Northern Prairie Wildlife Research Center
Food Habits of Diving Ducks in the Great Lakes
After the Zebra Mussel Invasion
Christine M. Custer & Thomas W. Custer
Abstract: Zebra mussels (Dreissena polymorpha) invaded
the Great Lakes in the mid-1980s and quickly reached high densities. The objective
of this study was to determine current consumption of zebra mussels by waterfowl
in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater
Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A.
americana), Buffleheads (Bucephala albeola) and Common Goldeneyes
(B. clangula) were collected in western Lake Erie and in Lake St. Clair
between fall and spring, 1992-1993 to determine food habits. All 10 Redheads,
97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks
contained one or more zebra mussels in their upper gastrointestinal tracts.
The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher
in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels, (aggregate
percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads
(23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed
on larger zebra mussels (
= 10.7
± 0.66 mm SE) than did Lesser Scaups from Lake St. Clair (
= 4.4 ± 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake
Erie consumed zebra mussels of similar size.
This resource is based on the following source (Northern Prairie Publication
0951):
Custer, Christine M., and Thomas W. Custer. 1996. Food habits of diving ducks
in the Great Lakes after the zebra mussel invasion. J. Field Ornithology
67(1):86-99.
This resource should be cited as:
Custer, Christine M., and Thomas W. Custer. 1996. Food habits of diving ducks
in the Great Lakes after the zebra mussel invasion. J. Field Ornithology
67(1):86-99. Jamestown, ND: Northern Prairie Wildlife Research Center
Online. http://www.npwrc.usgs.gov/resource/birds/divduck/index.htm
(Version 31JAN2002).
Table of Contents
Tables and Figures
- Table 1 -- Frequency of occurrence and
aggregate percent of food in the upper gastrointestinal tract of five species
of diving ducks.
- Table 2 -- Size of zebra mussels consumed
by six species of diving ducks.
- Figure 1 -- Three general locations where
six species of diving ducks were collected.
- Figure 2 -- Size distribution of zebra
mussels from the upper gastrointestinal tracts of Lesser Scaups and Buffleheads.
Christine M. Custer and Thomas W. Custer, National
Biological Service, Northern Prairie Science Center, P.O. Box 818, La Crosse,
Wisconsin 54602 USA
Current Address: National Biological Service, Upper Mississippi Science
Center, P.O. Box 818, La Crosse, Wisconsin 54602 USA
Downloading Instructions
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divduck.zip
( 52K) -- Food Habits of Diving Ducks in the Great Lakes After the
Zebra Mussel Invasion
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