Effects of individual, population and environmental factors on parameters of reproductive success of female roe deer (Capreolus capreolus L.) : doctoral dissertation
Vpliv individualnih, populacijskih in okoljskih dejavnikov na izbrane parametre razmnoževalnega uspeha samic evropske srne (Capreolus capreolus L.) : doktorska disertacija

english

doktorska dela

2017

Univerza v Ljubljani, Biotehniška fakulteta
(Obvezni izvod spletne publikacije)

We studied the effects of various individual (age and body mass) and environmental factors (several factors, determining the habitat quality), and population density on selected parameters of reproductive potential of European roe deer (Capreolus capreolus L.) females. By determining the presence and counting number of corpora lutea in ovaries we determined fertility, potential litter size and potential reproductive output of roe deer females. We analysed 1894 samples (1312 of them were suitable for further statistical analyses) of female roe deer reproductive organs collected in the period 2013%2015 in 85 hunting grounds, covering whole gradient of roe deer abundance in Slovenia. The research was upgraded by the study on effects of body mass, population density and mean July temperature on reproductive success of does at the continental scale. For this, we performed the meta-analysis of data (population means), collected from 29 studies on 61 roe deer populations from 15 different European countries. Furthermore, we also determined the sex ratio of offspring, firstly based on 39 samples of uterus with developed foetuses, and secondly based on the data on 180 does culled together with their fawns in the period 2013%2015. Our results revealed a high reproductive potential of roe deer females in Slovenia: 97.6 % of females (both yearlings and adults) were fertile, potential litter size (when considering only fertile individuals) was 1.85, and potential reproductive output (when considering also nonovulating females) was 1.80. Body mass was the most important influential factor that had positive effect on reproductive performance. The (positive) effect of body mass was age-related and its effect was more pronounced in yearlings than in adults. We detected a direct effect (after excluding the effects of age and body mass) of the mean annual temperature: with higher temperatures the reproductive ability increased. Population density did not have any influence on reproductive potential of roe deer females in Slovenia; however, the negative effect was confirmed at the European level where the gradient of population density is much larger. We observed pronounced inter-annual differences in reproductive parameters of yearlings, and also the differences among different regions of Slovenia (both in yearlings and adults). Sex ratio of foetuses was 1:0.9 in favour of males and sex ratio of fawns 1:1.1 in favour of females, but we did not find any clear influence of maternal body mass on the sex ratio of their offspring.

23.05.2023