submerge, their food source was reduced to kelp and seagrass species inhabiting the coastal waters, with their canopy not deeper than 1 meter below the tide. They could hold their breath for a few minutes under water and the inside of their flippers was covered with bristles to anchor them down and prevent them from being swept away by strong waves. The flippers and the forked tail fluke were used for swimming and walking in shallow water.

The sea cow’s snout and mouth were perfectly adapted to grazing on kelp: the snout pointed downwards, with large and broad upper lips extending beyond the lower jaw. Instead of teeth they had white bristles on their upper lip, with some of them protruding from the muzzle; and two keratinous plates in their mouth, used for chewing.

sea cow dugong

Portrait of a dugong, the closest living relative of the Steller’s sea cow
©Copyright Laura Dinraths

Sea cows were highly social animals, probably monogamous. They lived in small family groups, guarded and helped each other and protected their calves against predators. Females had one calf after a more than one year long pregnancy period.

Cause of extinction: The rapid demise of the Steller’s sea cow population of the Commander Islands was apparently the consequence of overhunting for their tasty meat and valuable subcutaneous fat by European and Russian sailors and fur traders. The populations of the Aleut and St. Lawrence Islands were wiped out by native people for the same reasons.

However, recent studies (James A. Estes) based on modern methods of mathematical simulations to model indirect community interactions prove that the extinction of the Steller’s sea cow at the Commander Islands would have been inevitable anyway as a consequence of the ongoing overkill of sea otters by Russian and Aleut hunters after the onset of the Pacific maritime fur trade in the 1740s.

endangered sea otter portrait cute on back

The sea otter is a keystone species in the trophic cascade of the kelp forest
©Copyright Robin Agarwal / CC BY-NC-NC 2.0

Several observations during the 20^th century in different areas of the Northern Pacific showed evidence that sea otters are key species in the trophic cascades of the kelp forest: they maintain the ecological equilibrium by limiting the number of sea urchins, one of their main food sources. Sea urchins are herbivorous animals thriving in kelp forests: without sea otters their population increases rapidly, creating kelp-free dead zones and leaving other herbivores with nothing to eat. The elimination of sea otters from the Commander Islands ecosystem caused a chain reaction reshaping the whole habitat: with the decline of the kelp forest the environmental carrying capacity for sea cows drastically reduced – the species most probably would have starved to extinction in a few decades.

The example of the Steller’s sea cow has major significance as it supports the long debated hypothesis about the sudden extinction of the New World’s megafauna at the turn of the Pleistocene/Holocene eras that the directly caused extinction of a few keystone species responsible for maintaining the balance of their ecosystem may have resulted in the coextinction of other species. This theory explains the sudden disappearance of several other giant species: for example, the Haast’s Eagle vanished from New Zealand along with its prey, the giant moa, that went extinct about a hundred years after the Maori landed on New Zealand.

Haast eagle preying on giant moa New Zealand Pleistocene megafauna extinction

Pleistocene giants from New Zealand: the Haast’s eagle preying on a giant moa
©Copyright Nick Keller

The Steller’s sea cow poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Bali tiger – hunted to extinction

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The Bali tiger – the first tiger species completely extirpated by humans

Tigers once used to roam the wide regions of Asia from Eastern Anatolia to the coast of the Sea of Japan, from the southern foothills of the Himalayas to the Sunda Islands of Sumatra, Java and Bali. At the beginning of the 20^th century the number of wild tigers was estimated around 100 000 globally – in 2015, less than 4000 individuals remained in small, isolated populations restricted to around 5-7 % of their historic range.

Based mainly on their geographical range there were 9 tiger subspecies distinguished and recognized until the end of the 1990s; four of them – the Javan, the Caspian, the South China and the Bali tigers – already driven to extinction in the wild by humans during the century.

In 2017, the Cat Classification Task Force of the IUCN Cat Specialist Group revised felid taxonomy: based on combined analysis of skulls, morphological, ecological and molecular traits tigers are now divided into two subspecies: Panthera tigris tigris with 6 populations on mainland Asia, and Panthera tigris sondaica with 2 already extinct (the Bali and the Javan tiger) and one critically endangered (the Sumatran tiger) populations on the Sunda Islands.

critically endangered sumatran tiger Panthera tigris sondaica

The critically endangered Sumatran tiger is the only extant population of the subspecies Panthera tigris sondaica
by Bernard Spragg

The number of tigers living in captivity is estimated to be around 10 000 individuals worldwide, most of them are of mixed genetics. Many of them are privately owned and kept as pets (mainly in the US and China).

Date of extinction: The last known Bali tiger – an adult female – was shot and killed by Dutch hunters at Sumbar Kima, West Bali, on 27 September 1937. There have been a few unconfirmed reports of tigers from West Bali in the 1960s, but as subsequent surveys in the late 1950s and in 1960 found no evidence of extant tigers on the island, these individuals were most probably stray Javan tigers swimming the 2.5 km wide Bali Straits from the Baluran Reserve on Java. By most experts, Bali tigers are considered to have gone extinct between the end of World War II and the 1950s – they were the first tiger species completely extirpated.

Balinese tiger extinct killed shot hunting colonist dutch East-Indies

A Bali tiger shot around 1916
by Vincent Nijman via researchgate

Range: Endemic to the island of Bali in the Sunda Islands.

Habitat: The Bali tiger used to live in the mangrove forests and savannah of the island.

Description: The Bali tiger (Panthera tigris balica, now Panthera tigris sondaica) was the smallest tiger of all variations: males were about 220-230 cm long from head to end of tail and weighed about 90-100 kg, females were about 10 % smaller. Their fur was the darkest orange of all tiger races, but with fewer stripes and black spots scattered between them.

sumatran tiger cub jacksonville zoo tiger conservation program

Sumatran tiger cub in the Jacksonville Zoo
©Copyright Valerie/ CC BY-NC-ND 2.0

The main prey of the Bali tiger was the Javan rusa, a deer species common on the islands of Indonesia. Based on the size of their required hunting territory, the tiger population of Bali was probably never more than a few hundred.

The Bali tiger is an important part of the folklore and magic of the island’s people, often appearing in folk tales and in traditional arts. One of the five forms of the traditional Barong mask dance representing the eternal battle between good (Barong) and evil (Rangda) is called barong macan (tiger barong). Barong is the king of the spirits in Balinese mythology, the mask of the Barong macan dancer is shaped like a tiger’s head.

barong macan mask Balinese tiger dance

Balinese Barong macan tiger mask, mid 20th century
©Copyright Catawiki

Cause of extinction: Tiger hunting used to be a popular sport of the Dutch colonists of the Indonesian archipelago. After they gained political and economical control over Bali at the turn of the 20^th century, hunting trips were organized for tourists and ‘sportsmen’ to hunt tigers on the island and the nearby island of Java.

Bali tiger hunting party extinct baron Oscar Vojnich

Hungarian hunter baron Oscar Vojnich posing with a dead Bali tiger, November 1911

Meanwhile, the plantations of the intensive wet-rice agriculture occupied more and more area on the slopes of the volcanoes and the narrow alluvial strip around the island, causing significant loss and fragmentation of the natural habitat of the tigers. In 1941, a game reserve (today West Bali National Park) was established in the western part of the island but the area was too small and fragmented to save the Bali tiger from extinction. In fact, today there’s no adequate area of natural habitat on the island of Bali to host tigers…

The Bali tiger poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Cuban red macaw – parrots of the Caribbean

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The Cuban red macaw – Ara tricolor

The Cuban red macaw (Ara tricolor) is one of the several extinct macaw species that once used to live in the Caribbean area. As all these species were driven to extinction by humans before they could have been properly described, identified and classified by modern science, there’s an ongoing debate among ornithologists about the exact number of species, their origin, range and taxonomic relations.

Based on the various theories of the experts there could have been as many as 13 different macaw species endemic to the Caribbean islands. Many of the suggested 13 species are only hypothetical species, mainly based on old descriptions and illustrations – hopefully DNA analysis of fossil finds and further examination of contemporary sources can resolve the identity of these birds one day. There are only three Caribbean macaws known from actual modern physical remains: the Cuban red macaw is one of them.

Illustrations from Walter Rothschild’s book ‘Extinct birds’ (1907): the Cuban red macaw (Ara tricolor) and three hypothetical species: Ara erythrura, Ara martinicus and Ara erythrocephala

Cuban-red-macaw-Caribbean-islands-ara-tricolor

Martinique-macaw-Caribbean-ara-erythrura-hypothetical-macaw

Martinique-macaw-orange-bellied-macaw-ara-martinicus-hypothetical-species

red-headed-macaw-Jamaican-green-and-yellow-macaw-ara-erythrocephala-hypothetical-species

Date of extinction: As between 1844-56 several subsequent hurricanes destroyed their habitat and scattered the remaining population, by the mid-19^th century the species was becoming rare on the main island of Cuba. The exact date of the extinction of the Cuban macaw is unknown: based on the accounts of Cuban naturalist Juan Gundlach the last specimens could have survived until about 1885.

Range: Historical records and contemporary accounts show that macaws had been transported and traded regularly between the Caribbean islands and the mainland (South America) both in prehistoric and modern times by Native Americans, and by European sailors and settlers after their arrival in the 15^th century; therefore, verification of the original range of macaw species can be rather uncertain. The Cuban red macaw was endemic to the main island of Cuba and probably the nearby Isla de la Juventud.

Habitat: The Cuban red macaw used to inhabit the mixed woodland-grassland ecosystem with scattered trees (open savanna) of the central and western part of the island and the gallery forests of these areas. Many reports in the 18-19^th century came from the huge Zapata Swamp located southeast of Havana – today, this area is the best preserved wetland in the Antilles and part of the Ciénaga de Zapata Biosphere Reserve and wildlife sanctuary.

Description: With about 50 cm length, the Cuban red macaw was one of the smallest Ara species. Coloration of its plumage ranged from the red on the forehead through orange and yellow on the neck to brownish-red and purplish blue to the back, the wings and the tail. They had a distinct, white, unfeathered patch around the eyes. Male and female looked similar, as with other macaw species.
Based on the similar distribution of red and blue in their plumage, the white patch around the eyes, their adjoining ranges, and a shared feather mite, one of the closest extant relatives of the Cuban red macaw is probably the scarlet macaw (Ara macaw).

scarlet-macaw-Ara-macaw

There’s little known about the behavior and breeding habits of the Cuban macaw. Their main food sources were probably fruits, seeds and shoots of palms and the chinaberry tree.

Cause of extinction: Several factors have contributed to the extinction of the Cuban red macaw. In fact, the main threats for all parrot species were and are very similar; they are often among the first species to be exterminated from a given locality, especially islands.

great-green-macaw-Buffons-great-military-macaw

The great green macaw (Ara ambiguus), a close relative of the Cuban macaw is listed as endangered on the IUCN Red List due to habitat loss, hunting and trade.
©Copyright Steven Metildi

Parrots were frequently hunted and killed for food by Amerindians in the West Indies – there are even reports about macaws and parrots being held captive to fatten them. Cuban macaws had a reputation of being especially easy to hunt because of their ‘boldness’ (or stupidity) – the arrival of the European sailors and the introduction of firearms to the islands accelerated the dwindling of the population.

Another main threat was trade: besides being kept as pets locally by Native Americans and colonists, macaws were captured and sent to Europe as popular, valued cagebirds for zoos and private collectors – several of the preserved 19 skins of the Cuban red macaw originate from captive specimens. Collectors usually obtained young chicks by felling the trees with their nest, thereby also destructing the species’ breeding habitat. This practice is still common in Cuba and greatly affects the populations of the surviving parrot species.

As more and more natural lands were cultivated in association with human population growth, habitat destruction also contributed to the Cuban red macaw’s extinction. They were also persecuted as crop pests because they fed on fruit trees.

Once macaw populations were restricted to a few relatively small areas of fragmented habitat, direct hits by storms that would have had no effect on a healthy population proved to be detrimental. In addition, exotic diseases of imported pets and domestic fowls were also very dangerous to the indigenous parrot species that had little or no resistance against them.

The Cuban red macaw poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The great auk – extinct eponym of the penguins

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The great auk – the eponym of the penguins

Nowadays when we mention penguins everybody thinks of the flightless aquatic birds of the Antarctic proudly wearing their tuxedos. Few people now that the original penguin – the eponym of these popular birds – was the great auk (Pinguinus impennis): an already extinct species that once used to be fairly well-known by the people of Europe and North America. Actually, taxonomically the great auk and penguins are only distantly related; but when exploring the seas of the Southern Hemisphere European sailors named the newly discovered species due to their physical resemblance to the great auk. The two taxa are widely considered as an example of convergent evolution and ecological corollary.

Date of extinction: The nesting colonies of the great auk had been nearly eliminated by humans by the 16^th century along the European side of the Atlantic and by the end of the 18^th century along the American coast. One last nesting colony remained on a remote, inaccessible islet near Iceland – in 1830, the Great Auk Rock was destroyed by a volcanic eruption. The birds moved to the nearby Eldey Rock, where the colony quickly diminished – the adult specimens and their eggs were collected for museums for preservation and display. The last pair incubating an egg was killed on 3 June 1844. The last confirmed sighting of a living great auk dates from 1852, from the shores of Newfoundland.

extinct-great-auk-Errol-Fuller-Last-Stand

Range: Once great auks were fairly common in the coastal area on both sides of the North Atlantic, the estimated maximum population was in the millions. They inhabited mainly the colder coastal waters from Greenland and Norway to Canada and Great Britain, occasionally reaching even the warmer seas of the Iberian Peninsula and Florida.

Habitat: Great auks spent most of their lives in the sea, foraging on smaller fish – they only left the water for land when breeding. They nested in very dense colonies on remote rocky islands with rich feeding areas around them, where the sloping shorelines provided easy access to the sea. It is believed that the great auk never had more than 20 breeding colonies – some of the known localities were Funk Island near Newfundland, St. Kilda off Scotland, Geirfuglasker near Iceland, The Gulf of St. Lawrence and Eldey Island.

great-auk-specimen-glasgow museums collection

Description: Great auks were large, flightless seabirds in the family Alcidae; standing about 75 to 85 cm tall and weighing up to 5 kg. In overall appearance they looked similar to their smaller living relatives, the razorbills. Male and female were similar in plumage, with probably a small difference in size. They appeared chubby due to a thick layer of fat necessary for keeping their bodies warm in the cold water. The adult birds had black plumage dorsally, with white breasts, bellies, and undertail-coverts, with some seasonal and ontogenic differences. Their wings had a white trailing edge and in breeding plumage there was a large white patch in front of each eye, which was replaced in the non-breeding period by a broad, white band and a grey row of feathers extending from the eye to the ear. Their bills were robust and ridged and curved downward at the top. The reduced wings were only about 15 cm in length and were used to propel themselves underwater during dives.

Between late May and early June female auks used to lay one egg each year. The egg had a characteristic, elongated shape with a marbling pattern of varying black, brown or grayish spots and lines on a yellowish base. The size of the egg averaged around 12-13 cm length and 7-8 cm across at the widest.

great-auk-eggs-photo-painting

The characteristic egg of the great auk: an old photograph from 1844 from The Auk, the quarterly journal of the American Ornithologists’ Union on the left
and a colored lithograph by F. W. Frohawk from 1888 on the right ©Copyright Wellcome Collection / CC BY 4.0

Great auk chicks had grey down, the black neck of the juveniles was mottled white. They had white rings around the eyes but instead of the white patch of the adults they had a grey eye line extending to below the ears.

Great auks were excellent swimmers, able to evade capture by people in boats. They were able to dive to great depths (even around 100 meters) and could hold their breath for 15 minutes – that is longer than what a seal is capable of. When on land, they walked slowly and awkwardly with short steps.

Turnaround video of a stuffed great auk and its closest living relative, a razorbill
©Copyright Naturalis Biodiversity Center

Cause of extinction: The story of the extinction of the great auk is one of those stories about the endless stupidity, greed and selfishness of humanity that leave you with incomprehension and seething with anger. In comparison to other bird species that went extinct around the same time, the steps leading to the total disappearance of the great auk are quite well documented – especially the last, brutally cruel acts of the 19^th century. If you are interested in the details I recommend you reading Errol Fuller’s excellent book: The Great Auk: The Extinction of the Original Penguin.

To summarize: after being intensively hunted by humans at least from the 8^th century – mainly for food and fishing bait – this species was eliminated eventually to make pillows from its down, and to provide stuffed specimens and eggs as collectibles for rich Europeans and museums.

A few years ago, an international team of scientists began a discussion about the possibilities of reintroducing the great auk into its former natural habitat by recreating the species using DNA extracted form fossils or preserved organs (edited into the cells of the closest living relative, the razorbill) and implanting fertilized embryos into a bird big enough to be capable to lay a great auk egg.

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Life-sized great auk statue by artist Todd McGrain on the Reykjanes headland (Iceland), one of the last known locations of the bird
©Copyright Chuck Reback

The great auk poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Siamese bala shark – a victim of aquarium trade

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Siamese bala shark – also known as burnt-tailed barb

These days, with all the heavy pollution of our waters from different sources and the massive overfishing with industrial methods, capturing for international aquarium trade might be the least concern threat for most fish species, but for some freshwater fish endemic only to a limited area of one or two river basins it can be a deciding factor in survival or extinction. The Siamese bala shark (Balantiocheilos ambusticauda) a.k.a burnt-tailed barb happens to be one of these species – this freshwater cyprinid fish is listed on the IUCN Red List as critically endangered, possibly extinct in the 1970s.

Date of extinction: The last confirmed sighting of the species in the wild dates from 1974, although well-known Thai freshwater fish explorer Kittipong Jaruthanin reportedly found some specimens in 1986 in their natural habitat at the Cao Phraya River near Bangkok. All surveys carried out since the 1980s covering the whole confirmed range of the species failed to find any specimens and there are no living specimens in captivity either. Given the estimated generation length of around 10 years, the Siamese bala shark is most probably extinct.

Range: Authentic specimens are known only from Thailand, from the river basins of the Mae Khlong and Chaou Phraya. Reports from the Mekong basin in Cambodia, Vietnam and Laos were most probably false – the species can be easily mistaken for the closely related B. melanopterus.

Habitat: The Siamese bala shark used to inhabit freshwater wetlands (lowland riverine and marshland floodplains). There’s very little known about the needs and life cycle of the species.

Description: Taxonomically the Siamese bala shark (Balantiocheilos ambusticauda) is not a true shark, the common name only refers to the body-shape and fins of the species strongly resembling the characteristic shape of sharks.

Silver-shark-closely-related-to-siamese-bala-shark

Balantiocheilos-melanopterus-aquarium

The silver shark or tricolor sharkminnow (Balantiocheilos melanopterus) is an endangered species
©Copyright Raimond Spekking / CC BY-SA 3.0 (via Wikimedia Commons)

The Siamese bala shark is closely related to the well-known aquarium fish Silver shark (Balantiocheilos melanopterus, an endangered species) and was recognized as a separate species only in 2007, based on a holotype collected in 1967.

According to Biotaxa/Zootaxa: “Balantiocheilos ambusticauda…can be distinguished from its only congener, B. melanopterus, in having a shorter snout (27.5–33.9% HL vs. 33.2–39.1), posteriorly directed grooves at rictus curved (vs. straight), and narrower black margins on the pelvic and anal fins (on distal third or less vs. on distal half or more).” Bala sharks will grow to a maximum length of around 35 cm.

To my best knowledge, all photographs on the internet labeled as Siamese bala shark show the Silver shark in fact.

Video of a silver shark shoal in aquarium By Paul Talbot http://www.majesticaquariums.com.au

Cause of extinction: Besides overfishing for international aquarium trade up until the 1980s, the changing agricultural methods applying more and more insecticides and chemical fertilizers and the building of dams for water management caused the extinction of the Siamese bala shark by decreasing the habitat of the species and causing significant deterioration in water quality.

The Siamese bala shark poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.

The Madeiran large white butterfly – last seen in the 20th century

madeiran-large-white-butterfly

Madeiran large white butterfly

The Madeiran large white butterfly is one of the many species that were last seen in the 20^th century. We can’t absolutely be sure about the extinction of these species – the IUCN Red List assesses them usually as critically endangered, possibly extinct – but in the case of this butterfly unfortunately it’s rather certain that there is no hope anymore: since the end of the 1980s there were several searching attempts organized to find living specimens on the relatively small island of Madeira – all unsuccessful.

Female Madeiran large white

male Madeiran large white

Date of extinction: Many sites list 1977 as the date of the last confirmed sighting – in fact, the last specimens of the species were collected in 1986 (Antonio Aguiar).

Range: Endemic to the Macaronesian island of Madeira.

Habitat: The Madeiran large white used to live in the laurisilva (laurel forests) of the north-exposed valleys of the island where many nectar-rich plants like thistles and knapweed and diverse types of crucifers – the preferred host plants of the larval stage – grow.

Description: The Madeiran large white (Pieris wollastoni) was considered for many years as a subspecies of the fairly common Large white (Pieris brassicae) – the cabbage butterfly, but it is now regarded as a good species of its own. It was first described in 1882 and – as its name suggests – it had considerable size: 67 -72 mm wide white wings with dark tips and spots on the forewings (females were colored more yellowish, with more spots than the males). The caterpillars were green with black lumps and yellow stripes on the upper part of the body. They used to produce several generations a year from March until late October.

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First description of the Madeiran large white
by Butler in 1882 from the Annals and Magazine of Natural History

The Madeiran large white is one of the species featured on a stamp collection issued in 1997 about the butterflies of the island.

Madeiran-Large-White-Pieris-brassicae-wollastoni

Cause of extinction: Continuing decline in the area, extent and quality of the natural habitat and possibly a parasitoid wasp or an outbreak of virus infection caused by introducing the small white (Pieris rapae) to Madeira in the 1970s were the most important factors leading eventually to the extinction of the subspecies.

My special thanks to Mr. Antonio Aguiar for his expert help.

The Madeiran large white butterfly poster at the top of this post is available in my store on Redbubble, with design variations more suitable for apparel and other products. My whole profit goes to the Sea Shepherd to support their fight to protect our oceans and marine wildlife.