Wood duck production and habitat use

Abstract

During 1977 through 1979, data on the nesting and hatching success of wood ducks (Aix sponsa) were collected from 32 wood duck nesting boxes in east-central Texas. All boxes were located in areas devoid of brood rearing habitat. During 1978 and 1979, additional data were collected on wood duck brood movements, survival, and habitat use. Sixty-seven clutches were initiated with an average clutch size of 14--3 eggs per clutch. Three hundred forty-six ducklings from 39 clutches exited nest structures. The nesting season lasted from mid-February through early August. Movement data from 20 broods indicated most broods left the nesting site immediately after exiting nesting structures. Movements radiated in all directions and crossed several habitat types. Distances traveled in moving from nesting site to brood rearing site varied from 0.1 km to 11.7 km. Survival data for 18 broods indicated an overall survival rate of only 8%. However, a 48% survival rate was calculated from 5 broods successful at reaching adequate brood rearing habitat. Wood duck brood use and survival increased with an increase in wetland size, length of shoreline, percent floating and emergent vegetation, and percent flooded shrubs. Use and survival decreased with increased water depth and percent open water. Wood duck production could be increased by removing or replacing artificial structures which are now in areas unsuitable for brood development and are at excessive distances from such areas.