Duck eggs, ermine, Iowa, Muste/a frenata, M. erminea, nesting, nest predation, weasel
Ermine (Mustela erminea) and long-tailed weasel (M. frenata) predation on duck eggs was studied at Union Slough National Wildlife Refuge, Kossuth County, Iowa, 1984-85. Captive individuals of both species ate 2-4 duck eggs at a rate of 0.5-2 eggs per trial day. All eggs were moved but some were not opened. One hole, ringed with small fragments and "bite-outs'', was made in all eggs opened by captive weasels. In the field, the appearance of opened eggs, the pattern of egg loss and the amount of nest bowl disturbance were used to determine the number of nests depreciated by weasels. Egg loss at nests depredated by weasels generally occurred over several days; nest bowl disturbance was minimal and most hens did not abandon their nests until over half their eggs were taken. Of 263 upland duck nests that failed due co predation, 38 had eggs taken by weasels and 27 of the 38 failed solely because of weasels. Weasels also took eggs from at least 5 of 20 nests that lost 1-7 eggs before ≥1 remaining egg hatched. Because 12 of 13 weasels captured were ermine, most depredation of nests by weasels during the study probably was by ermine.
Journal of the Iowa Academy of Science
© Copyright 1988 by the Iowa Academy of Science, Inc.
Fleskes, Joseph P.
"Predation by Ermine and Long-tailed Weasels on Duck Eggs,"
Journal of the Iowa Academy of Science: JIAS, 95(1), 14-17.
Available at: https://scholarworks.uni.edu/jias/vol95/iss1/6