Why are true moles absent from the Great Plains and western deserts of North America?

While true moles (family Talpidae) are found in both the eastern and western portions of North America, they are absent from the Great Plains and western deserts.1

The primary reason for this distribution is that true moles are specialized for environments that provide soft, moist soil, which is essential for their burrowing lifestyle and their diet of invertebrates like earthworms. The Great Plains and western deserts generally lack the consistent soil moisture and the specific subterranean prey density required to support these animals. Unlike some other fossorial mammals that are adapted to arid or open prairie conditions, true moles rely on their ability to construct complex tunnel systems in soil that remains stable and productive enough to sustain their high metabolic needs.12