The Use of Artificial Nests as an Index to Nest Success in
Upland-nesting Ducks
V. L. KURNAT AND I. J. BALL
Montana Cooperative Wildlife Research Unit, University of Montana,
Missoula, MT 59812
Ground-nesting ducks often suffer high nest mortality, frequently having success rates that are insufficient to maintain recruitment at a level capable of sustaining stable populations. Predation accounts for 75-85% of nest failures. We are attempting to develop an index to natural nest success that will facilitate data collection and alleviate the disturbance to hens and habitat associated with nest searching. Researchers have used artificial nests in a variety of studies to investigate the relationship between habitat structure and nest success. However, the relationship between artificial and natural nest success has not been clearly established, particularly over a large geographic range with diverse predator populations.
During the 1989 and 1990 nesting seasons, we placed over 1,500 artificial nests on 11 sites throughout Montana. One-half of each sample was scented with commercial scent disks to determine whether scented nests attracted a more representative sample of mammalian and avian predators than unscented nests. In 1989, the natural nest success on nine sites ranged from 0 to 96%, while artificial nest success ranged from 4 to 96%. Preliminary plots of the data suggest that the relationship between natural and artificial nest success is significant, but with substantial variation. The exact relationship will be determined through regression analysis upon completion of the 1990 nesting season.
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