Habitat Use and Movements of Canvasback Broods in Southwestern Manitoba

Abstract:  Canvasback (Aythya valisineria) broods (n = 69) accompanying marked females were observed during five summers in southwestern Manitoba. We evaluated movements of broods of different age classes (≤14 days old, 15-28 days old, and >28 days old) among ponds of different size and wetland class. Of 202 brood sightings, 7% occurred on seasonal ponds, 81% on semipermanent ponds, and 12% on permanent ponds. Pond size (≤0.2 ha vs. >0.2 ha) was a significant factor in brood use whereas wetland class was not. Canvasback broods used larger ponds as brood age class increased. Broods moved an average of 195 m between sightings. Eighty-three percent of broods observed within seven days of hatching (n = 46) had moved from the nesting pond. No significant differences in frequency or distance of movements were detected among years or among brood age classes. Extensive movements among ponds of various sizes and classes emphasize the importance of wetland complexes for providing diverse habitats needed for nesting and brood-rearing canvasbacks.

Key words: Aythya valisineria, broods, canvasback, habitat use, movements, Manitoba

Table of Contents

• Introduction
• Study Area and Methods
• Results and Discussion
• Literature Cited

Tables

• Table 1 -- Use of different sizes and classes of wetlands by canvasback broods.
• Table 2 -- Mean distance moved per day by canvasback broods of different age classes.

Acknowledgments

The study was funded by the U.S. Fish and Wildlife Service. D. L. Trauger and J. R. Serie designed and conducted the field work. Field assistance was provided by R. Bromley, J. Cameron, L. Deede, T. Fondell, D. J. Johnson, M. R. Miller, J. H. Noyes, G. Simard, and L. W. Vanderhoef. M. G. Anderson and the Delta Waterfowl and Wetlands Research Station provided assistance throughout the study. Detailed measurements of movements were provided by R. Emery, Delta Waterfowl and Wetlands Research Station. T. L. Shaffer and D. J. Twedt provided statistical assistance and review. We appreciate the insight, advice, and editorial comments of R. R. Koford, C. E. Korschgen, G. L. Krapu, J. R. Lovvorn, and J. T. Lokemoen.