Habitat distribution in the desert snail Trochoidea seetzenii

In the N Negev Desert, Israel, the authors studied individual movement in a wadi and the lower slope of the same watershed. In winter, after the first heavy rains, snails moved from the wadi to the slope until snail density was similar in the two habitats. In the late rainy period the opposite trend in movement resulted in higher density in the wadi relative to the slope. The temporal changes in the density distribution are mainly the effect of the snails moving between habitats so that they maximize reproduction in winters and survival in summers. -from Authors