Anthony, R.M., Grand, J.B., Fondell, T.F. & Miller, D.A. 2006: Techniques for identifying predators of goose nests. - Wildl. Biol. 12: 249-256.
We used cameras and artificial eggs to identify nest predators of dusky Canada goose Branta canadensis occidentalis nests during 1997-2000. Cameras were set up at 195 occupied goose nests and 60 artificial nests. We placed wooden eggs and domestic goose eggs that were emptied and then filled with wax or foam in an additional 263 natural goose nests to identify predators from marks in the artificial eggs. All techniques had limitations, but each correctly identified predators and estimated their relative importance. Nests with cameras had higher rates of abandonment than natural nests, especially during laying. Abandonment rates were reduced by deploying artificial eggs late in laying and reducing time at nests. Predation rates for nests with cameras were slightly lower than for nests without cameras. Wax-filled artificial eggs caused mortality of embryos in natural nests, but were better for identifying predator marks at artificial nests. Use of foam-filled artificial eggs in natural nests was the most cost effective means of monitoring nest predation.
Key words: Alaska, artificial egg, Branta canadensis occidentalis, camera, dusky Canada goose, nest predator
Present addresses:
*Alabama Cooperative Fisheries and Wildlife Research Unit, School of Forestry and Wildlife Sciences, 108 White Smith Hall, Auburn University, Auburn, AL 36849, USA
**Department of Natural Resource Ecology and Management, Iowa State University, 124 Science II, Ames, IA 50010-3221, USA
Corresponding author: R. Michael Anthony
Received 23 April 2004, accepted 11 February 2005
Associate Editor: Jesper Madsen