One of the most controversial effect of golden jackal on native species is predation of juveniles, i.e. fawns of European roe deer (Capreolus capreolus), and up-following consequences on the increment rate of the species. However, for understanding a potential influence we must have science-based knowledge on reproductive ability and its variability in the target species. Therefore, we analysed effects of females body mass and age on reproductive capacity of roe deer in a large sample set of 1312 females (305 yearlings and 1007 adults), hunted throughout Slovenia. Body mass positively affected probability of ovulation and potential litter size (number of corpora lutea), although its effect was more pronounced in yearlings than in adults. Between age groups, we found clear differences in responses of both reproductive parameters to body mass which influences primarily reproductive performance of younger, and in particular, lighter individuals: at the same body mass yearlings would at average have smaller litters than adults, and at lower body mass also young to middle-aged adults would have smaller litters than old ones. In addition, while yearlings have to reach a critical threshold body mass to attain reproductive maturity, adult females are fertile (produce ova) even at low body mass. However, at higher body mass also younger individuals shift their efforts into the reproduction, and after reaching an age-specific threshold the body mass does not have any further effects on the reproductive output of roe deer females. Increased reproductive capacity at more advanced age, combined with declining body mass suggests that old does allocate more of their resources in reproduction than in body condition. Besides scientific importance of this study (publication A’), findings were very interesting also for general public (several interviews in main Slovene media after the publication in spring 2017), and were also presented as a full-page article in the Delo’s appendix Science (20 April 2017; Cobiss 4758438).
COBISS.SI-ID: 4728742