Friday, 18 August 2017

Madagascar: 'the eighth continent'

We have just returned from a memorable, enthralling (and often challenging) 17 days in Madagascar, which has long been a distant dream of mine. Some years ago I gave up on it, largely in view of the many grim reports I was getting on the extent of environmental destruction there, but events offered me an opportunity, and I was persuaded that though the damage is very real, the reserved areas and their amazing biota warranted a visit. Both aspects of that assessment were borne out by our experience there. 
Indri Indri indri (!), largest of the living lemurs, Andasibe-Mantadia NP.
I am still pretty wrung out by it all (we've been back less than 72 hours) so this is just a brief overview of the astonishing island and its nature; there will be more detailed posts on various animal groups and individual parks in times to come.

The 'eighth continent' moniker is often cited and, while probably unsupportable, it does indicate an important truth - Madagascar is in no way part of Africa. Indeed its most recent direct contact with the rest of the world was when it split away from India 88 million years ago; it drifted more recently to its current position off the south-coast of Africa, 450km from it across the Mozambique Channel.
Location of Madagascar in the western Indian Ocean (per Mobot ).
If slid east along the latitudes to overlay eastern Australia, it would cover the area roughly
from mid Cape York Peninsula to Fraser Island; at 1600km from north to south,
it is big. At 593,000 square kilometres it is roughly the size of Spain, or twice that
of Britain and Ireland.

Madagascar map (per Maps of the World); most of the locations referred to below can be found here,
though you'll need to click on it to see detail.
Another important reason that it is not truly African is that its people are not - the original Malagasy inhabitants arrived, probably less than 1500 years ago, and from the east. Specifically they were from Borneo (attested to in the modern Malagasy language, as well as ethnically), blown across the Indian Ocean in outrigger canoes. Later on colonists certainly arrived from Africa, and blended with the Indonesians (and later other peoples) to form the modern Malagasy people.

By the end of the 15th century amalgams of people from different parts of the island began to form 'kingdoms' which struggled for supremacy, though the Merina kingdom of the central highlands, around the modern capital of Antananarivo, came to dominate. This lasted until the late 19th century, when a French invasion, followed by political skulduggery, reduced the independent nation to a French colony, which it remained despite strong resistance until eventual re-independence in 1960. Sadly this was only after an unprecedentedly brutal crushing of an uprising, wherein French troops slaughtered at least 100,000 civilians. Today Madagascar is one of the world's poorest countries, with a per capita Gross National Income of less than US$400, and a rapidly growing population of 24 million.

The extent of habitat destruction across the highlands - which represent the majority of the land area - is shocking. We drove for whole days without seeing any native vegetation; sadly for us, invasive eucalypts are a huge problem, though local people rely heavily on them for firewood, charcoal and building materials.
Central highlands (above and below), south of Antananarivo; virtually all the trees visible are eucalpyts
(of a surprising number of species) with some pines.

It's hard to know just what was lost, but it seems to have been a mix of closed evergreen forest higher up, and more open woodland lower down. Until well into human times this region supported giant lemurs (some of them larger than modern gorillas), several species of the giant elephant-birds, and giant tortoises. I can say that it is extremely dispiriting to drive for hour on hour through such devastation (and no, I'm not making value judgements, just responding to what has been lost).
Eucalypt-dominated landscapes south of Antananarivo, above and below.
(Most of the pictures were taken from the bus window.)

There are some remnants of the original highlands vegetation left in reserves on the northern and southern fringes of the highlands, but not of the central highlands. The following photos are of sub-humid forest types representative at least of the regions where they survive.

Ankarana NP, just south of Amber Mountain.

Anja Community Reserve, in the south, near Isalo NP on the map.
In the eastern lowlands are rainforests, which are better conserved. Andasibe-Mantadia (east of the capital) and Ranomafana (further south) are very important rainforest reserves.
Rainforest, Andasibe-Mantadia NP.

Rainforest, Ramanofana NP, above and below.

Forests which we would call vine or monsoon forests (formally Dry Deciduous Forests in Madagascar) once covered vast area of the west (which we did not visit) and the far north, but they too have been reduced to fragments. Nonetheless the World Wildlife Fund describes them as "one of the world's richest and most distinctive tropical dry forests". Such forests grow in regions of high seasonal rainfall followed by months of drought.
Amber Mountain NP, far north.

Dry deciduous forest, Ankarana NP in the north.
In the far south and south-west succulent woodlands grade into the very arid and remarkable spiny forests, like nothing else on earth. Octopus Plants (Alluaudia spp.), baobabs and euphorbs predominate.
Ifaty spiny forest (north of Toliara on the map).

Octopus plants and baobabs, Ifaty.
On the subject of baobabs, Madagascar is home to six of the world's nine species (there are also two in Africa, one of which was only recently described, and one in Australia). 
Fony Baobab Adansonia rubrostipa, Ifaty forest.
Madagascar is also home to some 200 species of palms - three times as many as the whole of continental Africa.
Bismarck Palms Bismarckia nobilis, far south; among the very few native plants spared in this landscape.

Remnant palms, Toliara.
These groups in Madagascar originated in Africa, but others, such as the pitcher plants, came from the opposite direction (like the people), drifting from Asia.
Nepenthes madagascarensis, Pangalenes Lakes, east coast.
It's not hard to imagine baobab or palm seeds floating, or palm fruits carried by birds, from Africa, but what about non-flying animals? Their ancestors can only have floated in on rafts of vegetation, a phenomenally unlikely event; moreover the ocean currents which made it possible ceased to flow between 15 and 20 million years ago. This means that very few animal groups have made the crossing, they have had plenty of time to diversify in isolation.

Endemism - ie living nowhere else on earth - is very high indeed. For instance all the native non-flying mammals, 99% of the frogs, 95% of reptiles, nearly 90% of flowering plants and 44% of birds are endemic to Madagascar.

The most famous of these are of course the lemurs, whose ancestors were an ancient primate which later also gave rise to bushbabies and pottos in Africa, and lorises in Asia; modern monkeys didn't appear for tens of millions more years. They arrived in Madagascar an astonishing 50 to 60 million years ago, and have diversified into five living families - a third of the world's living primate families. In addition three lemur families have become extinct since the advent of humans.

Here is a sample of lemur species.
Ankarana Sportive Lemur Lepilemur ankaranensis, Ankarana NP.

Eastern Grey Bamboo Lemur Hapalemur griseus, Pangalenes Lakes, east coast.

Red-fronted Brown Lemur Eulemur rufifrons, Isalo NP; gathering fallen figs from the forest floor.

Surely the most extraordinary of living lemurs is the Aye-aye Daubentonia madagascariensis, the only living member of the family (though a second became extinct in recent times).
Here at Pangalenes Lakes a small population is isolated on an island and has become partially habituated
under very strict control. She has used her amazing incisors to open the coconut provided; normally she uses them
to cut into wood, from which she extracts grubs with a slender adapted forefinger.
(No flashes allowed!)
And yes, there will be a post entirely devoted to lemurs in the near future.

Only three more groups of land mammals ever made the crossing; the tenrecs, a uniquely African group of no close affinities 42-45 million years ago, the Madagascan carnivores 20-26 million years ago, and the rodents at about the same time.
Lesser Hedgehog Tenrec Echinops telfairi, Ifaty Forest.
Having been extracted from its daytime refuge (not at our request!) this one sensibly declined
to unroll in our presence. There are over 30 species, which have evolved to fill a range of habitat niches,
including those of burrowing moles, climbing rodents and small otters.
Ring-tailed Vontsira Galidia elegans, Amber Mountain NP.
There are eleven species of these uniquely Madagascan carnivores, which derived from the
'cat-like' carnivores; they are most closely related to (but still very distant from) the mongooses and hyaenas.
Madagascar is also the world capital of chameleons! The 85 species, all endemic, represent 42% of the world's species, in less than 0.4% of its land area. They include the world's largest and smallest species. 
Oustalet's Chameleon Furcifer oustaleti, Anja Community Reserve.
Arguably the world's largest chameleon (disputed by Madagascar's Parson's Chameleon),
at nearly 70cm long.

Amber Mountain Leaf Chameleon Brookesia tuberculata Amber Mountain NP.
I don't normally use photos of hand-held animals, but I'm sure you can see why I compromised here!
Barely 30mm long, it is close to being the world's smallest reptile.
It is also a stronghold for geckoes, with at least 110 known species (though that number is growing by the year); this is more than double the number for Australia, with 13 times the land area. A third of these are, unusually, daytime hunters.
Giant Day Gecko Phelusma grandis Ankarana NP.
Common Leaf-tailed Gecko Uroplatus fimbriatus Amber Mountain NP.
The camouflage of these leaf-tailed geckoes is truly astonishing.
There are just four snake families, including two of rarely-seen blind burrowers. The largest family is of mildly venomous back-fanged snakes, formerly grouped with the world-wide colubrids, but since 2010 included in the newly-recognised family Lamprophiidae, also widespread.
Madagascan Giant Hognose Snake Leioheterodon madagascariensis.This large snake grows to 180cm long, but specialises in digging up and eating lizard eggs with its tilted nose.
There are two species of boa, traditionally grouped with the South American boas, which posed some interesting questions, though that assessment is now in some doubt.
Madagascan Ground Boa Acrantophis madagascariensis, Isalo NP.
These are big hunters, up to three metres long.

Finally, for today, there are six bird families endemic to the island. One of these comprises just one species, the ancient Cuckoo-roller, which is also the sole member of its entire Order; to my disappointment this one evaded us. Another is a group of small warblers, only recently recognised as separate from more widely-spread warbler groups. Here are examples of the others.

The vangas (family Vangidae) are an astonishingly diverse group of hunters
which have evolved into 15 genera (with 22 species), filling every conceivable foraging niche
in every habitat on the island. This little beauty is Chabert's Vanga Leptopterus chabert, in the Ifaty spiny forest.

Sickle-billed Vanga Falculea palliata, Ankarana NP.
The ground-rollers (family Brachypteraciidae) comprise just six species in the same Order as true rollers. They are mostly ground-dwellers and elusive - we were lucky!
Scaly Ground-roller Geobiastes squamiger, Ramanofana NP.

Long-tailed Ground-roller Uratelornis chimaera, Ifaty spiny forest.
The mesites are more mysterious, just three species making up an entire Order in the family Mesitornithidae, probably most closely related to the sandgrouse (and, more distantly, pigeons). They are almost flightless.
Subdesert Mesite Monias benschi, Ifaty spiny forest.

Finally, there are the asities, a four-species family (Eurylaimidae) which, along with the pittas and broadbills, comprise the only members of the ancient Gondwanan sub-oscine passerines in the Old World; Madagascar never ceases to surprise!
Velvet Asity Philepitta castanea, Ranomafana NP; this is a non-breeding male.
So, just a brief outline of Madasagar - not too skimpy or disjointed I hope, and apologies for the lack of invertebrates. The island certainly deserves better, and as suggested earlier, we'll be back in posts to come! Thanks for being with me.

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Flabmeister said...

Your comment about the number of species of Vangas seemed very similar to statements I have read about the finches in the Galapagos. Is 22, rather than 42, the answer to everything?

Also wrt Vangas, do they appear in the anthropogenic desolation or just the more bosky reserves?

Ian Fraser said...

Perhaps not (re 22): I - or rather IOC - make the number of Gal 'finches' currently recognised to be 17.
A depressing truth about the 'anthropogenic desolation' (and what an evocative phrase is that - congratulations!) is that there are rarely any birds to see at all. Occasional Pied Crows or Mad Kestrels or Mascarene Martins or Common Mynas, but other than a few egrets there are not even any to be seen in the ubiquitous paddies. There are a few more in towns, but rurally it's all pretty bleak outside the reserves. Chabert's Vanga seems to the most common and adaptable vanga, but even those really only appear near to original vegetation; others only in forest.

Susan said...

The place obviously really had an impact on you. A great post and more to come I'm sure.

Ian Fraser said...

It did Susan! Both amazing and profoundly depressing. A most extraordinary part of the world, which we've treated very badly. But the reserves are wonderful, as are the local guides there. There will most certainly be more!

Lemur said...

thank you