ESTIMATE OF VIABILITY AND PERSISTENCE OF THE SNAKE-EYED SKINK (Ablepharus kitaibelii) ON PAPUK IN TERMS OF STOHASTIC ENVIRONMENT THROUGH CENTENNIAL TIME PERIOD

Abstract

Ivanjski rovaš (Ablepharus kitaibelli) jedan je od najmanjih vrsta guštera u Europi, a ujedno i najmanja vrsta guštera u Hrvatskoj. Rasprostranjenost vrste u Hrvatskoj ograničena je na izoliranim populacijama na planini Papuk i gradskom parku u Iloku. Podaci su prikupljani na Papuku kroz četverogodišnji vremenski period. Cilj rada bio je procijeniti vijabilnost populacije u sadašnjim uvjetima, opstojnost populacije u stohastičnom okolišu kroz stogodišnji vremenski period i utvrditi glavne čimbenike promjene trenda dinamike rasta populacije. Prema dobivenim rezultatima procjene vijabilnosti, iako je 100 %-tna vjerojatnost opstanka, ukupna dinamika rasta je negativna. Može se zaključiti da bi aktiviranje negativnih čimbenika ubrzalo negativan trend dinamike rasta i gurnulo populaciju u prijevremeno izumiranje. Istraživanje je pokazalo da unutarnji čimbenici, kao mortalitet juvenilnih jedinki, imaju veći utjecaj na opstojnost populacije od vanjskih okolišnih čimbenika, odnosno stohastičnosti sustava. Rezultati istraživanja također su pokazali da se introdukcijom vrste i poboljšanjem stanišnih uvjeta uvelike povećava opstojnost populacije.Snake-eyed skink (Ablepharus kitaibelii) is one of the smallest European lizards and also the smallest lizard species in Croatia. The distribution of species in Croatia is limited to isolated populations on the mountain Papuk and the city park in Ilok. Data were collected on Papuk through a four-year period. The main goals of this study were to evaluate the viability of the population in today's conditions, population persistence in a stochastic environment through centennial time period and to identify the main factors of change of trend dynamics of population growth. According to the results of the estimate of viability, although 100 % is the probability of survival, the overall dynamics of growth is negative. It can be concluded that the activation of negative factors could accelerate the negative trend of the dynamics of growth and pushed the population in the early extinction. Research has shown that internal factors, such as juvenile mortality, have a greater impact on the persistence of the population from external environmental factors, environmental stochasticity respectively. Study results also showed that by introducing the species and by improving habitat conditions significantly increases the population persistence