Abundance and distribution
In a study published in the journal Wiley Ecology & Evolution, the methodologies used to produce the abundance and distribution estimates released by the national wolf monitoring in peninsular Italy. Demographic monitoring of species is the basis of conservation and management strategies for natural heritage but, for animals that live in very large areas and have low population densities, such as large carnivores, collecting data in the field can be complex. In recent years, the advent of new technologies such as environmental DNA, camera traps, GPS systems, drones and non-invasive genetic investigations has increasingly made it possible to collect large quantities of georeferenced environmental and demographic data. From the statistical analysis of these data, estimates of the abundance and distribution of the species under examination are obtained.
New demographic models
Despite technological advances in recent years, estimating the demographic parameters of elusive species remains a complex task, especially when the reference scale is that of an entire nation or several neighboring nations. The article analyzes a new family of spatially explicit integrated demographic occupancy and capture-recapture (SCR) models, highlighting their benefits for estimating the distribution and abundance of large carnivores and discussing further possibilities for improvement in the future. Specifically, the analysis highlighted how the wolf has now occupied almost all of the areas suitable for its presence in peninsular Italy.
Scientific developments
In fact, approximately 75% of the areas involved in the study were used by the species for at least part of the year. The estimate of the population size for the Apennine regions was equal to 2557 individuals, with an error range between 2127 and 2884. By integrating this estimate with that obtained for the Alpine regions, an overall consistency for the wolf population was obtained on the national territory equal to 3501 individuals, with an error range between 2949 and 3945. This is the first formal estimate of the population, produced through simultaneous sampling on the entire national territory and using analysis methodologies in line with the latest scientific developments. The simulation studies then suggested that, if the estimate were repeated, at least 30% of the national territory should be subjected to non-invasive genetic sampling (source: ISPRA).
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