Habitat suitability and population viability analysis for potential red deer reintroduction in the Kopaonik region of Serbia

Abstract

Context: Recently, red deer populations have dramatically declined in Serbia. South of the Danube and Sava rivers, their populations went extinct locally due to illegal hunting and habitat degradation. In the whole of western, southwestern and southern Serbia available data suggest a general absence of established free-ranging populations even though this region is formally within the species’ range. Aims: Given the established priorities for artiodactyls, proposed by the relevant state management authorities, we assessed the red deer reintroduction potential of the wider Kopaonik region (995 km2). We evaluated the habitat suitability of an area where red deer are only sporadically present and established quantitative parameters and guidelines using a spatially explicit demographic analysis for the reintroduction of viable and persistent red deer populations as a free ranging species in the region. Methods: A total of four HS (habitat suitability) models were created using 21 eco-geographic variables scored for suitability, based on the species’ ecology. Optimal habitat patches were identified and linked to a demographic model derived from consensually accepted management parameters. This model was iterated for all the HS scenarios with a detailed protocol of initial conditions over a time span of 15 full generations, under different regimes of demographic and environmental stochasticity. Key results: Two suitable demes with distinctly patchy structures and no inter-deme and very low intra-deme dispersion were identified. Predicted effective capacities (best case scenario) were around 220 individuals (≈1 individual per 5 km2). Successful reintroductions (extinction risk < 10%, medium stochasticity) were predicted with MVP’s between 14 and 20 individuals and initial sex-ratios of 3:1 (prereproductive females: prereproductive males) reintroduced in three consecutive reproductive pulses (e.g. 3 years, 6 individuals per year of which 4 prereproductive females). Conclusion: Our results showed that this area has a low to moderate reintroduction potential for red deer. Habitat variables were the most important HS determinants. Implications: This proposal of a framework of parameters and management procedures for successful reintroductions based on quantitative assessment of HS and PVA will be a useful guideline for the managing authorities