Michigan Department of Conservation
Research and Development Report No. 20
Institute for Fisheries Research Report No. 1700, 1964
Feeding Behavior of the Common Merganser in Captivity
William C. Latta and Reginald F. Sharkey
Introduction.-To evaluate the role of
the Common Merganser (Mergus merganser americanus) as a predator on trout population,
detailed knowledge of their feeding behavior is needed. Analyses of the stomach
contents of the Common Merganser from trout and salmon streams have indicated a
selectivity for the larger salmonids even though there were other more abundant
species of fish present in the streams to act as buffers (Salyer and Lagler, 1940;
Lindroth, 1955; White, 1957). This apparent selectivity has been attributed to
availability as determined by behavior of the prey species, of the buffer species, and
of the predator (Lindroth and Bergstrom, 1959; Elson, 1962; Mills, 1962). Our
observations on the feeding of Common Mergansers in captivity tend to confirm the
premise of availability. In addition, some information was gathered on the daily
ration needed by mergansers to maintain body weight.
We wish to thank H. L. Thompson for providing facilities for holding the mergansers at the Oden Hatchery. G. P. Cooper critically read the manuscript.
P. M. Earl prepared the graphs.