. The Canadian field-naturalist. 1978 RUSCH ET AL.: RUFFED GROUSE, MANITOBA 125 Table 2—Percentage of young Ruffed Grouse in bags of hunters checked near Gunton and Woodlands, Manitoba Dates Numbers of hunters checked September 18, 19, 1970 September 24, 25, 1971 September 23, 30, 1972 September 22, 29, 1973 749 1110 1097 397 Number of Ruffed Grouse bagged 895 117 38 Percentage of young grouse 62 66 66 76 plot. These movement data provide no evidence that egress from the study plot was excessive or that it exceeded ingress. But sample sizes are small, distribution of hunters is unknown, and th
. The Canadian field-naturalist. 1978 RUSCH ET AL.: RUFFED GROUSE, MANITOBA 125 Table 2—Percentage of young Ruffed Grouse in bags of hunters checked near Gunton and Woodlands, Manitoba Dates Numbers of hunters checked September 18, 19, 1970 September 24, 25, 1971 September 23, 30, 1972 September 22, 29, 1973 749 1110 1097 397 Number of Ruffed Grouse bagged 895 117 38 Percentage of young grouse 62 66 66 76 plot. These movement data provide no evidence that egress from the study plot was excessive or that it exceeded ingress. But sample sizes are small, distribution of hunters is unknown, and the possibility of different rates of egress in different years cannot be ruled out. Ratios of juveniles (<3 months of age) to adults among birds flushed on the study plot in June 1971 and 1972weresimilar(:1 and :1; chi-square = , P = ). Percentages of young among Ruffed Grouse in bags of hunters at nearby check stations were identical (66%) in 1971 and 1972 (Table 2). This is essentially the same as the weighted and unweighted 10-year mean percentages of young in hunter bags (64% and 65%, respectively, of 3922 grouse). Of the three drumming males present on the CO Q < X UJ CO Z) o CL (D Q UJ Z) MINNESOTA. \^WISCONSIN MANITOBA 1970 1971 1972 1973 YEAR Figure 1. Indices to numbers of Ruffed Grouse harvested by hunters in Manitoba, Minnesota, and Wisconsin in 1971-1973. Narcisse plot in 1972, only one was a survivor of the 100 drumming in the previous spring; the other two were young birds. Lack of data on the sex and age structure of spring populations precludes calculation of precise survival rates for other population cohorts. Maximum survival rates, calculated from population estimates of grouse in June of 1971 and 1972 and assuming that all 43 adult grouse present in June 1972 were either one year of age or older (Table 1), were for young (43 of 1291) and for adults (43 of 309). A crew of seven men intensively searched a 40- ha area of upland f
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