REPTILES AND BREEDING BIRDS ON MT. HERMON: PATTERNS OF ALTITUDINAL DISTRIBUTION AND SPECIES RICHNESS

Abstract

ABSTRACT We review and analyze the altitudinal distribution of reptiles (from museum collections) and breeding birds (from literature records and a recent field sampling project) on Mt. Hermon (latitude ca. 33°30′N), over the range 300–2814 m. Species richness was greater in breeding birds (n = 86–90) than in reptiles (n = 34), declining with increasing altitude in both groups, but more steeply so in birds. We suggest that the simplification of vegetation structure with increasing altitude may explain this difference, because birds probably better use the three-dimensionality of densely-vegetated habitats that dominate low elevations. But in both taxa the overall decline was nonlinear; species richness actually increased from low to mid-elevations, forming a hump-shaped pattern. Standardization of species richness for surface area, across altitudinal belts of 100 m up to 1,900 m, revealed the area effect as both significant and unpredictable. It did not affect the overall decline, but contrary to a genera...