What might be responsible for the damage to the bark and roots of a shrub?

In this context, voles are small, burrowing rodents known for causing specific types of damage to plants, particularly to the bark and roots of shrubs. Voles have strong teeth that allow them to gnaw on the bark and can cause significant issues by removing the outer layers of a shrub's bark. This can lead to girdling, ultimately harming the plant's ability to transport nutrients and water, potentially resulting in its decline or death.

While other animals listed can also damage plants, voles are particularly notorious for targeting the underground parts of shrubs, feeding on roots and gnawing at the bark near the soil line where they are most active. Their feeding habits can severely compromise a plant's stability and health, which is why they are the most likely cause of such damage in this scenario.