WOOD DUCK NEEDS

Wood duck requirements are a year-round process in California as we host a number of resident birds as well as a large proportion of wintering wood ducks in the Pacific Flyway. Like all wildlife, wood ducks have basic requirements that need to be met for survival.





Food
The diets of juvenile and adult wood ducks differ substantially. Early on in the life cycle the diet of juvenile wood ducks consists mainly of insects in addition to other high protein animal matter. As ducklings grow their food habits change rapidly, as they will opportunistically feed upon both plant and animal material in the surrounding habitat.

As adults, the diet of wood ducks varies depending upon the time of the year. During the spring, invertebrates and other animal matter comprise a higher proportion of the diet than at any other time of the year. In addition wood ducks will also readily consume a wide variety of plant material including acorns, grass seeds, duckweed, and agricultural crops. This diverse diet is extremely important to breeding hens, as this ensures adequate levels of nutrients necessary for the energetically demanding egg laying process. During the winter months the wood duck diet drastically changes as vegetative matter comprises up to 90% of the diet.

Water
Wood ducks use a variety of wetland habitats, including riparian forests, seasonal marshes, and permanent wetlands. In general, wood ducks use wetlands associated with streams and rivers more than any other habitat type. Water depth and flow are important aspects of habitat used by wood ducks, as these factors impact the quantity and quality of food and cover available to them. The needs of wood ducks are generally met near the shoreline, where they are able to exploit the resources of newly available food brought about by changing water levels. Even when in deeper waters wood ducks typically feed in only the top foot of the water column. Water flows of less than 1 mile per hour are considered optimal for both breeding wood ducks and broods.

Cover
Vegetative cover is important to wood ducks during all seasons, especially in avoidance of predators. Suitable cover can be provided by shrubs and downed trees overhanging the water. Downed trees also provide necessary loafing areas for birds. Emergent vegetation such as cattails and bulrush can also provide acceptable cover in the absence of trees and shrubs. Optimal cover for wood ducks exists when inundated vegetation covers 50-75% of the water area.

Nest Sites
The most important limiting factor for wood ducks is the availability of suitable nest cavities for reproduction. Wood ducks do not excavate their own cavities and must rely upon other animals such as woodpeckers or natural processes such as rot to provide nest sites. Nest cavities must be large enough to accommodate the medium sized wood duck hen, in addition to a clutch of approximately 12 eggs. With that in mind, mature forests are needed for the development of suitable trees with cavities. Unfortunately with the destruction of over 95% of California’s forested riparian habitats, significantly less mature forest remains today. Nest boxes can be a useful management tool where natural cavities are scarce but other habitat components remain intact.