Flock Behavior and Vulnerability to Hunting of Canada Geese Nesting at Crex Meadows, Wisconsin

Abstract

Fall movement and survival of 64 Canada goose (Branta canadensis) families within a flock re-established in a 579-km2 area closed to Canada goose hunting were studied in 1972 and 1973. Distinct groups of families (subflocks) formed from 5 different brood-rearing areas. On attaining flight, families in different subflocks first fed in fields closest to the marshes from which they fledged. Later, more distant fields were used, but subflocks continued to feed separately. Geese roosted in marshes nearest their feeding sites during the entire period. Hunting pressure caused families feeding outside the refuge area to change fields, but subflock composition and roosting locations were unchanged. Shallow marsh freezeup altered subflock composition, distribution of feeding geese, and roosting locations. Geese in subflocks feeding most often in the refuge were least vulnerable to hunting, and appeared to have the lowest local mortality. Two subflocks also had different wintering areas. Geese in a subflock migrating and wintering east of the Mississippi River were reported shot more often than those to the west. These results demonstrate the need to understand subflock behavior before assessing survival in local populations. J. WILDL. MANAGE. 45(4):830-841 Restoration of nesting Canada geese where they were eliminated because of habitat loss and overharvest has become common, and many reestablishments have been reported (Brakhage 1965, Dill and Lee 1970, Cooper 1978). Although the welfare of these geese depends on effective management throughout the year, many local goose populations are limited by local hunting (Sherwood 1968:82-84). Understanding fall behavior of local geese in relation to habitat and refuge needs and hunting season vulnerability is essential for their optimum management. The flock behavior of giant Canada geese (B. c. maxima) nesting on the Crex Meadows Wildlife Management Area was investigated in autumn 1972 and 1973 and in spring 1974. Objectives were to examine: (1) impact of fall hunting seasons and marsh freeze-up on the feeding and roosting patterns of resident pairs and their young of the year, (2) relationship of flock behavior to local hunting vulnerability, and (3) relationships between flock behavior and migration routes, wintering areas, and nonlocal mortality. W. H. Marshall and J. A. Cooper made suggestions during the study and reviewed the manuscript, and N. R. Stone, J. O. Evrard, and other employees of the Wisconsin Department of Natural Resources provided valuable assistance in the field. University of Minnesota graduate students, A. H. Grewe, and students from St. Cloud University helped capture the geese banded in this study. D. Heisey helped with the statistical treatments, and V. Hellquist typed numerous drafts of the manuscript. Financial support was provided by a National Defense Education Assistantship, the Malvin E. and Josephine D. Herz Foundation, Dayton's Natural History Fund, and the Department of Entomology, Fisheries, and Wildlife, University of Minnesota. The Malvin E. and Josephine D. Herz Foundation also provided funds for publication of the study results. Present address: Minnesota Department of Natural Resources, Wetland Wildlife Populations and Research Group, 102 23rd Street, Bemidji, MN 56601. 830 J. Wildl. Manage. 45(4):1981 This content downloaded from 207.46.13.184 on Fri, 29 Jul 2016 04:30:44 UTC All use subject to http://about.jstor.org/terms CANADA GEESE AT CREX MEADOWS * Zicus 831