Stanište ili životnu sredinu definiramo kao skup prirodnih resursa i uvjeta prisutnih na nekom području koji osiguravaju stabilnost populacije koja ga nastanjuje. Rogovlje porodice jeleni (Cervidae) je primjer brzorastućeg tkiva i jedinog organa sisavaca sposobnog za cjelovitu regeneraciju. To nazivamo ciklus rasta rogovlja i on je usko povezan s reprodukcijskim ciklusom, hormonalnim procesima te klimatskim i hidrološkim čimbenicima. Klimatski i hidrološki čimbenici djeluju izravno putem temperature zraka, oborine (kiša, sinjeg), pokrova na tlu (sinjeg, led), sunčanih sati (fotoperiodizam) te visinom vodostaja. Jednako tako klimatski i hidrološki čimbenici djeluju neizravno kroz vegetaciju. Ovaj rad će kroz prizmu klimatsko – hidroloških čimbenika obrazložiti razlike u vrijednosti rogovlja kod mužjaka jelena običnog. Područje istraživanja je Baranjsko podunavlje. Ritsko-močvarna staništa Dunavsko-Dravskog porječja imaju oblik pravokutnog trokuta, a nalaze se na sjeveroistočnom dijelu Republike Hrvatske, na samim granicama s Republikom Mađarskom i Republikom Srbijom. U tom jedinstvenom prirodnom području, staništu brojnih vrsta biljaka i životinja, očuvana su izvorna staništa jelena običnog (C. elaphus). Istraživanje je trajalo šest lovnih godina, od 2004/2005 do 2009/2010. Za istraživanje su se koristili podaci uzeti sa srednjedobnih i zrelih mužjaka (5 i više godina starih mužjaka). Vrijednost rogovlja se promatrala kroz sljedeće odlike jelenskog rogovlja: masa rogovlja, ukupna duljina grane, duljina paroška srednjaka i broj parožaka. Lovna 2007/2008.g. pokazala se s vrijednostima promatranih odlika signifikantno viša u odnosu na 2004/2005., 2005/2006 i 2006/2007, dok u odnosu na 2008/2009. i 2009/2010.g. promatrane vrijednosti nisu signifikantne, ali su više, što je u biološkom smislu jednako važno. S obzirom da su mjere gospodarenja bile tijekom godina istraživanja jednake, razlog je potražen u klimatsko – hidrološkim čimbenicima staništa. Iz hidroloških izvješća vidljivo je da je redovno proljetno plavljenje rijeke Dunav izostalo tijekom 2007. godine, što je tijekom ostalih godina bio slučaj. Srednja mjesečna temperatura tijekom najhladnijih mjeseci krajem 2006.g. i početkom 2007.g., nije bila uobičajeno ispod nule, već su se srednje mjesečne vrijednosti kretale od 2,9 °C do 8,4 °C (studeni, prosinac, siječanj i veljača). To su ujedno bile i maksimalne zimske temperature tijekom 10–to godišnjeg razdoblja, a i najmanji broj hladnih dana (<0,0 0C) tijekom ta četiri mjeseca (35). Količina oborina u prva tri mjeseca 2007.g. nalazila se nešto iznad prosjeka (142 l), no tijekom travnja i svibnja bila je i do tri puta manja nego tijekom ostalih godina istraživanja (45 l). Broj dana sa snijegom je tijekom najhladnijih mjeseci 2006.g. i 2007.g. (studeni, prosinac, siječanj i veljača) iznosio 2 dana s najvišom visinom sinjega od 1 cm, dok je tijekom 2007.g. u prvih pet mjeseci bilo više sunčanih sati nego u ostalim godinama istraživanja, a posebno se to odnosi na mjesec travanj kada je rast i razvoj rogovlja najintenzivniji. Na temelju navedenog, razvidno je kako su vrijednosti mjerenih parametara rogovlja bile najviše u lovnoj 2007/2008. godini radi izrazito povoljnih klimatskih i hidroloških prilika u vremenu značajnom za rast i razvoj rogovlja.Habitat is defined as a set of natural resources and conditions present in a given area that ensures the stability of the population that it inhabits. Antlers of Cervidae family are an example of fast growing tissues and the only organs of the mammals capable of complete regeneration. Each year the antlers are discarded and each year the new set of antlers are grown. This is called a cycle of antler growth and it is closely associated with the reproductive cycle, hormonal processes, climate and hydrological factors. Climatic and hydrological factors can influence directly through air temperature, precipitation (rain, snow), ground cover (rain, snow), sunlight hours (photoperiod) and hydro levels. Climatic and hydrological factors can influence indirectly through vegetation as a source of food. The aim of this paper is to link climate and hydological factors with the developement level of red deer antlers. The research area is periodically flooded parts near the rivers of Danube and Drava and it lies in the northeastern part of Republic of Croatia, on the border with Hungary and Serbia. At this unique natural areas one can find habitats for many species of plants and animals and it also represents an preserved habitat of red deer (Cervus elaphus). The study lasted for six hunting years – from 2004/2005. to 2009/2010. For this current study the data were taken from middle aged and mature stags (five and more years old). Total of 382 stags were measured. The value of antlers were observed through the following traits of red deer antlers: antler weight, total lenght of branches, lenght of tird tine and the number of tines. Hunting year 2007/2008. showed values of observed characteristics significantly higher than hunting years of 2004/2005., 2005/2006. and 2006/2007, as compared to hunting year of 2008/2009. and 2009/2010. observed values were not significantly higher but they were higer and that is in a biological sense equally important. The management measures were the same throught the years of research. Hydrological report showed that regular spring flooding of the Danube river failed in year 2007. and that was not the case during the other years of research. It would be normal that the average monthly temperature during the coldest months for this habitat was below zero but during the end of 2006. (November and December) and in the beginning of 2007. (Januar and Februar) the average temperature was from 2,9 to 8,4 °C above zero. That was the maximum temperature during the winter in 10 year period and that was winter with the least number of cold days (<0,0 °C) (35 days during these four months). Rainfall in the first three monts of 2007. were slightly above average (142 l) but during April and May the level of rain was up to three time lower in the relation to the other years of research. Number of days with snow was only two days during the coldest months of 2006. and 2007. and the height of snow cover for this two days was 1 cm. In the first five months during 2007. there were more sunshine hours than in other years of research, especially during the month of April when the growth and developement of antlers is most intense.Based on the results presented in the text above the values of measured antler traits were highest in huntig year 2007/2008. and that was because of extremely favorable climatic and hydrological conditions in a significant time for antler growth and developement. The results from this research can be a guidance for future prediction of red deer antler developement in a sence of creating management measures
