Terrain shapes and bedrock
According to COUNTRYAAH, most of Madagascar consists of a centrally located highland with a north-south ridge, which lies to the east, parallel to the coast. The coastal area to the east is therefore narrow, about 50 km, and bounded to the highlands by a high and steep slope. The coastline here is strikingly straight, only with a deeper cut, the Gulf of Antongil in the north. The coastal plain has large lagoons, which are connected by a long canal, except at the far south where the coast is rocky.
The central highlands are located 900–1 500 m above sea level. and is composed of crystalline rocks such as granite and gneiss, which formed part of the Gondwana continent; Madagascar was separated from Africa during the Cretaceous period. The upland is largely made up of slanted plateau surfaces to the west. Above them rise three high masses, in northern Tsaratanana with Madagascar’s highest point Maromokotro (2 876 m above sea level), in the middle of the volcanic Ankaratram massif with the top Tsiafajavona (2 643 m ash) and in the south granite massif Andringitra with the top Pic Boby (2 658 m asl).
To the west, the plateau’s bedrock surface slopes slowly under sedimentary rock layers from Mesozoic and Tertiary times. Here it covers a 100–200 km wide topographic region, the inner part of which has sharp ridges. There is also a wider coastal plain with dunes and cliffs. The coastline is irregular with coral reefs and volcanic islands as well as estuaries in the north. In this western slope region there are a number of rivers that deposit large deltas, e.g. Betsiboka, Mangoky and Onilahy. Rivers in the steep eastern slope region are short and rich in cases like Maningory and Mananara.
There are several lakes of volcanic origin, e.g. Itasy on the western coastal plain and one, Alaotra, on the eastern slope. The terrestrial soil is mostly composed of laterite and other red soils. The valleys contain fertile soil that forms the basis for intensive agriculture.
According to BRIDGAT, Madagascar is completely within the tropical climate zone, but the elevation of the central plateau country means that it gets a warm-temperate climate with average temperatures for July at 13 °C and for January at 19 °C. The area east of this has a tropical rainforest climate of 21–27 °C and with a rainfall of up to 3,700 mm/year due to orographic reinforcement of the humid southeastern pass.
The western parts have savanna and steppe climate with rainy season during November – April, when the monsoon gives 2,000 mm in the north, while it falls 350 mm/year in the southwest.
Plant-and animal life
Both the flora and fauna of Madagascar are very different from those on the African continent. Of the vascular plants, about 85 percent of the species is estimated to be endemic.
The proportion of endemic species is also high among the animals. They are part of relatively few groups, and many other widely distributed animal groups are missing. Mammal groups that are naturally represented in Madagascar are semi-monkeys, tan rakes, wanderrides, rodents and bats. Two-thirds of all chameleon species in the world and the majority of species in the genus lizards live in Madagascar. However, there are no poisonous snakes.
In Madagascar, seven ecoregions have been identified: mangrove forest, deciduous dry forest, succulent forest, dry thorn forest, mountain rainforest, lowland rainforest and hard-leaf bush.
Since humans arrived in Madagascar about 2,000 years ago, about 90 percent of all nature has disappeared, which means that most plant and animal species and natural environments are threatened. This is a process that is still ongoing, which requires major conservation efforts to guard the great values that still remain.
Along the west coast, in particular, there are areas of mangrove forests protected from the northeast monsoon by Madagascar itself and from the ocean waves by nearby coral reefs. The mangrove forests capture sediment transported from land via the rivers, which otherwise threatens coral reefs and seagrass meadows. The most important areas are Bombeteka, Mahayamb Bay, Maintirano and Tsiribihina.
Animals such as dugong and nile crocodile prefer to seek out areas with mangrove forests. In addition, there are a couple of bird species that are specially adapted to these environments: Madagascar turtle (Anas bernieri), Madagascar heron (Ardea humbloti), Madagascaribis (Threskiornis bernieri) and Madagascar eagle (Haliaeetus vociferoides), one of the world’s rarest rare sack with. The Madagascar swallow (Glareola ocularis) and the Madagascar whip (Charadrius thoracicus) prefer to use the tidal areas around the mangrove forests.
Deciduous dry forest
Most of northwestern Madagascar is dominated by dry, deciduous forests where many trees lose their leaves during the dry season May – October. It is one of the world’s richest dry forest systems, with 70 percent of all plants endemic. From here originate among other things flamboyant, which is often grown as street trees in tropical countries. Unfortunately, only about 3 percent of the original nature remains.
Two species of lemurs are confined to these forests – one species of sifaka (Propithecus tattersalli) and mangustlemur (Eulemur mongoz). In addition, three Muslim walls are endemic and only live here. Fossa is the largest predator, and several species of turtles, chameleons, geckos and frogs live only here.
No less than 131 of Madagascar’s approximately 200 breeding bird species are found in the deciduous dry forests, such as giant coua (Coua gigas), green-backed asiti (Philepitta schlegeli), crocodile fang (Falculea palliata) and white-throated meadow (Xenopirostris damii). Among watercourses and ponds are found Madagascar heron (Ardeola idae), white-winged ibis (Lophotibis cristata) and Madagascarjacana (Actophilornis albinucha).
In the sea around the island of Nosy Be you will find one of Madagascar’s most valuable marine areas with whale sharks (November – January), spear dragon, manta and several species of sharks, including hammer shark. Unfortunately, many sharks are trapped and killed around Madagascar for the fins.
In addition to the lemurs, Madagascar is often associated with the tree baobab, which can be over 30 m high and often appears in pictures from the island. The species belongs in the succulent forest which forms a transition zone between the deciduous dry forest and the dry thorn forest. Here grows a mixture of deciduous trees and shrubs as well as species with thick, fleshy leaves, so-called succulents.
There are no less than eight different lemur species, three of which are largely confined to this part of the island (Phaner pallescens, Lepilemur ruficaudatus and Eulemur rufifrons). There is also the world’s smallest primate (Microcebus berthae), which is only found in the Kirindy Milea National Park. The ecoregion houses several endemic bird species, including long-tailed ground-blue crow (Uratelornis chimaera). Madagascar marsh (Circus macrosceles) has one of its main occurrences.
The farthest south of the ecoregion is dry thorn forest. The Didiereaceae family with cactus-like plants with small, thick leaves and thorns makes a special mark on the short-growing vegetation that rarely exceeds 3–6 m. No less than 95 percent of the plants are endemic.
The climate is extremely dry with a rain-free period that can be extended to 9-11 months. This places great demands on the adaptation of both plants and animals. Three charismatic lemurs have their only or main occurrence here: cats, siphas and the weasel machine Lepilemur leucopus. Several endemic birds are also found, such as light Madagascar carnivores (Nesillas lantzii), leprechaun (Coua cursor), verreauxkoua (Coua verreauxi) and black-tailed hawk (Xenopirostris xenopirostris).
Coast hedges here and there (eg on Nosy Manite) birds madagaskarpipare, roseate tern, greater crested tern (Sterna bergii) and lesser crested tern (Sterna bengalensis).
At Lake Erombo in the southeastern part are Madagascar droppings (Tachybaptus pelzelnii), Madagascar herons, flamingos and smaller flamingos (Phoenicopterus minor). The region, like so many other parts of Madagascar, is threatened by cultivation, livestock operations and the production of charcoal, although the threats are not as great here as in other parts of the island.
Along central Madagascar, a ridge stretches from south to north, and in areas above 900 m there are mountain rainforests. July – September is a dry period, while it rains regularly during the rest of the year (1,500–2,000 mm).
Unfortunately, very few areas of original nature remain, and the remaining are like islands in a landscape dominated by agriculture. To secure the few remaining areas, several reserves and five national parks have been set up (Andohakela, Andringitra, Midongy, Ranomafana and Zahamena – Mantadia).
When humans arrived in Madagascar about 2,000 years ago, giant giants such as gorillas and elephant birds were still living here. Today the fauna is extinct, but there are still over 20 endemic molluscs, at least 25 endemic reptile species (including several chameleons) and at least 45 endemic mammal species (some of which are also found in the lowland rainforest along the east coast). For example, around the Alaotras, live Alaotralemur (Hapalemur alaotrensis), which is adapted to live on papyrus and leaf reed.
A number of endemic bird species are also available, including Meller’s duck (Anas melleri), madagaskarbeckasin (Gallinago macrodactyla), multiple Coots (madagaskarrall Rallus madagascariensis, madagaskarskogsrall Canirallus kioloides and madagaskardunrall Sarothrura insularis) and cryptic singer (Crypto Sylvicola randrianasoloi).
In the lake Alaotra located in the northern part of the region, the last specimen of alaotra doping (Tachybaptus rufolavatus) was reported as late as 1982. The species has since been considered extinct. Madagascar brown duck (Aythya innotata), which also lived in the lake, was supposedly extinct in the 1980s, but was rediscovered in 2008.
Madagascar’s lowland rainforest extends along the entire eastern coast and from the sea level up to about 800 m altitude. It is the richest region in Madagascar.
Of the 165 breeding bird species, 42 are endemic, such as the Madagascar eagle (Eutriorchis astur), the Madagascar nugget (Tyto soumagnei), the red-tailed nightcrawler (Gactornis enarratus), the sunbird asiti (Neodrepanis coruscans), and the helmvangosta (Eurycer) There are also fifteen species of lemurs, including örontofsmaki (Allocebus trichotis), vitkragemaki (Eulemur cinereiceps), red-bellied lemur (Eulemur rubriventer), gyllenhalvmaki (golden bamboo lemur), diademed sifaka (Propithecus diadema) and the famous finger animal.
The Masoa Peninsula in the northern part houses the country’s largest national park and larger intact forests. Along the coast there are coral reefs and during July – September humpback whales visit sheltered places (for example the Gulf of Antongli) to feed their young.
Hard Sheet Shrubbery
At over 1,800 m altitude in the Madagascar mountain range, there are limited areas with hard-leaf bush. The flora is dominated by species within the families basket-flowering plants, heather plants, podocarpus plants, fallow plants and succulents. The ecoregion is recently separated and therefore lacks detailed information.
Madagascar had 20 national parks in 2010, among them Isalo in the southwest with, among other things, two species of lemurs and one species of cyphae, Montagne d’Ambre furthest to the north with tropical moisture forest and rich wildlife, and Ranomafana in the southeast with a full twelve species of semi-apes.
In addition, there were 23 reserves set aside to protect specific species or biotopes and five strict nature reserves with a ban on visitors.