This EBA in Madagascar skirts and penetrates the West Malagasy dry forests (EBA 093), extends south into the South Malagasy spiny forest (EBA 097), and includes wetlands adjacent to the Sambirano rain forest (included in EBA 094).

A variety of habitats is present within the EBA, ranging from sandy coasts and islets, rocky coasts, mangroves, salt pans, mudflats and river mouths, to inland lakes and lake shores. The limits of the EBA are based on a vegetation map by Du Puy and Moat (1996), and include all of the western and southern coastline, all significant patches of mangrove and marsh, and the mouths and deltas of major rivers. Because the wetland habitats are patchy (and many may be too small to feature on the map used), it has been difficult to define the boundary of the EBA, and some of the restricted-range birds may occur outside the area shown.

There is no particular pattern in the distributions of the EBA's restricted-range species. Ardea humbloti is the most widespread in the EBA, from Antsiranana in the north to Tolanaro in the south, and has also been recorded in areas beyond the limits of the EBA, including Madagascar's high plateau and east coast (EBA 095, although these records usually involve immature individuals), and in the Comoro Islands (EBA 098, where it possibly breeds).

Haliaeetus vociferoides, Anas bernieri and Actophilornis albinucha share similar coastal distributions between Antsiranana and Morombe, although H. vociferoides also occurs at Lake Maudit in the Montagne d'Ambre National Park and immatures may wander beyond these limits. Amaurornis olivieri is known only from a few sites between Mahajanga and Morombe, while Charadrius thoracicus occurs mainly in the west and south, between Soalala and Tolanaro, although it is also infrequently reported from the east coast. Anas melleri is largely a species of the East Malagasy wetlands (EBA 095), and in the present EBA is known only from a few sightings including ones at Bemamba and Kinkony lakes.

Madagascar Sacred Ibis Threskiornis aethiopicus bernieri is a bird of shallow lakes, estuaries and exposed sand bars, also confined to this EBA. It was considered a full species by Sibley and Monroe (1990) but given subspecific rank by Sibley and Monroe (1993) and has not been included in this study.

Madagascar has experienced natural desiccation over the past few thousand years and wetland habitats have thus long been in decline (Langrand and Goodman 1995). The problem is compounded by the conversion of surviving relicts to rice paddy (which is taking place extremely rapidly with the arrival of rice-growing immigrants from the east), and siltation due to watershed deforestation. Additional threats to some species are the introduction of alien fish (which considerably limit the development of aquatic vegetation), hunting, and the cutting of mangroves for fuel.

Wetland degradation is a cause of major concern for Anas bernieri, a species which does not use ricefields but only areas of shallow water over mud, the habitat type preferred for agricultural conversion (Young et al. 1993; see also Safford 1993a); also for Amaurornis olivieri, which had not been seen since the mid-1970s until reported from Lake Bemamba in 1995 (Ramanampamonjy 1995). Haliaeetus vociferoides survives in extremely low numbers, estimated at 100 breeding pairs; habitat alteration (loss of both nesting and foraging habitat) and direct persecution have been identified as the major threats to the species (Watson et al. 1993). The single most important concentration of 10 pairs breeds on three adjacent lakes-Befotaka, Soamalipo and Ankerika-near the southern end of the species' range; fishing is the main livelihood of local Sakalava tribespeople who have harmoniously shared these wetlands with fish-eagles for centuries, but recently there has been a massive influx of migrant fishermen who do not share the same traditional resource extraction rules (Watson and Rabarisoa in press).

In general, mangroves, wetlands and coasts have little legal protection; the strict nature reserve which includes Lake Tsimanampetsotsa (60 km²) is one exception (Langrand 1990; see also Langrand and Wilmé 1993), although this soda lake has little importance for restricted-range species apart from Charadrius thoracicus (A. F. A. Hawkins in litt. 1996). In order to assess and prioritize suitable wetlands for protection, a monitoring procedure has been proposed using birds as indicators, e.g. Madagascar Grebe Tachybaptus pelzelnii, a widespread threatened species (classified as Vulnerable), and Haliaeetus vociferoides (Langrand and Goodman 1995).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: West Malagasy wetlands. Downloaded from https://datazone.birdlife.org/eba/factsheet/112 on 22/11/2024.