Tag Archives: endemic species

Madagascar wildlife poster series

My new wildlife conservation awareness poster series is out featuring the amazing wildlife of Madagascar, a unique biodiversity hotspot with a range of endemic species severely endangered by the deforestation of the island.

wildlife-of-Madagascar

wildlife-of-Madagascar

This series was created in collaboration with Chances for Nature, a Göttingen (Germany) based non-profit organization working for the conservation of natural habitats and biodiversity. They have several ongoing projects around the world (you can read about them in detail on the CFN webpage); one of the locations is Madagascar. Among other things, they established an environmental education camp in the Kirindy Reserve in the western part of the island where they bring local children to the forest to observe the animals as closely as researchers do – many of the species featured on the posters occur in this relatively small area.

For now, the new series is available in my RedBubble store on posters, art prints, spiral notebooks and stickers. Similarly to the two original series I plan to create design versions more suitable for apparel and to write a blogpost about each of the species later.

The Goodfellow’s tree kangaroo – back to the canopy

Goodfellows-tree-kangaroo-Dendrolagus-goodfellowi

Goodfellows-tree-kangaroo-Dendrolagus-goodfellowi

Goodfellow’s tree kangaroo

Tree kangaroo might sound like an oxymoron to someone not familiar with the wildlife of New Guinea, but these arboreal macropods really do exist and inhabit the tropical rainforests of the island and the far northeastern territory of Queensland, Australia. In fact, the evolutionary history of tree kangaroos is a beautiful example of how life will always adapt to a new habitat to fully exploit its environmental carrying capacity.

Looking at the map one would naturally assume that the wildlife of New Guinea is similar or closely related to the fauna and flora of the other islands of the Indonesian archipelago. This supposition proves to be rather untrue: though New Guinea’s flora is a mixture of tropical rainforest species with Asian origin and typically Australasian plants, the second largest island of the Earth is inhabited overwhelmingly – and surprisingly – by animals of Australian origin.

endangered-tree-kangaroos-New-Guinea-Goodfellow's-tree-kangaroo-Dendrolagus-godfellowi

endangered-tree-kangaroos-New-Guinea-Goodfellow’s-tree-kangaroo-Dendrolagus-godfellowi

New Guinea’s endangered Goodfellow’s tree kangaroo
©Copyright Zweer de Bruin / CC BY-NC-ND 2.0 

The explanation lies in the geological history of the region: unlike the rest of the archipelago, New Guinea with the surrounding smaller islands is part of the Australian continental plate called Sahul and not the Sunda Shelf (extension of the Southeast Asian continental shelf). Sahul had separated from Antarctica and South America by the beginning of the Miocene; and kept slowly drifting northwards, colliding with the Sunda Shelf about 15 million years ago.
For long periods from the Miocene until the Holocene, today’s Australian mainland and New Guinea were linked by a land bridge during the repeated episodes of glacial advance when sea levels fell more than 100 meters and Sahul was exposed as dry land. Similarly, from time to time the Sunda Shelf used to be a continuous land mass connecting southeastern Asia and the Indonesian islands – Borneo, Sumatra, Java, Bali. In these periods the migration and distribution of species on the mainland and the respective future islands was unrestricted, but a barrier of a wide deep-water sea-channel along/above the colliding edges of the two continental shelves kept most species from crossing, and thus Asian and Australian wildlife – especially fauna – mostly separated.
However, many plant species have managed to spread through the channel; and as Sahul kept slowly drifting north to the tropical zone and the climate has gradually changed, the lush vegetation of the Asian tropical forests started to invade and replace the original flora on the northern territories of the shelf, developing into an entirely new habitat. This vegetation was quite different from the native flora, providing superior quality food in comparison with the plants of that age that were adapted to the more arid climate of the Australian landmass.
Only few animals – mainly bats and birds – have been able to cross the stretches of open water between the shelves; and the absence of leaf monkeys or any leaf-eating mammals occupying the canopy of the average Asian tropical forest left this niche of the new forests empty, presenting an evolutionary opportunity.

Goodfellow's-tree-kangaroo-Dendrolagus-godfellowi-montane-tropical-forest-habitat-loss-endangered

Goodfellow’s-tree-kangaroo-Dendrolagus-godfellowi-montane-tropical-forest-habitat-loss-endangered


Tree kangaroos inhabit montane and lowland tropical forests of New Guinea and northeastern Australia
©Copyright Stu Rapley / CC BY-NC-ND 2.0 

Around that time, rock-wallabies were abundant in northern Australia. Rock-wallabies are terrestrial kangaroos, but some of their species have a propensity to climb trees to feed on the flowers, fruits and leaves. Molecular evidence – genetic studies show that the Proserpine rock-wallaby is the closest living relative of tree kangaroos – strongly suggests a rock-wallaby ancestor around 5-7 million years ago that moved in into the new habitat and has slowly adapted to the arboreal lifestyle, evolving over time into a dozen of new species today known as tree kangaroos.
At the end of the last glacial period about 12 000 years ago the rising sea level separated New Guinea from the Australian mainland: most species of tree-kangaroos live now in the tropical forests of the islands, only two species are native in Queensland. Most tree-kangaroos are endangered, with decreasing populations threatened by hunting for food and by habitat loss: one of the endangered species is the Goodfellow’s tree kangaroo, also known as ornate tree kangaroo.

Range: The Goodfellow’s tree kangaroo is endemic to the island of New Guinea; the current range of the species covers the mid-montane regions of the Central Cordillera from the Indonesian border to Milne Bay province. Historically it used to occur in lowland areas too but now it’s locally extinct: rapid deforestation of these regions has destroyed most of its habitat.

Habitat: Goodfellow’s tree kangaroos inhabit montane and lowland tropical forests, they adapted to a canopy-dwelling lifestyle.

New-Guinea-wildlife-Goodfellow's-tree-kangaroo-Dendrolagus-godfellowi

New-Guinea-wildlife-Goodfellow’s-tree-kangaroo-Dendrolagus-godfellowi


Goodfellow’s tree kangaroos have two golden stripes on their back and every individual has a unique pattern of rings and blotches on their tail
©Copyright  C Steele / CC BY-NC 2.0 

Description: The anatomy of the Goodfellow’s tree kangaroo (Dendrolagus goodfellowi) is a great example of a living transitional form of evolution. Tree kangaroos have several features clearly showing the adaptation to arboreal lifestyle; but their general anatomy is still close to the ground-dwelling ancestor and is rather unsuited to a life in the canopy of trees. They have shorter and broader hind limbs with ankle joints that are modified from the highly specialized ankles of terrestrial hopping kangaroos to allow the foot to be rotated to grip branches; their arms are proportionally larger and stronger; they have rubbery pads on the soles of their feet and their paws and large, curved claws; their tail is lighter built and they use it well to balance while moving; and – unlike hopping kangaroos – they can move their hind limbs independently. But compared with perfectly adapted tree-dwelling animals like monkeys, possums or squirrels they are still clumsy climbers.

Goodfellow’s tree kangaroos have a body length of around 55-80 cm with a tail length of 70-85 cm. They have maybe the nicest coloration among tree kangaroos: their short, wholly fur has a soft reddish-brown shade; they have a greyish-brown face and light golden underbelly, throat and limbs. Two longitudinal golden stripes run on their back where they have a characteristic vortex of hair. Every individual has a unique pattern of brown and golden rings and blotches on their tail.

Goodfellow's-tree-kangaroo-New-Guinea-montane-tropical-forest-fauna

Goodfellow’s-tree-kangaroo-New-Guinea-montane-tropical-forest-fauna

Goodfellow’s tree kangaroos eat large quantities of leaves
©Copyright Nathan Rupert / CC BY-NC-ND 2.0 

Goodfellow’s tree kangaroos feed mainly on leaves of the forest trees; but occasionally they consume flowers, fruits, cereals and even insects. They have a sacculated stomach with fermenting bacteria to digest the large quantities of fibrous foliage. They are active in the morning and afternoon, except near human settlements where they are mostly nocturnal.

Goodfellow’s tree kangaroos are solitary and territorial animals. Being marsupials, females have a well-developed pouch opening forward. They have one young per birth after a 21-38 days gestation period, and the joey grows for almost a year in the pouch before first leaving.

Goodfellow's-tree-kangaroo-conservation-breeding-program-zoo

Goodfellow’s-tree-kangaroo-conservation-breeding-program-zoo


Endangered Goodfellow’s tree kangaroos in the Melbourne Zoo
©Copyright Tim Williams / CC BY 2.0 

Threats: Except humans there are virtually no predators or competitors for Goodfellow’s tree kangaroos in their habitat; the species – as all tree kangaroo species – is primarily threatened by uncontrolled hunting for meat and extensive habitat destruction. The lowland tropical forests of the island had been almost completely eliminated and replaced by plantations – coffee, rice, palm oil and wheat – and farm gardens of locals; and logging continues in the montane areas for timber, mining and more agricultural land.

 

The Goodfellow’s tree kangaroo 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 globe-horned chameleon – individualist of the rain forest

globe-horned-chameleon-Calumma-globifer-Madagascar-endangered

globe-horned-chameleon-Calumma-globifer-Madagascar-endangered

The globe-horned chameleon is one of the chameleon species endemic to Madagascar

Chameleons are fascinating creatures for many reasons. They have a couple of morphological features and unusual abilities that make their appearance truly unique and somewhat bizarre: their hands and feet are fixed in a grasping position to help them cling to branches – arboreal species also have a prehensile tale for that, accurately curled up like a spiral when resting; they have extra-long, extensile tongues for catching insects at a distance sometimes bigger than their own length; they have unique, bulging eyes that can turn and focus independently giving them a full 360 degree view –  they can see in both visible and ultraviolet light; and they are most recognized for their ability to change their skin coloration and pattern – contrary to popular belief, the main reason for that is not camouflage but to convey their emotions and to communicate with mates.

Chameleons come in many sizes from 15 mm up to 75 cm; many of them have variously sized and shaped casques, horns, crests or other protrusions or appendages on their heads, and spikes along their spine from neck to tail.  They have a characteristic swaying gait rocking slowly back and forth between each step taken. Unlike other animals, they continue to grow throughout their lives, shedding their old skin in pieces.

endangered-globe-horned-chameleon

endangered-globe-horned-chameleon

Endangered globe-horned chameleon
©Copyright Linda de Volder

These extraordinary, colorful lizards live in warm habitats – ranging from humid forests to deserts – of mainland Africa, Madagascar, southern Europe, some regions of the Arabic and Indian peninsulas and the island of Sri Lanka. From the more than 200 known chameleon species (according to the IUCN listing) 85 can be found on Madagascar. Many of them are endemic to the island – Madagascar has an 88 million years long history of relative isolation, 90 percent of its wildlife can be found nowhere else on the planet. This unique wildlife and ecosystem is severely threatened by different activities of the island’s growing human population – the globe-horned chameleon is one of Madagascar’s 28 chameleon species assessed as endangered or critically endangered.

Range: The globe-horned chameleon is endemic to Madagascar, with a current distribution range restricted to a relatively small area of around 675 km² (based on the size of the residual forest patches around the locations of confirmed sightings) in the central highlands between elevations of 1200-1500 meters.

Habitat: The residual humid montane rainforest of the central highlands. Globe-horned chameleons live in the mid-upper stories of the forest; they prefer areas with old, big trees, mossy branches and twined lianas, often alongside streams.

Calumma globifer, female

Female globe-horned chameleon
©Copyright Matthias Markolf All rights reserved

Description: The species was first described by German zoologist Albert Günther in 1879. The globe-horned chameleon belongs to the larger chameleon species: females are a bit smaller than males, with a body length of around 15/17 cm and a tail of 30/39 cm, respectively.

Globe-horned chameleons have a backwards directed flat casque on their head – the species is also known as flat-casqued chameleon -, and males have two small globular nose appendages. They don’t have spikes on their back and the scalation of their skin is heterogeneous. Their color range – as by many chameleon species – covers different shades of brown, yellow, green and gray; on their side from head to tail they have a wider horizontal stripe with variable colors and usually three or more diagonal stripes. Males have a whitish-yellowish pattern on their throats.

Calumma globifer

Close-up of a male globe-horned chameleon – also known as flat casqued chameleon – showing both eponymous features
©Copyright Matthias Markolf All rights reserved

Globe-horned chameleons – as all chameleon species – are insectivores, hunting by projecting their tongue to capture the prey. They are diurnal, live solitarily and are often aggressive towards other members of their own species, showing their emotions by rapid color change. There’s no information about the breeding and mating habits of the species, it’s only known that females lay around two dozen eggs in a clutch.

Threats:  As most chameleon species of Madagascar the globe-horned chameleon is mainly threatened by the rapid loss and degradation of the island’s original forests. The continuous deforestation of Madagascar started with the arrival of humans around 2350 years ago and accelerated rapidly in the second half of the 20th century – around 40 percent of the forest areas were lost in that period, making altogether 90 percent of the original forests gone. Forest loss is largely attributed to the traditional slash-and-burn agricultural method imported to the island by the earliest settlers, (partly illegal) logging for charcoal and construction materials, and recently the increasing demand in land suitable for cattle grazing and coffee plantations. The increased exploitation of natural resources as a repercussion of the political events of the last decade had dire consequences for the island’s wildlife and forest conservation: several species are threatened with extinction.

Ambohitantely-forest-reserve-Madagascar-chameleon-habitat

Ambohitantely-forest-reserve-Madagascar-chameleon-habitat

The Ambohitantely Forest Reserve located 140 km northwest of Antananarivo
©Copyright Ambohitantely.blogspot.com

Chameleons are popular pets all around the world and the globe-horned chameleon is also threatened by illegal trade – the legal export of all Calumma species is currently suspended on Madagascar.

 

The globe-horned chameleon 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

pinta-island-giant-tortoise-Chelonoidis-abingdonii-extinct-Lonesome-George

pinta-island-giant-tortoise-Chelonoidis-abingdonii-extinct-Lonesome-George

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.

critically-endangered-Galápagos-giant-tortoises

critically-endangered-Galápagos-giant-tortoises

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 16th 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 20th 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.

Lonesome-George-last-giant-pinta-tortoise

Lonesome-George-last-giant-pinta-tortoise

Lonesome George, the last known Pinta Island tortoise
©Copyright 3rdfloorCC 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.

arid-zone-opuntia-forest-Galápagos-Santa-Cruz-Island

arid-zone-opuntia-forest-Galápagos-Santa-Cruz-Island

humid-highland-zone-Scalesia-forest-Galápagos-Santa-Cruz-Island

humid-highland-zone-Scalesia-forest-Galápagos-Santa-Cruz-Island

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 KrentzelCC BY 2.0  and Andy KraemerCC 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.

domed-shell-giant-Galápagos-tortoise-carapace-form

domed-shell-giant-Galápagos-tortoise-carapace-form

Galápagos tortoise with domed shell, the ancient carapace form characteristic to species from more humid islands
©Copyright Aki SasakiCC 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.

saddleback-shell-giant-tortoise-Galápagos-carapace-form

saddleback-shell-giant-tortoise-Galápagos-carapace-form

Galápagos tortoise with saddleback shell, characteristic to populations from more arid islands like Pinta Island
©Copyright Andy KraemerCC 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.

Galápagos-tortoises-resting-cooling-muddy-pool

Galápagos-tortoises-resting-cooling-muddy-pool

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 16th 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.

endangered-Galápagos-giant-tortoise-migrating

endangered-Galápagos-giant-tortoise-migrating

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

extinct-little-mariana-fruit-bat-Pteropus-tokudae-Guam-flying-fox

extinct-little-mariana-fruit-bat-Pteropus-tokudae-Guam-flying-fox

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.

fruit bats megabat flying fox on the sky

fruit bats megabat flying fox on the sky

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.

Mariana fruit bat endangered bats flying fox

Mariana fruit bat endangered bats flying fox


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.

brown tree snake Guam birds flying fox extinction invasive predator species

brown tree snake Guam birds flying fox extinction invasive predator species

The brown tree snake might have been a factor in the extirpation of the little Mariana fruit bat
©Copyright Pavel KirillovCC 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 Bali tiger – hunted to extinction

bali-tiger-Panthera-tigris-sondaica-extinct

bali-tiger-Panthera-tigris-sondaica-extinct

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 20th 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

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

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 jacksonville zoo tiger conservation program


Sumatran tiger cub in the Jacksonville Zoo
©Copyright ValerieCC 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

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 20th 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

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 Siamese bala shark – a victim of aquarium trade

burnt-tailed-barb-siamese-bala-sharks

burnt-tailed-barb-siamese-bala-sharks

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

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

Bala sharks are not true sharks
©Copyright Gogo78 CC BY-SA 3.0 (via Wikimedia Commons)

Balantiocheilos-melanopterus-aquarium

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

Madeiran large white butterfly

The Madeiran large white butterfly is one of the many species that were last seen in the 20th 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

Female Madeiran large white

Female Madeiran large white
©Copyright Antonio Aguiar via Arkive

male Madeiran large white

male Madeiran large white

Male Madeiran large white
©Copyright Antonio Aguiar via Arkive

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.

description-Madeiran-large-white-butterfly-Butler-1882

description-Madeiran-large-white-butterfly-Butler-1882

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

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. 

Dodo – the emblem of extinction

dodo the emblem of extinction

dodo the emblem of extinction


Dodo – the emblem of extinction

The dodo is probably the most famous in the long line of extinct animals of the last few hundreds of years. Being the species that made humankind realize the fact that an animal can actually and permanently disappear from existence because of the impacts of human civilization made the dodo a generally known icon of extinction; and appearing as a character in Lewis Carroll’s novel Alice’s Adventures in Wonderland (1865) and in the popular animated movie franchise Ice Age established its prominent position in modern pop culture.

Date of extinction: The last widely accepted sighting of a dodo dates to 1662.

Range: The dodo was endemic to Mauritius, a small island in the Indian Ocean about 2000 km off the southeast coast of the African continent, east of Madagascar.

Habitat: Natural rainforests at the coastal area of the volcanic island with tropical, humid climate.

Cause of extinction: With the arrival (1598) and settling of the Dutch sailors, the rainforests of the island were gradually destroyed and replaced by plantations of imported crops (sugar cane, rice, tobacco, citrus trees etc.) to cater to the needs of the drastically increasing human population. With its natural habitat disappearing rapidly, the flightless, tame bird was hunted to extinction by the predators – dogs, cats, rats, pigs and macaques – introduced to the island by the settlers. According to prevalent opinion the settlers themselves also consumed the dodo’s meet, though recent archaeological investigations have found scant evidence of human predation.

George Edward's Dodo painting

George Edward’s Dodo painting


One of the most copied but incorrect depictions of the dodo:
Roelant Savory’s painting of ornithologist George Edwards’ stuffed specimen, around 1620

Description: Recent scientific examinations also show that the common portrayal of the dodo in literature and pop culture as the archetype of the plump, gluttony, dumb(ish) bird is largely incorrect. Descriptions about the bird from the 17th century are contradictory regarding the details (colors, plumage, tail, beak etc.) of its look, with only a few – rather poor quality – drawings made of wild individuals. The numerous depictions created in the later centuries either copy the few originals made of living dodos brought to Europe and overfed in captivity or were made of badly stuffed specimens. These stuffed specimens were all damaged or lost during the centuries until only a dried head and a foot remained with soft tissue (in the Oxford University Museum of Natural History); along with a few dozen of incomplete and composite skeletons und subfossils mainly found in the excavations of the Mare aux Songes swamp in Southern Mauritius around 1865 and 2005.

Dodo skeleton Durrell Wildlife Park

Dodo skeleton Durrell Wildlife Park


A composite dodo skeleton from the Durrell Wildlife Park,
© Josh More – www.starmind.org 

Based on the scientific and forensic examinations of these remains and the few legit depictions of living specimens in the 17th century in Europe and India, dodos were neither particularly fat nor dumb – their build and brain size agrees with the parameters of bird species living in similar habitats and conditions. The dodo was about 1 meter tall and weighed about 15 kg; his closest relatives are Asian pigeons but the dodo adapted perfectly to a life on an isolated island with no predators and evolved to a flightless bird with short wings, a bulky body, stubby, strong legs and strong, crooked beak.

accurate dodo depiction Mughal Ustad Mansur India

accurate dodo depiction Mughal Ustad Mansur India


One of the few more accurate dodo depictions from India
by Ustad Mansur c. 1625

However, as the skeletons don’t really provide any clue about the outer details, fact is that after 350 years of its disappearance we have only speculations about how exactly the dodo could look like…

 

The dodo 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.