Terrestrial

Physical Environment

Topography

The west coast of Madagascar is made up of sedimentary formations deposited in multiple layers over time. The broad alluvial plains found along the west coast, from Mahajanga to Toliara, are believed to have great agricultural potential but remain sparsely populated and largely unexploited.

Since ancient times, traders and pirates from Europe, Africa and the Middle East have been drawn to the region's deep bays and well-protected harbours, making the west coast an important bridge between Madagascar and the outside world.

There is no significant river flow or associated sediment within 100 km of Andavadoaka. This is because rivers that flow to the west coast tend to be longer and slower, due to the gradual slope of the land. The major rivers along the west coast are the Sambirano, the Mahajamba, the Betsiboka, the Mania, the North and South Mahavavy, the Mangoky and the Onilahy.

The west coast is lined by more than 300 km of well-developed fringing reefs, barrier reefs, patch reefs and submerged coral bank formations stretching from below Toliara in the south to Antsiranana in the north.

Geology

The major rock type of the Andavadoaka region is limestone, which begins from the fringing coral reefs and follows up into the spiny forest.

Ecosystems

Ecosystems

Spiny forests

Deescribed by some as the "eighth wonder of the world", these are the main vegetative type in this ecoregion.

An odd combination of desert and forest, spiny forests are endemic to Madagascar's south west coastal areas, one of the only vegetative communities able to survive the extreme arid climate of the region. Plants here can go without water for more than a year.

Spiny forests are comprised primarily of plants of the Didiereaceae family, which look similar to some cactus, although they are not related.

Plants in the Didiereaceae family have bulbous trunks and small deciduous leaves which are protected by thorns and spines that grow out of the plant's tangled branches. The "octopus tree" is one aptly named plant in this family.

Other plants found in these forests are evergreen succulents, baobab trees and endemic orchids.

Spiny forests are extremely threatened, being destroyed for charcoal production and building materials.

Baobab Trees

Baobab trees are one of Madagascar's most striking attractions due to their large size and extremely unusual appearance.

Resembling massive brown paper bags filled with water, their bulbous trunks can grow up to 10 metres in diametre and up to 30 metres tall. The sparse branches are located only at the very top of the tree.

There are eight baobab species in the world, six of which are endemic to Madagascar. Baobabs are extremely long lived. Scientists once believed they could live to be 3,000 years old, although recent studies now estimate the oldest trees to be no more than 600 years old.

Baobabs can store thousands of litres of water in their trunks, which allows them to survive during the lengthy dry seasons.

Baobabs are extremely important to local communities. The bark is used to build huts and make rope; their fruits and leaves, which are rich in calcium, are eaten; the seeds are crushed to extract oil which is used to make soap; and the sap is used in manufacturing paper.

The hollow trunks of baobabs have served as homes, storage barns, places of refuge or worship, prisons and tombs.

 

 

Fauna

Fauna

The Andavadoaka region is home to a wide variety of strange and unique animals, including a number of species found no where else on earth.

Three mammals are endemic to the region: the white-footed sportive lemur (Lepilemur leucopus), Grandidier’s mongoose (Galidictis grandidieri) and the gray-brown mouse lemur (Microcebus griseorufus), one of the world's tiniest primates. A variety of chameleons are also unique to the area.

A number of species are listed as endangered or threatened, such as the ring-tailed lemur and Verreaux’s sifaka, a lemur known for its amazing leaping skills.

Tenrecs

About 30 species of tenrec live in Madagascar -- more than any other place on earth. Tenrecs are an unusual species of small insectivores that can vary widely in color, size and body cover. They are active mainly at night and hibernate for three to five months during the cold season.

A variety of tenrec species make their home in the Andavadoaka region. The large-eared tenrec (Geogale aurita) is a shrew-like creature measuring less than 100 mm. The lesser hedgehog tenrec (Echinops telfairi) is covered in spines and curls into a spikey ball when threatened.

Chameleons

With 59 species, Madagascar has one of the largest and most diverse chameleon populations in the world.

Chameleons are known for their ability to change colour from brown to blue to red, black or white. These changes occur in response to temperature, light and mood. Chameleons also use colour to communicate, expressing such things as their willingness to mate.

Among the species that are endemic to the Andavadoaka region are Furcifer belalandaensis and F. antimena.

Tortoise

The two most populous species of tortoise found in the Andavadoaka region are the spider tortoise (Pyxis arachnoides) and the radiated tortoise (Geochelone radiata).

Weighing up to 35 pounds (16kg) with high-domed shells that can grow up to 16 inches (41 cm) long, the radiated tortoise is considered one of the world's most beautiful tortoises. Its shell is marked with yellow lines radiating from the center of each dark plate of the shell.

Radiated tortoises are severely endangered due to habitat loss, being hunted for food and use in the pet trade. When captured, they emit high-pitched cries that sometimes last for as long as an hour.

Iguanids

Two iguanid species are endemic to the Andavadoaka region: the rock-dwelling Oplurus saxicola, which can grow up to 20 cm long, and the Chalarodon madagascariensis which can grow up to 40 cm in length. Both these species are part of the Oplurinae family and live in subhumid to arid areas.

Geckos

Two species of gecko, small lizards, live in the Andavadoaka region: Hemidactylus frenatus and Paroedura Bastardi. They are active by day and have brightly coloured green, orange, red or blue spots. They are well-known for their vocalizations (chirps) used to communitcate with other geckos.

Amphibia

Frogs are the only Amphibia found in Madagascar with over 300 species, 99 percent of which are endemic.

Birds

There are 270 bird species in Madagascar, 109 of which are found no where else on earth. Of these, there are five endemic families and 36 endemic genera, making Madagascar the hot-spot for bird endemism in Africa. Birds found in and around Andavadoaka are: Corvus Albus (Pied Crow), Oena Capensis (Namaqua Dove), Acridotheres tristis (Common Myna), Charadrius marginatus

(White-fronted Plover), Numenius phaeopus (Whimbrel), Arenaria interpres (Ruddy turnstone), Cailidris ferruginea (Curlew Sandpiper), Egretta dimorpha (Dimorphic egret), Numenius phaeopus (Whimbrel), Calidris Alba (Sanderling), Cailidris ferruginea (Curlew Sandpiper), Grey heron, Tringa nebularis (Common Greenshank), Charadrius tricollaris (Three-banded plover), Himantopus himantopus (Black-winged stilt), Bubulcus ibis (Cattle Egret), Neomixis striatigula pallidior (Stripe-throated jery), Schetba vanga (Rufous vanga), Foudis madagascariensis (Madagascar Red Fody), Flamant Rose (Greater Flamingo), Mirafra hova (Madagascar Bush Lark),

 

Falco newtoni (Madagascar Kestrel) Agaporuis cana (Grey-headed lovebird), Herops supercilious (Madagascar bee eater), Cisticola cheviva (Madagascar cisticola), Egretta avdesiaca (Black Heron), Upupa epops (Madagascar Hoopoe), Haliaeetus vocifer (African fish eagle), Calidinis animata (Little Stilt), Dicrurus forficatus (Crested Drongo), Ringed Plover, Saka Lava Rail, Lesser crested tern, Souimanga Lovebird.