The Wood Thrush and the Land Snail

The Wood Thrush’s song rings throughout the forest. Their cinnamon brown upper body is good camouflage as it scrabbles for leaf litter invertebrates deep on the forest floor. The Wood Thrush is rapidly declining in the Eastern deciduous forest due to the depletion of its invertebrate prey, the White-lipped land snail. Calcium-rich foods like the snail shells are essential nutrients for egg-layers like the Wood Thrush. Reduced soil calcium is due to acid rain thinning the eggshells.

Land snails obtain calcium from their environment. To make its shell, a snail gathers calcium either from its food or directly from the soil by absorbing it through its foot. They are prey to a number of larger animals and can be used to determine the quality of their habitat.

Acid rain causes calcium to leach from the soil. Aside from depleting calcium, acid rain in soil can promote increased levels of toxic aluminum, cadmium and lead. Polluted soil may slow the decomposition of leaf litter, which reduces the diversity and abundance of prey.