What poses a risk to wildlife when granules are left on soil?

Leaving granules on soil poses a risk to wildlife, particularly through the potential for consumption by birds. Birds, being opportunistic feeders, may mistake these granules for food. If the granules are pesticides, herbicides, or fertilizers, ingesting them can lead to poisoning, reduced reproductive success, or even death in bird populations. The consumption of these substances disrupts not only the health of individual birds but can also have broader ecological impacts if other wildlife in the food chain is affected.

The other options present scenarios that do not directly relate to the immediate dangers posed by granules left on soil. Increased water retention mainly pertains to how soils manage moisture but does not impact wildlife significantly. The spread of disease usually involves pathogens rather than granular substances. Soil erosion refers to the physical wearing away of the land, which is a separate issue from the risks posed by granules. Thus, consumption by birds is the most pertinent risk in this context.