DIGITALNA ARHIVA ŠUMARSKOG LISTA

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ŠUMARSKI LIST 9-10/2021 str. 27 <-- 27 --> PDF |

cohorts of 1988 and 1989; age<5 years; g: F= 6,12; p<0,05; i: F=18,01; p<0,0001). A significant difference found in the upper beam circumference between the 1993 and the 1997 cohort is present, however, only in the stags aged one and two years, not at a later age, and it was considered to be insignificant. Still, such differences generally signify the errors in the execution of breeding hunt, i.e., the average or over‐average trophy stags were eliminated from the population in “weaker” cohorts. As the age represents a categorical predictor to each variable analysed, it is impossible to apply the usual statistical methods such as a discriminant analysis or a PCA for the sake of a cohort group separation. In view of a grouping method applied, it is possible to separate various numbers of cohort groups (table 11), from four (length of tray tines and the number of tines) to eight (weight of dry antlers), depending on a variable. The cohorts do not exhibit a statistically significant difference within the same group, and in most cases the successive cohorts in a sequence belong to different groups. The exemptions are recorded in the weight of dry antlers (table 2; 1986<1988; g: F=8,37; p<0,05), circumference of coronets (table 6; 1986<1988; g: F=21,68; p<0,0001), and upper beam circumference (table 8; 1986<1988; g: F=4,60; p<0,05). Irrespective of the number of groups obtained and a variable utilized as a quality indicator, the cohorts of 1995, 1996, and 1997 may be isolated as the “superior” ones, comprising the first group of the three examined variables (weight of dry antlers, main beam lengths, length of brow tines and the upper beam circumference). In the variables of the length of tray tines, circumference of coronets, and trophy value, the 1994 cohort also comes along as a member of the first group. This cohort is interesting due to a fact that it does not exhibit a significant difference regarding the 1995 and 1997 cohorts most frequently, but it is significantly weaker than the 1996 cohort in the variables of the main beam length and upper beam circumference, so it comprises a separate Group 2 concerning these two variables. With regard to the tine number variable, the 1993 cohort (but not the 1994 one) also joins the aforementioned “superior” cohorts, whereas it also comprises the first group with the “superior” cohorts and the cohorts of 1992 and 1994 in the length of tray tines. The cohorts from the 1980s and the 1990 cohort generally comprise a sequence back, so it may be said that they pertain to the “worse cohorts,” out of which the 1986 cohort should definitely be isolated, as it has significantly lower values in most variables. The mediocre cohorts would be the ones of 1991 and 1992. The number of qualitative groups succeeded to be recognized by each individual variable varies from 5 to 8. Since the number of groups is based upon the number of established significant differences, the more differences are found, the higher a variable usability should be. Nonetheless, 8 groups were obtained through weight of dry antlers, which, in principle, are not significantly mutually different. A small number of groups obtained by the implementation of the length of tray tines and the number of tines has not succeeded in isolating the best cohorts clearly, so some mediocre cohorts (1992 and 1993) were also placed in the “best” category. Consequently, an overall |