The Island Megafauna: Madagascar and New Zealand
Wildlife of Madagascar
At roughly the size of California, Madagascar is the fourth largest island in the world. Really, it’s big enough to think of as a mini-continent rather than an island. It formed some 88 million years ago after the vast super-continent Gondwanaland was torn apart by tectonic forces. The island we now call Madagascar was just one of its tiny fragments.
Cast adrift on this gigantic Ark was a collection of prehistoric animals that began to evolve in unique ways, spawning such weird descendants that some would later become the foundations of Polynesian myths and legends. New forms of animals quickly evolved, as the island proved to be a safe haven for any castaway. Today the island lies just 250 miles from the savannas of Africa, and yet is totally devoid of cats, monkeys, gazelles or zebras. Instead, other animals evolved to fill the same ecological roles occupied by more familiar animals elsewhere.
Through its long isolation, Madagascar is a land of outstanding endemism, with many unusual species found nowhere else on the planet, ranging from geckos that can imitate lichen to the agile and charismatic lemurs. More than 75 per cent of its species are unique to the island. However, prior to 2000 years ago, the island was even weirder, home to some of the most bizarre animals the human species has ever encountered.
When the first humans did arrive, they found gigantic birds tending nests containing an egg the size of a basketball. They must have wandered through the weird forests of spiny trees and orchids, coming across oddities such as primates the size of bullocks, weird looking insectivores and a predator that seemed to be a cross between a puma and an otter. It was probably the closest humans have ever come to walking through the pages of some grand fairy tale, full of weird and seemingly imaginary monsters.
Where is Madagascar?
Of all the animals that currently live on Madagascar, the best known to the wider world are a unique and diverse group of primates called lemurs. They are endemic to the island, but once far back in prehistory they were found throughout the world, but gradually became extinct through competition with new kinds of primates. They probably colonised Madagascar after its separation from the rest of the world by hitching a ride on a raft of floating vegetation.
Prior to human arrival, lemurs ranged in size from creatures little bigger than a mouse to monstrous giants the size of a gorilla. The 15 species of giant lemur were not simply scaled up versions of their cousins; instead they looked, behaved and moved in weird and unique ways. Some for example were terrestrial and walked on all fours like Archaeolemur and Hadropithecus. Others lived a more upside down kind of life, similar to the tree sloths of South America, hanging from branches. There were even some that climbed tree trunks vertically in the same ponderous way Koalas do, they all possessed long, dog like snouts, and one species Megaladapis may have even had a short trunk like some sort of primitive elephant.
The largest of the lemurs was Archaeoindris fontoyonti, which tipped the scales at a scarcely believable 400Ib making it the size and weight of a silverback mountain gorilla. This animal couldn’t have possibly have spent a lot of time in the trees once it reached full size, so it must have been almost exclusively a terrestrial animal, browsing on low level plants, much as the extinct ground sloths of the Americas once did.
A Bizarre Mixture of Animals
The largest native predator alive on Madagascar today is the unusual looking fossa. Measuring in at 28 inches in length, it looks like a rather jumbled up kind of animal, with the build of a cat, a dog like snout and teeth like a leopard’s. It also has whiskers reminiscent of an otter, and even more bizarrely possess webbed feet and retractable claws.
But the first human colonists encountered a much larger animal, prowling the dense forests- the giant fossa (Cryptoprocta spelea). It was built rather like a short legged puma; it was far larger and presumably more powerful than its living relative. The modern fossa helps to provide us with clues as to how its giant cousin lived. The modern fossa cruises the forest at night picking off sleeping animals. They are incredibly agile climbers, able to slip up and down trees with ease and also leap between branches like a squirrel. Once they spot prey, they attack with frightening speed. The modern fossa does routinely prey on modern lemurs, so it seems likely that the giant fossa who would have preyed upon the giant lemurs. Indeed, archaeological evidence seems to vindicate this reasoning, as the remains of both giant fossa’s and giant lemurs have been found in the same deposits.
Fossa’s were once classified as felines, but Madagascar never had any native cats. Amazingly, it turns out they actually belong to the mongoose family, it’s just that on Madagascar they evolved to fill a similar ecological niche to cats, both in behaviour and anatomy.
David Attenborough and the Giant Egg
The Elephant Bird
Lemurs and fossa’s were not the only Madagascan animals that evolved into giants. The island was also home to the elephant bird- a distant relative of the emu that was nearly twice as tall as a man and possibly the largest bird ever to walk the Earth. It stood ten feet tall and weighed half a ton. It had enormous, chunky legs, and strangely for birds, three toed feet that made its legs resemble that of a dinosaur.
The Malagasy called the elephant bird ‘Vorompatra’ which means ‘marsh bird’. Recent remains show that it lived in thinly forested marshes and wooded savannas. It was exclusively herbivorous, browsing on low vegetation, or using its long neck to reach high branches, just like giraffes. During the breeding season, it is thought to have migrated from the marshes to coastal sand dunes, where the remains of their huge basketball sized eggs can still be found today.
When the Polynesians first arrived, there were two forms of elephant bird- Aepyornis and Mullerornis, with the latter less than half the size of the former. Both belonged to an ancient order of birds called ratites that originally evolved before the breakup of Gondwanaland. Similar to living ratites such as ostriches, the elephant bird was completely flightless and possessed tiny wings that were completely useless for anything apart for display. However, unlike ostriches which need to be fast and aggressive enough to hold their own against the mammalian predators of Africa, the elephant birds were stocky and slow creatures, due to the fact they were probably free of predators; although the giant fossa may have occasionally preyed upon weak or old individuals.
The Largest Bird of All Time and its Eggs
When Humans First Discovered New Zealand
According to Maori folklore, Kupe, one of the great Polynesian navigators and heroes left his homeland Hawaiki (possibly the modern Cook Islands) and sailed southwards in search of new lands. While European history was being forged by the Crusaders and Genghis Khan, Kupe discovered the land that would one day be called New Zealand. Kupe’s wife christened the land Aotearoa, the ‘land of the long white cloud’. It was the last habitable landmass to be discovered by humans.
This particular discovery was the closest any human has come to setting foot on another planet, for the Polynesians were not just the first humans, but the first land mammals to set foot on the island. It was as if humanity had strolled into some sort of avian fantasy world, this was the land of the birds, a kingdom overseen by giants, including the tallest bird of all time and also the deadliest flying bird of all time.
Unlike Madagascar, New Zealand had never been colonised by land mammals, its extreme isolation meant that only flying animals could cross the violent southerly oceans that shielded the island from the outside world. But similar to Madagascar, New Zealand was more of a mini-continent than a true island, for it was another fragment of the ancient super-continent Gondwanaland. To the Polynesians it must have seemed vast, for New Zealand was larger than the million Pacific islands put together. Perhaps they thought that Kupe had gone and found the mythical land of unending plenty that they had all dreamt about.
Where is New Zealand?
The Birds of New Zealand
Land of the Birds
During New Zealand’s 80 million years of isolation, its birds had evolved to fill ecological niches normally filled by mammals. Birds played the roles of big cats in the form of the terrifying giant eagle, sometimes known as the Haast eagle that preyed upon New Zealand’s equivalent of the forest elephant, the moas. There were even avian equivalents of mice in the form of flightless wrens that scampered across the forest floor, occasionally falling prey to the largest of New Zealand’s frogs.
In all thirty species evolved flightlessness, while others like geese, coots, ravens and rails grew to gigantic proportions becoming fearless and slow moving, since they didn’t have to worry about ground dwelling predators. It truly must have been a startling and surreal experience for the earliest human settlers to have met so many animals that were curious rather than frightened. The Polynesians though quickly found out that it wasn’t the ground dwelling animals that commanded fear, instead it was New Zealand’s largest bird of prey that haunted the nightmares of the Maori. The giant eagle was the island’s top predator, capable of killing creatures more than 20 times heavier than itself. I have already dedicated an entire hub to the giant eagle, so I won’t go into great detail about it. But it is worth noting that the Maori etched pictures of the eagle in caves and carved its bones into tools. Some Maori legends actually refer to a mythical eagle that preyed on people. The giant eagle may have been attracted to the Maori because of their love of feathered cloaks and also the fact that they walked on two legs just like the moa.
The fauna also included strange reptiles, primitive frogs that did not have a tadpole phase and giant carnivorous snails that ate earthworms which grew up to a foot long. Many were long lost relics from the ancient continent of Gondwanaland. There were also strange oddities among the flora, which was particularly abundant. Before human colonisation more than 80 per cent of the land was covered in primeval forests containing weird plants that would have been more recognisble to a dinosaur than a human.
The Biggest and Tallest of the Moa- Dinornis
How the Moas Measure up to Man
The Foot of a Dinosaur
The best known of New Zealand’s weird birds were the flightless giants called moa. Like the elephant bird and the ostrich they were ratites, making them very ancient indeed. When the Polynesians first arrived, they were greeted by 11 species of moa, ranging from the turkey sized Pachyornis to the towering Dinornis, which stood more than 12 feet tall when fully erect, more than twice the average human height. All of the moa species were flightless and were the only birds ever known to have lost their wings completely.
They were herbivores, browsing on shrubs and trees in New Zealand’s vast forests; they were particularly common in the drier podocarp forests on the eastern side of the South Island. Today, many of New Zealand’s native plants have a fine lattice of tiny branches that evolved to protect the leaves from the hungry, lumbering moa.
Each particular species of moa had a distinct build and beak shape that were suited to a particular lifestyle in the forest. Euryapteryx for example ate berries and succulent leaves, while Pachyornis fed on tough flax. Dinornis preferred the wide range of twiggy plants, often found on the margins of the forest. Scientists know what these birds ate through studying the preserved remains of their gizzards. Indeed, the moas were alive so recently that often their feathers, skin and even DNA have survived, raising the intriguing but equally disturbing possibility that a living bird may one day be recreated.
It’s likely they lived alone or in small groups, occupying restricted home territories that were probably fiercely guarded. Due to the fact they were scattered widely through the forest, communication between individuals would have been crucial. It’s likely that they were very vocal, and indeed the shape of the neck and throat suggests that the forests were filled with the sound of its booming, low frequency call.
The moa proved to be very useful to the Polynesians who fashioned cloaks from their skin, carved ornaments and tools from their tough bones, and ate their flesh and eggs. They even used their eggs as water carriers. The Maoris’ regard of the moa is also revealed by the actual name ‘moa’ which is also the Maori word for chicken.
Two Ancient Enemies
Weird and Wonderful
While much of New Zealand’s weird and wonderful fauna has now sadly vanished, some very peculiar animals still hang on today. Among them are the tuatara, a lizard like reptile now restricted to a few rat free islands and the giant weta a huge cricket the size of a mouse that is among the heaviest insects in the world.
Tuatara’s frequently hunt wetas during the dark of the night, re-enacting a primordial battle that may have been witnessed by the dinosaurs. The tuatara is an ancient reptile that has changed very little in over 200 million years, and is the last surviving member of an ancient order of reptiles that flourished in the age of the dinosaurs. It’s one of the weirdest creatures on the planet, with a light sensitive third eye on the top of its head. It hunts during the cool of the night and spends daylight hours asleep sneakily sharing the burrows of sea birds.
The wetas are known to the Maori as ‘demons of the night’ and are also relics of Gondwanaland’s ancient fauna. These huge, wingless insects can grow bigger than mice and fill a similar ecological niche. The giant weta is the largest species, regularly reaching 2-3 ounces in weight.
Among the weirdest of the surviving birds is the kiwi, a small, flightless and nocturnal relative of the moa. They behave like hedgehogs, probing for insects, worms and larvae. Their nostrils are on the end of an unusually long and flexible beak, which they use to sniff out prey hidden in the leaf litter. They even sniff out prey underwater. Kiwis have the rather unfortunate honour of laying the largest eggs in relation to their body size; almost a third of a kiwi’s body can be taken up by a single egg.
The Kiwi and its Egg
The Short-Tailed Bat
The Bat That Runs
Before the arrival of the Maori, New Zealand was home to just four native species of mammal, all bats. Sadly one of the four, the greater short-tailed bat recently became extinct. The short-tailed bats were unusual as they had evolved the ability to scramble along the ground in a world free of other small land mammals. It possessed pouches on the sides of its body that enabled it to tuck away its folded wings, scurry down burrows and dig through leaf litter like a shrew or rat. It drank nectar from flowers, and was at least partially carnivorous, probably eating carrion and nestlings. Of the two surviving species, the lesser short-tailed bat has a forest floor lifestyle similar to its extinct cousin, while the long tailed bat lives a more typical bat lifestyle.
The Maori called bats, pekapeka, and associated them with death and destruction, although they weren’t averse to eating them on occasion. They were caught by smoking out their tree hollow roosts until they became docile.
That concludes my series of hubs on ‘The Island Megafauna’. Next I will explore the maginicent megafauna that once roamed widely across Europe...