9th International Deer Biology Congress

AUTHORS: Mia Maor, Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel; Hila Shamoon, The Steinhardt Museum of Natural History, Tel Aviv University, Israel; Amit Dolev, Science Division, Nature and Parks Authority, Jerusalem, Israel; Shirli Bar-David, Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel; David Saltz*, Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel, and Science Division, Nature and Parks Authority, Jerusalem, Israel

ABSTRACT: Population expansion models are often used in conservation planning practices. However, the long-term reliability of such models has rarely been tested. In 1996 the Nature and Parks Authority, Israel, initiated the reintroduction Persian fallow deer (Dama mesopotamica) in the Kziv reserve. Over the next 9 years 188 individuals (equal sex ratio) were released [1]. Based on the first 2.5 years of data we developed an individual-based spatially realistic population expansion model and tested its prediction against empirical data 2.5 years later [2]. We then simulated the population’s numerical growth and spatial expansion 100 years into the future based on the current landscape and based on regional development plans [3]. Now, 22 years after the reintroduction began, we re-assess the model by comparing the models projections on range expansion, direction and activity centers the 20th year projection with empirical data based on camera traps surveys conducted in the area for the past 4 years. Cameras were placed within and beyond the predicted range of expansion and in a variety of habitats including those considered in the model as preferred to those considered less desirable. We analyzed the empirical data using N-mixture models and extracted an accurate measure of the population expansion trends and compared them with the model predictions. Our results suggest that the model based on the original landscape when the model was constructed was able to accurately predict the range of expansion relative to the release site but was less successful in predicting the direction of the expansion and the location of population cores (habitat use). The model based on development plans was more successful in predicting the direction of the expansion. Using N-mixture models we could assess what other factors, other than those originally considered, such as predation risk, affected the spatial expansion patterns of the population. Spatial population expansion models for reintroduced species provide a comparative backdrop against which empirical data can be assessed, focusing on the progress of the project evaluated and identifying new factors (that either did not exist in the past or have been overlooked) that affect the current expansion of the population. In addition, our findings emphasize the importance of including future developmental plans in spatial models.