21 September 2011 ~ 0 Comments

Madagascar: Life At An Evolutionary Tangent

Brown Mouse Lemur, Nosy Mangabe, Madagascar
Creative Commons License photo credit: Frank.Vassen

Cast adrift in the Indian Ocean, Madagascar has been separated from other landmasses for longer than any other island on earth. For tens of millions of years evolution has played here in virtual isolation, heading off at a different tangent to the rest of the world.

This lengthy geographical separation is key to the otherworldliness of the wildlife you’ll see in Madagascar today. Between 80 and 90 percent of the island’s plants and terrestrial animals exist nowhere else. There are no giraffes or elephants, nor lions or tigers. Indeed Madagascar has no native large mammals or even representatives of the cat or dog families. Numerous other globally widespread animal groups are also conspicuously lacking and their very absence has been a significant factor in allowing so many new species to emerge and thrive on this remarkable island.

A map of Madagascar's Protected Areas

Image via Wikipedia

Primates are a case in point: Madagascar is the exclusive home of around a quarter of all primate species on our planet, yet there are no monkeys or great apes. Aside from humans – who are not thought to have settled the island until a mere 2,000 years ago – all the primate inhabitants belong to a group known as lemurs. And they exist in glorious variety: more than 100 different species and subspecies – big and small, nocturnal and diurnal, social and solitary, adorably cute and downright freaky.

A single common ancestor gave rise to the potpourri of lemurs you’ll spot in Madagascar’s forests today. Sometime between 40 and 60 million years ago, it is thought an ancestral lemur – a single pregnant female or perhaps a couple huddled together – was swept out to sea in a violent storm on the African coast. The creature was washed up on the shores of Madagascar, having survived the ocean crossing against all the odds, probably by clinging to a raft of floating vegetation. It would have crawled up the beach sodden, exhausted and entirely unaware of the pioneering significance of its arrival. It was to prove a fortuitous journey for its kind indeed, because not long afterwards they were wiped out on mainland Africa in the face of growing competition from their newly evolved and more advanced monkey cousins.

Madagascar, on the other hand, would have been a welcoming place for the new arrivals. With few potential predators and an inviting array of different habitats and ecological niches to exploit, the early lemurs rapidly spread out and diversified into numerous different forms in a process biologists call adaptive radiation. Each new species became specialised in making the most of a different environment and finding nourishment from a different range of foods.

As a group the lemurs flourished. Some developed powerful back legs to propel themselves from tree to tree, leaping through the rainforest canopy; others adapted to foraging on the ground. Some evolved highly sensitive sight and hearing enabling them to be active at night, while others sought safety in numbers and began to live in social groups. One species adopted a diet consisting almost exclusively of bamboo shoots, ingesting a dose of cyanide each day that would kill a human. Another opted to live semi-aquatically, in the reed beds of Madagascar’s largest lake.

Arguably the most specialised and certainly the most bizarre, of the lemurs is the aye-aye. It truly is unique, so much so that the first European scientists to receive a specimen from early explorers scratched their heads in bemusement and eventually classified it as a type of squirrel. Only after much debate and several reclassifications was it finally agreed that the aye-aye is in fact a kind of lemur. It is the sole species not only of its genus, but also in its entire family, meaning there is nothing else in existence remotely like it.

Aye-aye (Daubentonia madagascariensis)

Image via Wikipedia

Aye-ayes are nocturnal cat-sized creatures with shaggy black coats, spending much of their lives high up in the canopy of both deciduous forests and rainforests. They have continually growing incisor teeth, just like rodents (part of the reason they were first thought to be squirrels), huge satellite-dish ears that can be swivelled to locate the faintest sound with pinpoint accuracy and a long, skeletally thin middle finger. These features collectively constitute a specialised toolkit for the aye-aye’s favourite activity: grub hunting.

Tapping rapidly on the bark of a tree, an aye-aye listens for the echo that indicates a hollow chamber within. So sensitive are its ears, they can detect the movement of grubs beneath the bark. Once such a snack has been located, the sharp teeth are used to gnaw a small hole into which the slim bony finger can be inserted to winkle the grubs out into the aye-aye’s waiting mouth.

In this way, the species has evolved to fill the ecological niche typically occupied throughout the rest of the world by woodpeckers – a group of birds which has never found its way to Madagascar. Little wonder that those early taxonomists had difficulty placing such an enigmatic creature in the system of biological classification.

Madagascar’s numerous protected areas allow plenty of opportunity for you to watch lemurs at work and play, such as the spectacular canyons of Isalo National Park in the central south. Isalo is famed for its dramatic scenery of majestic sandstone outcrops. The area is excellent for hiking and popular with botanists for its numerous succulent plants, several of which are endemic to the local area. It’s also a wonderful place to watch the iconic ring-tailed lemurs, handsome teddy-bearfaced Verreaux’s sifakas and ever-curious red-fronted brown lemurs. Three further species are active in the reserve by night.

Even greater numbers of lemur species can be seen in Madagascar’s lush rainforest reserves in the east and north of the country. Andasibe-Mantadia National Park is the most easily accessible, yet also among the most rewarding. The highlight here is the indri – the largest of all lemurs. These endangered animals live in small family groups and resemble oversized, enchantingly fluffy, black-and-white koalas. Every morning their eerie wailing carries for kilometres across the forest as the groups call to one another. Being woken by this hauntingly beautiful song is a memory that stays with you forever. And seeing the indri is a truly unique Madagascar experience, for no zoo has ever succeeded in keeping this species alive in captivity.

Andasibe-Mantadia is home to no fewer than 11 other types of lemur, as well as countless birds, reptiles and frogs. Among the reptiles found here is the mighty Parson’s chameleon – the largest chameleon in the world, measuring up to 70cm from nose to tail tip (although it might need the help of your guide to spot it camouflaged on a branch).

Just like the lemurs, dozens of chameleon species have evolved and adapted to nearly every habitat in Madagascar: almost half of the world’s species are native to this one island. They are fittingly outlandish characters. We all know that chameleons possess the extraordinary ability to turn different colours – some species more strikingly than others – but, contrary to traditional wisdom, their colour change normally reflects their mood rather than their background. Some, on meeting a potential mate, or when faced with a rival trespassing on their territory, will puff themselves up and explode into an alarming kaleidoscopic display of polychromatic emotional expression.

A chameleon’s eyeballs are arguably as interesting. Armour-plated, with only the small pupil exposed, they swivel like gun turrets: operating independently so one looks forward, as the other watches for dangers from behind. But once a chameleon spots potential prey – a juicy cricket, perhaps – the two roving eyes are coupled for binocular vision. Focusing on the target, together the eyes give the chameleon three-dimensional vision, so distances can be judged. This is critical, for the creature to unleash its deadly weapon accurately: its tongue. The chameleon’s highly elastic tongue can typically be extended by a full body length. It is unleashed with impressive accuracy and at lightning speed: taking just three hundredths of a second to hit its prey – faster than the perception of the human eye and more importantly, faster than most insects’ reactions. The tongue’s tip is slightly sticky with mucus but actually grabs the prey by forming a suction cup. It is then swiftly reeled back, to be crunched up by strong jaws and a set of tiny sharp teeth.

Meanwhile, at little more than two percent the length of a giant Parson’s chameleon, the pygmy stump-tailed chameleon is the world’s smallest and another unique resident of Madagascar. Considerably smaller even than some of the insects with which they share their forest floor habitat, these miniature lizards are among the tiniest of all reptiles: though they can be spotted with the help of a keen-eyed guide at Montagne d’Ambre National Park in the far north of the country. Montagne d’Ambre is the oldest of the national parks, protecting an isolated area of montane rainforest with a well-maintained trail system. You’ll find a wide and wonderful array of chameleons here, as well as a huge variety of geckos and frogs. Birding is good in the park, and you’ll often spot lemurs, as well as ring-tailed mongooses. Among the luxuriant plant life on show, are countless beautiful and delicate orchids: with more than 1,000 species, Madagascar has more varieties of orchid than the whole of mainland Africa.

Now, more than ever, is the time to visit Madagascar. Despite more than 90 percent of its original forest having been lost, Madagascar is still arguably the most important of all our biodiversity hotspots. The sheer array of flora and fauna is staggering – but increasingly under threat. As the country grapples with rising levels of poverty, a rapidly growing population in need of land for crops and charcoal to cook with, illegal  logging of precious hardwoods, slash-and-burn agriculture, oil and mining projects with potentially serious environmental impacts, it is clear that massive conservation challenges lie ahead. But ecotourism provides local employment and generates much-needed revenue to help Madagascar tackle some of these issues. At the same time this reinforces the message that the country’s natural heritage is a valuable asset worth protecting. But whatever your reason for visiting, you’ll waste no time discovering that to experience Madagascar, is to experience nature in all her glory.

Madagascar Facts

Location: Madagascar lies off Africa’s south-east coast and is the fourth largest island in the world. It is in the Indian Ocean and separated from Africa by the 500-mile wide Mozambique Channel.

Population: 19.5 million

Languages: Malagasy is the national language, the other official language is French.

Time: GMT +3

Money: The Malagasy ariary (MGA) . Currently MGA3,247,440 to UK£1.

When To Go: There are only two seasons in Madagascar: wet and dry. The hot, wet season lasts from December to March (including the cyclone season in February and March). The cooler, drier season lasts from April to November.

Where To Stay: Mandrare River Camp, close to Fort Dauphin in the south of the island, is the finest luxury camping experience in Madagascar. Spot lemurs in the gallery forests, learn about the local Antandroy tribe and enjoy the excellent food.

What To Read: Madagascar: A World Out of Time by Frans Lanting. This book is primarily a portfolio of almost one hundred photographs taken in Madagascar by Frans Lanting, who has been described as “the most versatile wilderness photographer working today”. The photographs were commissioned and financed by the National Geographic Society.

What Not To Miss: Seeking out the indri indri in Andasibe National Park, Madagascar’s largest lemur. Whale watching by boat at Manafiafy Beach & Rainforest Lodge in the south-east corner of the island.

Best Meal: Malagasy curry with a fruit dessert prepared with local vanilla.

Insider Tip: Do not try to cover the whole island in a two-week holiday, it is about the size of France and the infrastructure means that flying is necessary. Pick two or three key areas and focus on them.

Cox & Kings offers luxury holidays and tailor-made holidays to Madagascar.

Enhanced by Zemanta

Continue Reading