Newly constructed wetlands and islands in old and new reservoirs are usually sparcely vegetated for the first few years. Consequently, this vegetative cover may be insufficient to provide adequate cover for successful duck nesting. Additionally, due to poor soil, high alkalinity, and other factors, these areas may never produce sufficient vegetation to provide the cover and concealment required for the nest itself. Artificial nesting materials in the form of brush piles, when correctly constructed and located, provide nesting cover and protection as would a good stand of natural vegetation.
Brush piles provide:
- Concealment from predators - an overhead canopy and surrounding brush hide eggs from the view of predators.
- Protection from predators - the tight network of strong twigs and the small opening eliminate entry by most predators.
- Protection from the elements - nests are sheltered from the cooling rains, wind and direct sunlight.
- Harbor for various seeds to sprout in - the network of twigs and grass provide a medium for seed germination and young plant protection.
- A chance for brush and tree species to establish - using green branches for the construction of the brush piles in muddy areas allows sprouting and development of the brush and tree trimmings used.
Various species of dabbling ducks will be the major nesting inhabitants of the brush piles, although a few species of smaller birds may utilize the available sites.