Mirosław Wojciech Karpiński
Characteristics of roe deer (Capreolus capreolus) populations in selected field and forest hunting grounds of the Lublin Upland based on morphometric and genetic parameters
zeszyt 371, ss. 95
Roe deer (Capreolus capreolus) is currently the most abundant representative of the deer family (Cervidae) in Europe. Most of the European roe deer populations have been increasing in size, density and geographical coverage. Analyzing the species population dynamics, we can expect that the growing trend will be continued. This raises the need for rational and precise management of roe deer populations, considering the latest knowledge of this species ecology.
The aim of the study was to determine the diversity of the field and forest roe deer populations, based on morphometric parameters and selected genetic parameters, and to develop and demonstrate the usefulness of two basic morphometric indices, calculated on the basis of selected phenotypic traits.
The material consisted of 750 animals, including 507 bucks and 243 does collected during four hunting seasons: 2005/2006, 2006/2007, 2007/2008 and 2008/2009 in Zwierzyniec Forest District (the forest roe deer ecotype) and Mircze Forest District (the field roe deer ecotype). Zoometric measurements were made on carcasses. Apart from weight, chest measurements such as depth, girth, and width at three measurement points were taken, and the trunk length was evaluated. The chest capacity index and the body longitudinal dimension index were calculated in the study. An analysis of the variation was used to perform variance analysis of specific roe deer biometric parameters variability and to determine the significance of the differences between mean values. Evaluation of the genetic parameters was based on a system of eighteen microsatellite primers and an analysis of mitochondrial cytochrome b fragment. The following genetic parameters were calculated: polymorphism information content (PIC) value, heterozygosity, distance and similarity and the number of migrants in each generation.
The results of variance analysis determined the effect of gender, hunting location and age on the body indices. There was no significant difference between the chest capacity index of the forest and field roe deer ecotypes. The capacity index was significantly higher in does than in bucks. In the forest roe deer the chest capacity index was significantly higher in does than in bucks, but no such relationship was observed for the field ecotype. The hunting location significantly affected the longitudinal body dimension, which was markedly higher in the forest roe deer. Significant correlation was found between the animal gender and age. The reduction in body longitudinal dimension index with age was greater in females than in males. It was found that the average body weight was higher in animals from field hunting grounds than in those from forest areas. Apart from the indices, the other morphometric parameters were higher in the field roe deer. Our results show a maximum difference of 1.5 kg, and the results of other studies, carried out in Poland over the last few years, indicate that the field deer carcass was heavier than the forest one, even by more than 2.5 kg. The relationship between body weight and the chest capacity index is manifested by a general tendency towards more slender and deeper chest and increasing body weight. Determining the morphometric body indices of wild ruminants is justified, considering the possibility of using them as a simple and cheap method for individual selection. Selection with respect to only one feature, for example body weight, does not guarantee achieving the intended breeding purpose.
Microsatellite DNA analysis using 18 polymorphic markers allowed us to determine 65 alleles, including separate alleles typical for the field and forest roe deer populations. PIC and heterozygosity values were similar in both populations. The results of expected and observed heterozygosity, calculated on the basis of microsatellite polymorphism, were slightly lower or corresponding to the range reported in the literature.
There was a clear difference in the value of the FIS coefficient, which was positive in the forest roe deer and negative in the field roe deer. Negative FIS in the field ecotype suggests relatively small heterozygote majority in the population, while in the forest deer population it indicates a significant advantage of homozygotes in the gene pool (inbreeding effect). This may be due to an internal structure of the population (Wahlund effect) or genetic drift. This hypothesis is confirmed by a relatively small genetic distance DR (by Reynolds). The Nm coefficient suggests that the number of migrants was approximately 1 per every generation. Genetic similarity IN between the field and forest roe deer populations was relatively high, whereas the DN genetic distance was similar to that reported in the literature. MtDNA analysis of individuals from the forest and field ecotype treated as one population, revealed the presence of 18 haplotypes. High haplotype polymorphism and low nucleotide diversity indicate a large founding group in the studied roe deer population.
Carcass weight and body proportions expressed by the chest capacity index and the longitudinal body dimension index are clearly different in the field and forest deer populations. The morphometric diversity was confirmed by differences in the genetic parameters of both microsatellite and mitochondrial DNA. The results of morphological and genetic analysis show a clear distinction between the field and forest roe deer, but also confirm the spatial proximity of those two ecotypes.