Analysis of trophy parameters in Fallow deer (Dama dama) in Hungary, 1998-2016

Absztrakt

The assessment of the trophy quality in Fallow deer (Dama dama) is often based on the measured values of the individuals with the largest antlers. However, there is little knowledge about the reliability and representativity of this approach.

In our study, we analysed the trend of the annual number of evaluated trophies between 1998 and 2016, the age distribution of the harvested bucks, and the temporal variation in the values of trophy weight and antler length during the study period on the population level and in the case of the best quality antlers. The data were examined in 3 estimated age classes (young: up to 4 yrs, middle-aged: 5-9 yrs, old: from 10 yrs). The groups (year × age class) were characterized by the median, while the largest values were picked in each group by selecting the lowest value among the individuals belonging to the upper 1%, 5% and 10% of the sample size.

The annual number of the presented trophies increased from 894 to 3,795 with an exponential trend. The proportion of the age classes changed significantly. The proportion of the young bucks increased by 10.2%, while the proportion of the middle-aged individuals decreased by 9.9%.

The median of the weight showed no trend in the complete dataset. In the young age class, it increased until 2006, then decreased until 2016. In case of the middle-aged and old individuals, the median and the strongest values at each threshold also increased. The median of the complete dataset, as well as the middle-aged and old bucks, stagnated in the case of antler length. It showed an 8.5 cm decrease between 2007 and 2016 in the young age class. In general, the difference between the group median and the largest values showed the highest variability in case of the 1% threshold. We found a strong correlation between the group median and the strongest values only in two cases (Top 10% and 5% threshold, trophy weight of middle-aged bucks).

Our results suggest that in Fallow deer, the assessment of the trophy quality based on only the largest antlers may be misleading in several cases, especially in the young age class or if the complete dataset is treated as one group. However, the trend of the largest trophy weight in the middle-aged and old age classes may refer to the trend of the median in the relevant groups.