. Species richness and density in the fragmentsA total of 32 amphibian species belonging to all three amphibian families known from Madagascar — Hyperoliidae, Ranidae (including the subfamilies Raninae, Rhacophorinae and Mantellinae) and Microhylidae (including the subfamily Cophylinae) — were present in Ambohitantely (Table 2). Four of these species were only found outside the rainforest (Heterixalus rutenbergi, Mantidactylus cf. alutus, M. domerguei and Ptychadena mascareniensis). Two species were found in the pseudosteppe as well as in the rainforest (Boophis goudoti and Mantidactylus betsileanus). The other 26 species were found exclusively inside the rainforest. Hyperoliidae and Raninae were recorded outside the rainforest whereas Rhacophorinae and Mantellinae live both inside and outside the rainforest. The Microhylids were found only inside the rainforest ( Table 2). The number of species in a fragment increased logarithmically with increasing area size (Spearman, n=7, rs=0.937, P<0.01) following the formula: S=11.00A0.108 (S=species number, A=fragment size) ( Fig. 2). Only nine out of all 28 rainforest species were present in the smallest fragment while the control site contained 26 species. Two species (Boophis microtympanum and Mantidactylus brevipalmatus), only found once in two small fragments, were not found in the control site ( Table 2). An increasing diversity with increasing fragment size is also indicated by the Shannon-Index (Spearman: n=7, rs=0.892, P < 0.05) ( Fig. 2
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