Impact of climatic factors to the percentage of young in the population of brown hare (Lepus Europaeus P.) in the Bačka district

Abstract

Climatic factors, especially temperature and precipitations, greatly affect the dynamics of the hare number and population. Climatic factors directly affect the physiological and reproductive processes of both individuals and entire populations, or indirectly, through the availability of food, competition with other species, predators and other. The age structure of the hare population at the end of the period of reproduction is an important indicator of the population growth that is used for planning the level of explotation of the hare population (hunting). The rational use of the hare's population is one of the most important protection procedures and it should be well monitored and controlled by the hunting professionals. We used the average monthly temperature and the sum of monthly precipitations in the hare reproductive period (March-September) during ten years (2000 - 2009), together with the percent of young in the hare population, on the territory of Bačka, for multiple regression (stepwise) analysis. Results of the regression analysis show an association between the percentage of young hares and the influence of climatic factors. The average temperature and sum of precipitation in June, are the strongest predictor of the percent of young in the hare's population in Bačka. According to the coefficient of determination (R2=0.50) climatic parameters account for 50% of variance in the percentage of young hares in Bačka. The regression correlation coefficient of all factors was R=0.70, which is on the border line between medium and high correlation.

Klimatski faktori, pre svega temperatura i količina padavina, utiču u velikoj meri na brojnost i dinamiku populacije zeca. Oni utiču direktno na fiziološke i reprodukcione procese kako jedinke tako i cele populacije, ili indirektno, preko dostupnosti hrane, konkurencije sa drugim vrstama, predatora i dr. Starosna struktura zečije populacije na kraju perioda razmnožavanja je važan pokazatelj prirasta koji se koristi pri planiranju stepena korišćenja zeca u lovištima. Racionalno korišćenje populacija i mikropupulacija zeca je jedan od najzanačajnijih oblika zaštite zeca i trebao bi da bude u potpunosti pod kontrolom korisnika lovišta. Multiplom regresionom analizom prosečnih mesečnih temperaturnih vrednosti i sume mesečnih padavina za reprodukcioni period (mart-septembar) od 2000. do 2009. godine na teritoriji Bačke, izračunati su regresioni koeficijenti za prosečne temperaturne vrednosti, odnosno sume mesečnih padavina. Rezultate regresione analize povezanosti procenta mladih zečeva i uticaja klimatskih faktora na području Bačke ukazuju da su prosečne temperature i padavine u junu, najjači prediktor. Prema koeficijentu determinacije (R2=0,50) klimatski parametri objaš njavaju 50% varijanse procenta mladih zečeva na području Bačke. Regeresioni koeficijent korelacije svih faktora zajedno iznosio je R=0,70, što je na granici srednje i jake povezanosti.