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Body mass of the free-living wild ungulates is an important index of their vitality and varies considerably among the animals in the population; these variations have numerous environmental and temporal causes. In the research we analyzed the influence of habitat structure and other environmental factors on the body mass of roe deer. The research is based on the sample of 2604 individuals of culled deer in the area of Jelovica and its periphery; with regard to the data from 33 GIS layers of environmental factors and to the dataabout sex, age, season of the year, and population density of deer and other ungulates they were assigned to quadrants sized 100 ha. Through our research we have found that the roe deer body mass is, in addition to the main factors (sex, age, season), negatively affected by population density, share of forests, small amount of precipitation, and inclination of the terrain; it is positively affected by the intensity of insloation in summer. After the check of influences of sex, age of the animal and day of the hunt we also discovered that the body mass is negatively affected by the share of pole forest and agricultural areas; they also differ with regard to individual years and hunting grounds. The listed environmental variables most probably affect energy balance and through it body weights of animals. Thereby, an important role is played by the consumption and input of energy, reflected in the quantity and quality of food, and affected by phenology, plant biomass, and vegetation structure. Telesna masa prostoživečih divjih kopitarjev je pomemben kazalnik njihove vitalnosti in se znatno variira med živalmi v populaciji, variacije pa imajo številne vzroke okoljske in časovne narave. V raziskavi smo analizirali vpliv zgradbe habitata in drugih okoljskih dejavnikov na telesne mase srnjadi. Raziskava temelji na vzorcu 2604 osebkov uplenjene srnjadi na območju Jelovicez obrobjem, ki so bili uvrščeni v kvadrante velikosti 100 ha, na podatkih 33 GIS-plasteh okoljskih dejavnikov ter na podatkih o spolu, starosti, letnem obdobju ter populacijski gostoti srnjadi in drugih kopitarjev. Z raziskavo smo ugotovili, da na telesno maso srnjadi poleg glavnih dejavnikov (spol, starost, letno obdobje) negativno vplivajo njena populacijska gostota, delež gozdov, majhna količina padavin in nagib terena, pozitivno pa jakost sončnega obsevanja poleti. Po kontroli vplivov spola, starosti živali ter dneva uplenitve smo odkrili, da na telesne mase negativno vpliva tudi delež drogovnjakov in delež kmetijskih površin, razlikujejo pa se tudi med posameznimi leti in med posameznimi lovišči. Navedene okoljske spremenljivke najverjetneje vplivajo na energijsko bilanco, s tem pa na telesne mase živali. Pri tem sta pomembna poraba in vnos energije, ki se odraža prek količine in kakovosti hrane, nanjo pa vplivajo fenologija, rastlinska biomasa in sestava vegetacije. |
