Zmienność cech fenotypowych samców sarny europejskiej (Capreolus capreolus L.) na tle gospodarowania jej populacją w północno-zachodniej Małopolsce

Abstract

The objective of the present work was to evaluate the individual quality of male European roe deer by statistical analysis of antler traits, craniometric characters, and age of hunter-harvested bucks. Those measurements enabled a reliable assessment of antler quality, changes in carcass weight with age and between hunting seasons, as well as phenotypic traits depending on habitat (percentage forest cover, geographic mesoregion). The work also aimed to assess the effectiveness of deer population management in the Cracow Region of the Polish Hunting Association and determine the potential of that population based on analysis of medal-quality roebucks harvested there over the past 10 years. The study involved data concerning roe deer in the 60 hunting districts comprising the Cracow Region for the 2008/2009-2017/2018 hunting seasons. The study material consisted of data concerning antlers from 8132 roebucks taken over that decade, such as the age of hunted roebucks, hunting district, hunt date, carcass weight, as well as the gross weight and form of antlers. A detailed evaluation of antler quality was conducted using records for 2874 individuals, including 284 medal-quality antlers, harvested in the 2014/2015-2016/2017 seasons. The trophies were evaluated in accordance with the criteria of the International Council for Game and Wildlife Conservation (CIC) and were subjected to craniometric analysis. For a comprehensive examination of roe deer quality in the Cracow Region, the study analyzed gamekeeping data, that is, annual hunting plans of the Polish Hunting Association, for the period 2008/2009-2017/2018. Several gamekeeping indicators were calculated based on those data to evaluate the effects of roe deer management and gamekeeping practices. The studied antler traits (mean beam length, antler weight and volume, CIC scores) as well as carcass weight culminated in 6-year-old individuals. In turn cra-niometric traits (skull length and width) increased significantly until the 4th year of life, while the width of pedicles increased throughout the life of the individual. The development of antlers over time was characterized by a declining rate of growth for all the analyzed parameters. The highest growth rate (more than 100%) was found between the second and third years of life in terms of antler weight and volume, as well as front tine length. Antler quality in terms of overall CIC scores was to the greatest extent affected by weight and volume. The combined contribution of these factors increased with age, and ranged from 63.9% in the youngest individuals to 74.6% in the oldest ones. Within the study area, the individual quality of roe deer varied depending on the forest cover and mesoregion. Roebucks with the lowest carcass and antler weight occurred in hunting districts with a forest cover exceeding 40%, while the highest values of those parameters were found in districts with 5% forest cover or less. In open-land areas, the share of medal-quality roebucks in the total number of harvested males was higher, at approx. 5%, as compared to 1.29% in the woodlands. The carcass and antler weight of roebucks taken in the Cracow Region was higher than that of roebucks harvested in western Poland, similar to the Kielce Region, and lower than that for the Lublin and Krosno Regions, which is in keeping with Bergmann's ecogeographical rule. Analysis of carcass weight throughout the hunting season showed that the most pronounced rutting activity was observed for individuals 6 years of age and older, which lost as much as 6% of their weight. Over the ten-year period of study, the roebucks harvested using a uniform set of selection criteria revealed an increase in mean carcass weight as well as antler weight and form, which indicates appropriate management of the roe deer population in the examined hunting region.