Altitudinal and latitudinal distribution of east Malagasy forest bird communities

Aim To describe variation in forest bird communities with altitude and lati tude. Location Eastern Madagascar. Methods Extraction of data from forest bird in ventories conducted in eastern Madagascar. Results There is a strong decline in species richness with altitude, above about 1300 m. Below this altitude, species richness is about constant or de clines slightly. Seventy-eight percent of species occurring regularly in fo rest are absent from at least one of low, midaltitude or high altitude fore st. Of eighty-seven species occurring regularly in forest, only four or pos sibly five have latitudinally limited distributions, over a latitudinal ran ge of over 1200 km. Three or possibly four are limited to the northern two- thirds, and one appears to be at least much more common in the southern hal f. Main conclusions Eastern Malagasy rain forest birds show previously unanaly sed variation in altitudinal distribution. There is much less latitudinal v ariation. Species currently considered threatened are concentrated in the l owland and high-altitude zones. This may be at least partly due to lack of survey effort giving the impression that these species are rare, but lowlan d forests at least are under great human pressure. Bird conservation initia tives would probably have most effect if targeted at lowland east Malagasy rain forest.