E.  Raichev

Abstract. Being a protected species in the middle of the last century with rather limited distribution in our country, the jackal has become a widely spread species. The aim of the study was to investigate the effect of shooting on the jackal population and to reveal how its demographic structure changes, specimens from which age groups are taken out and how the gender ratio changes with age The study material comprises 210 jackal skulls shot during 4 autumn-winter hunting seasons from 2006 to 2010 in the area of Sarnena Sredna gora mountain. To determine the animals’ age year rings in the dentine have been observed by a stereoscope measuring the level of tearing upper incisors and observing the closing of basal skull synchondroses. The simultaneous use of the three methods facilitates the more precise determination of age and assigning samples to 4 age groups. Of all animals shot during the four hunting seasons 67,5 % are young ones, aged up to 1 year. The gender ratio in these groups is 2,28/1 in favour of male animals. The ratio in the two-year-old jackal population is 1,25/1 in favour of the female ones, i.e. restoration of the normal gender ratio is observed typical of most carnivorous mammals in sexual maturity. As a result of the hunting pressure only 1/ of the animals in еach age group survive by the following hunting season. The demographic structure of the jackal population in 3 Sarnena Sredna Gora mountain is strongly influenced by hunting, turnover is increased, but the effect of shooting is not enough to reduce the overall number. Jackal population is restored each year by compensation mechanisms such as migration, immigration, enhanced reproduction.