Canvasback Mortality from Illegal Hunting on the Upper Mississippi River

Carl E. Korschgen, Kevin P. Kenow, James M. Nissen, and John F. Wetzel

Abstract

To quantify the consequences of local hunting on illegal kill of canvasbacks (Aythya valisineria), we studied the behavior of hunters on a 646-ha area open to duck hunting (closed to canvasback hunting) on Lake Onalaska, Navigation Pool 7, Wisconsin, during the 1991 and 1992 waterfowl hunting seasons. Law enforcement officers observed 258 hunting parties for 419 hours. Of 94 hunting parties encountering canvasbacks, 41 (44%) shot at the ducks on 56 occasions, or 27% of 207 encounters observed. Based on a ratio estimator, there were 790 (95% CI = 376) attempts to shoot at canvasbacks on the Lake Onalaska study area during 1991 and 837 (95% CI = 390) during 1992. Mortality of canvasbacks, excluding crippling loss, was estimated to be 128 during 1991 and 166 during 1992. Thus, total canvasback losses may be higher than currently estimated on a flyway or national basis. This estimating technique offers a promising method for enumerating hunter take of protected and legal species.

Key words

Aythya valisineria, canvasback, hunting, illegal hunting, mortality, Upper Mississippi River, Vallisneria americana, wildcelery

This resource is based on the following source:

Korschgen, Carl E., Kevin P. Kenow, James M. Nissen, and John F. Wetzel.
     1996.  Canvasback mortality from illegal hunting on the Upper
     Mississippi River.  Wildlife Society Bulletin.  24(1):132-139.

This resource should be cited as:

Korschgen, Carl E., Kevin P. Kenow, James M. Nissen, and John F. Wetzel.
     1996.  Canvasback mortality from illegal hunting on the Upper
     Mississippi River.  Wildlife Society Bulletin.  24(1):132-139.
     Northern Prairie Wildlife Research Center Online. 
     http://www.npwrc.usgs.gov/resource/birds/canbacks/index.htm
     (Version 01SEP98).

Introduction
Study Area
Methods
- Canvasback population
- Number of hunters
- Information about hunters
- Observations by law-enforcement personnel
- Attempts by hunters to shoot canvasbacks
Results
- Canvasback population
- Hunters and hunter information
- Observations by law-enforcement personnel
- Attempts by hunters to shoot canvasbacks
Discussion
Management Implications
Acknowledgments
Literature Cited

Address for Carl E. Korschgen and Kevin P. Kenow: National Biological Service, P.O. Box 818, La Crosse, WI 54602-0818, USA. James M. Nissen: U.S. Fish and Wildlife Service, Upper Mississippi River National Wildlife and Fish Refuge, 555 Lester Avenue, Onalaska, WI 54650, USA. John F. Wetzel: Wisconsin Department of Natural Resources, 3550 Mormon Coulee Road, La Crosse, WI 54601, USA.

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Canvasback Mortality from Illegal Hunting on the Upper Mississippi River

Abstract

Key words

Table of Contents