Assessing the Alpine ibex and livestock distribution in Gran Paradiso National Park (GPNP)

In the last few decades a drastic decrease of GPNP ibex population, linked with a reduction of occupied territories, was occurred. This decline is partially related to recent climate changes but causes are still not completely clear. This work aims: 1) to analyse Alpine ibex (1985-2009) and livestock (2000-2009) distribution in GPNP; 2) to assess relation between distribution pattern and ibex population trend in 2000-2009. The composition and spatial configuration of ibex and livestock occupied areas were described trough 5 landscape ecology metrics and tested using the Spearman’s rank correlation coefficient. The same statistical measure was also used to assess the relationship between distribution patterns and ibex population size. Results showed a reduction of ibex occupied territories from 4587,50 hectares in 1985 to 2331,25 ha in 2009 (r s = -0,818; P<0,001). Number of patches increased from 130 to 224 units (r s = 0,784; P<0,001). Livestock distribution didn’t show a particular trend (r s ≈0 or P>0,05). The relation between changes in ibex population trend and distribution patterns was not proven (all P>0,005). These results suggest that probably ibex distribution was influenced by different combined factors (landscape changes, climate change, and anthropic activities) and they show how landscape ecology approach may become a useful tool to understand the degree of fragmentation and connectivity of landscape, defined on species distribution.