This EBA corresponds to the Southern Domain of the Western Malagasy Region in Madagascar (a biogeographic region recognized by White 1983), where the vegetation is deciduous dry (spiny) forest and thorny scrubland, and the most characteristic plants are the Didiereaceae (an endemic family) and arborescent euphorbias.

The northern (inland) boundary of the EBA has been drawn to include all remaining habitat, largely below 500 m, running southward from Morombe, along the coastal strip to just west of Tolanaro; forest cover is based on satellite imagery of the vegetation taken between 1971 and 1979, these data being simplified and interpreted by Du Puy and Moat (1996) from Faramalala (1988, 1995). The southern (coastal) boundary skirts coastal wetlands that are included in the West Malagasy wetlands (EBA 096), which also intersects the present EBA along rivers.

Several species have very small ranges. For example, Monias benschi and Uratelornis chimaera (both in monospecific genera) are very local, being distributed only in the northernmost part of the EBA, along a narrow coastal strip 70 km wide by 200 km long. The recently described Calicalicus rufocarpalis is currently known only from the Toliara region, while Coua verreauxi is only known from the south-west.

Thamnornis chloropetoides and Newtonia archboldi are now both known to occur c.100 km north of the northern limits of this EBA in the West Malagasy dry forests (EBA 093), but the cores of their ranges remain in the present EBA.

The spiny forest is the most nearly intact of Madagascar's climax vegetation types because it is largely found on poor substrates and/or where the climate is least suited to cultivation. Recent estimates from satellite imagery suggest between 14,000 and 17,000 km² remaining (Nelson and Horning 1993, Du Puy and Moat 1996).

The principal threat to the region comes from the collection of wood for conversion to charcoal for fuel, particularly near major urban areas (Jenkins 1987, Langrand 1990), but there are also significant problems with clearance for cultivation (mainly maize), degradation through grazing by cattle and goats (of unknown long-term effect), and timber exploitation for commercial construction (A. F. A. Hawkins in litt. 1995). Monias benschi and Uratelornis chimaera are classified as threatened on account of their very restricted ranges, and are also threatened by hunting.

There are four strict nature or special reserves in this EBA, including the Beza-Mahafaly Special Reserve, which gives protection to some restricted-range species, and Lake Tsimanampetsotsa Strict Nature Reserve, which includes an important area of euphorbia forest. Berenty Private Reserve and the forest north of Toliara have also been identified as important sites by Langrand (1990), the latter because of the occurrence of Monias benschi and Uratelornis chimaera. Du Puy and Moat (1996) calculate that only 2% of the remaining deciduous, dry, southern forest and scrubland is well protected, and identify this vegetation type as having the most outstanding need for additional reserves in Madagascar.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: South Malagasy spiny forests. Downloaded from https://datazone.birdlife.org/eba/factsheet/113 on 22/11/2024.