@VC, I will do both, the first 4 months will be an internship, the last month I will spent travelling trough the island.
@AD, The Malagasy language has neven been well-known for it's concise and short names. It almost seems a kind of a sport to create the longest name possible....
And for all the people who do not know what endemic means, a species that is endemic for Madagascar, worldwide only occurs at Madagascar. You will see this term a bit more in this post
Wildlife in Madagascar
Madagascar is most well-known for it's impressive biodiversity and the absurd high levels of endemism from the approximate 200.000 species found in Madagascar, most are endemic, in some species groups endemism level is over 95%. The reason that Madagascar has such high biodiversity and endemism levels are explained by the fact that there is a huge range of different habitats available and the island is not easily reached.
Natural history and landscape
Until 167 million years ago Madagascar was connected with Gondwanaland, but together with India it split of from African and since 65 million years ago it is an island on it's own and the "evolutionary experiment" begun. It's original stock consisted of species groups like boas, iguanas, cycads and ferns. On the bigger continents in the old world boas were replaced by pythons, but in Madagscar pythons have never arrived. In the past 65 million years only very few species have made the ocean crossing to Madagascar and only these "elite" species groups now occur on Madagascar. Most of them have been replaced on mainland Africa by better adapted species, like the python example. But Madagascar proved to be a safe haven.
Madagascar basically consists of 3 main ecosystems. In the east there are tropical rainforests, in the west dry decidious forest and in the south/southwest an arid, almost desert like spiny forest exists. This is because there is a large mountain ridge running from north to south with peaks up to 2800 meters that keep the rain mostly on the east side of the country. Exept in the rainy season which coincides with the boreal winter, in this rainy season the arid parts get only 50 to 340 mm rain per year, but over 4000 mm per year is normal in the north east.
This huge precipitation gradient, together with the gradient in altitude and the fact that there are several large rivers/ mountain ridges that function as barrier make that Madagascar was able to develop such high biodiversity levels.
Plants
about 13.000 plant species have been recorded from Madagascar, of which 89% is endemic. There are even 8 plant families that are totally endemic to Madagascar. Among them is the Didieraceae family, which are the Malagasy cactuses.
Most famous however are the baobabs and orchids. 6 from the 8 baobab species live solely on Madagascar (the other 2 in Africa and Asia) and they are sometimes main tourist attractions.
Madagascar has an immense species richness in orchids, almost a 1000 species are known to occur on Madagascar, of which the vanilla orchid is the most well known. Madagascar is the number 1 producer of vanilla and it is also the biggest export product.
Other interesting plant species groups include the
Pachypodium (Madagascar has 20 out of 25
Pachypodium species, all endemic),
Euphorbia and palms. Palms are another rather primitive group that has survived on Madagascar, with 3x more palm species occuring on Madagascar, than on the whole mainland Africa, and over 95% of the Malagasy palm species is endemic. Also interesting are the 2 endemic species of pitcher plants (
Nepenthes), a meat-eating group that further only occurs in SE-Asia.
Invertebrates
As usual the invertebrate animals take up the biggest part of biodiversity and endemism levels are high as usual in most groups. But from the 300 butterfly species, only 70% is endemic. Most well known species include the giant millipedes and the comet moth (google him).
There are not that much "nasty" species on Madagascar, all the nasty ones are invertebrates and include 40 species of scorpions, black widow spiders and the malaria mosquitoes. But the other side is that there are no venomous snakes and large mammal predators to watch out for.
But the most interesting species group in Madagascar is for sure the
Gastropoda, the land snails, of which 95% is of course endemic. But more about them in a later post.
Amphibians
From the main amphibian groups, only the frogs have ever reached Madagascar. But there has been a huge radiation ever since and from the over 300 species, all but 2 occur only on Madagascar. And there are new frog species discovered on a yearly basis. Very recently about 30 new species were discovered in a tiny rainforest fragment of 2200 hectare, the Betampona reserve (
Mad frog bonanza: up to 36 new frogs discovered in tiny Madagascar forest). But also more about Betampona later on, as I will stay there 4 months.
The most well-known frog species are the tomato frogs and mantellas, Madagascars equivalent of poison dart frogs.
Reptiles
The reptile array is more complete, although a few species groups dominate. With almost 350 species occuring in Madagascar, Madagascar is in the top-10 of worldwide reptile diversity, and of course 92% is endemic to Madagascar
There are nile crocodiles in Madagascar, although an endemic subspecies not a real endemic. But the crocodiles are getting rare and only occur in the western part of the country.
Tortoises and turtles are also present, exept the sea turtles, 8 species occur on Madagascar, 4 endemic tortoises and 4 turtles, of which one is endemic. The Ploughshare tortoise is one of the most endangered tortoises in the world and very high sought after in the ilegal trade. But Durrel has set up a breeding station in Madagascar and the species recently found it's way to European zoos.
over 80 snake species occur on Madagascar, none are dangerous to humans. The 3 boa species are well known as these are a relict from the past. The Madagascar hognose snake and the leaf nosed snakes are also well known Malagasy snake species.
Lizard diversity is high in Madagascar with over 200 species with chameleons and geckos as star species. But monitor lizards and agamas did not make it to the island.
about 50% of all chameleon species lives in Madagascar, this approx. 80 species are divided in 3 genera:
Brookesia,
Furcifer and
Calumma. Brookesia chameleons are very small terrestrial chameleons that look like a leaf, the other 2 genera also include larger species, of which the Parsons chameleon can grow up to 80 cm.
Gecko's come in different groups, the day active
Phelsuma and the night active
Uroplatus are the bigger groups. Other lizard species on Madagascar are the 4 iguana species (endemic family
Opluridae), skinks and plated lizards, of course also represented by Malagasy endemics.
Birds
Technically spoken also reptiles, but I will treat them separately
Bird species richness is not as high as in other tropical islands, partly because of the distance to the mainland. But about 220 species breed on Madagascar and over half is endemic to Madagascar and 22 further species only occur on the Indian Ocean islands. Many bird orders are represented on Madagascar but not with high species numbers.
Madagascar does have it's specialities: the 4 asity species constitute an endemic sub-family, the 5 ground roller species are even an endemic family, as are the mesites. Another Madagascar group are the coua's, this cuckoo genus has radiated intoo 9 distinct species. But of course Madagascar also has it's own "Darwin finches": the vangas (
Vangidae. All 22 species are endemic, exept one species occuring on the Comoros. The vanga family shows a huge radiation in size and beak form and many niches are occupied by vangas in Madagascar. Google for example the helmet vanga, blue vanga, hook-billed vanga, sickle billed vanga and ward's vanga, to get an idea of the radiation.
Mammals
The mammal fauna is remarkable and there are almost 200 mammal species occuring on Madagascar. The native mammal fauna comprises lemurs, tenrecs, mice & rats, Malagasy carnivores and bats. Exept for some bat species all mammal species are endemic to Madagascar.
the 28 tenrec species have undergone a wide radiation and fulfil all the insectivore niches on the island, there are shrew-like tenrecs, mole-like, hedgehog-like and even otter shrew-like tenrecs.
The lemurs are the star species of Madagascar and 98 lemur species are recognised at the moment. The Malagasy lemurs are the only day active prosimians left, as the monkeys did not make it to Madagascar. There are 5 distinct families of lemur on Madagascar: the mouse & dwarf lemurs (
Cheirolagidae, sportive lemurs
Lepilemuridae, true lemurs
lemuridae (including ring tailed lemur, vari, bamboo lemur and other true lemurs),
Indridae (Including sifaka, indri and avahi) and the Aye Aye has it's own family (
Daubentonidae).
the first 2 families together comprise 60 nocturnal species, most of them have only tiny distributions and are described very recently. The true lemurs are very well known and together with sifakas and indris the only diurnal primate species on the island. The sifakas are divided in 9 species, all separated geographically. This is normal in lemurs and narrowly related species only vary seldom overlap.
The malagasy carnivores (
Eupleridae, consist of 9 endemic species, all with the same ancestor. There are huge size differences from the large fossa to the small ring-tailed mongoose, the carnivores have taken the roles of african mongooses, civets, small cats and the Falanouc has specializes on ants.
The native rodents all belong to the endemic subfamily
Nesomyinae, containing "only" 24 species, of which the giant jumping rat is the most well known.
From the 36 bat species, 24 are endemic. There are 3 endemic megabats, a fruit fox, a rousette and a straw coloured fruit bat. The other species are insect eaters. The Commerson leaf nosed bat and the sucker-footed bats (endemic family
Myzopodidae) are worth mentioning.
Unfortunately there are a few non-native species occuring on Madagascar, 2 species of shrew, indian civet, the house mouse, both problematic
Rattus species and the bush pig. It is still debated whether the bushpig is native or not, but it was probably introduced by humans. In the past there were also pygmy hippo like species occuring on Madagascar, but these were wiped out by humans 1000 years ago.
So far for the introduction, it should now be clear why Madagascar is a biologist dream and why I wanted to visit Madagascar. In the next post I will introduce what I will be doing
.
