Combining ensemble models and connectivity analyses to predict wolf expected dispersal routes through a lowland corridor

Abstract

The Italian wolf (Canis lupus italicus) population has remained isolated South of the Alps for the last few thousand years. After a strong decline, the species has recolonized the Apennines and the Western Alps, while it is currently struggling to colonize the Eastern Alps. Recently, the species was detected in a lowland park connecting the Northern Apennines to the Central Alps. If the park was able to sustain a net wolf dispersal flow, this could significantly boost the connection with the Eastern Alps and the Dinaric-Balkan population. We investigated the suitability of the park as a functional ecological corridor for the wolf through the unhospitable lowland of Northern Italy. We collected wolf occurrence data in two study areas. We modeled species distribution running a separate ensemble model for each study area and then merging the output of the models to obtain an integrated suitability map. We used this map to identify corridors for the wolf adopting a factorial least-cost path and a cumulative resistant kernel approach. The connectivity models showed that only two corridors exist in the lowland areas between the Northern Apennines and the Central Alps. The Western corridor is a blind route, while the eastern corridor passes through the park and has a continuous course. However, the models also revealed a scarce resilience of corridor connectivity in the passageways between the park and the Apennines and the Prealps, which suggests that urgent management actions are necessary to ensure the future functionality of this important corridor.

En route to the North: modelling crested porcupine habitat suitability and dispersal flows across a highly anthropized area in northern Italy

“…The Po Plain is characterized by the presence of scattered natural (e.g., riparian vegetation, broad-leaved woodlands, and shrublands) and semi-natural (e.g., hedgerows and arboreal cultivations) vegetated patches, which can represent a sub-optimal habitat supporting the occurrence of many forest-dwelling mammal species (Balestrieri et al 2015(Balestrieri et al , 2016Chiatante et al 2017;Dondina et al 2019). These landscape features can also mitigate the effects of fragmentation by increasing connectivity and supporting long-range dispersal movements of individuals, as observed for many mammal species both in other geographic contexts [e.g., carnivores (Hilty and Merenlender 2004;Šálek et al 2009;Virgós 2001) and rodents (Bani et al 2018;Silva and Prince 2008)] and in the Po Plain [e.g., the hazel dormouse Muscardinus avellanarius (Dondina et al 2018a); the European badger Meles meles and the roe deer Capreolus capreolus (Dondina et al 2019); the Italian wolf Canis lupus italicus (Dondina et al 2020)]. The possibility of crossing the Po Plain by the crested porcupine would have the important consequence of leading the species towards the Prealps, an area potentially suitable for colonization (Mori et al 2021), where occurrences start to be detected.…”

“…We considered a fine spatial scale to modelling dispersal flows because habitat suitability models have proved to be a useful alternative to movement data to parameterize the landscape resistance to animal movement provided that environmental variables are calculated at a finer spatial scale compared to the scale generally used to parametrize habitat suitability for a species, i.e. the home-range scale (Ziółkowska et al 2016;Dondina et al 2020;Torretta et al 2020). Dispersers typically depend on the availability of local resources during their movements (Zeller et al 2012), while resident individuals usually have broadscale ecological requirements (Mateo Sánchez et al 2014).…”

“…The centroids of these cells were used as source locations for connectivity modelling. While in the Apennines and lowland area we retained all source locations, they were fictitiously rarefied in the Prealps (forcing a minimum distance of 10 km) to simulate a very sporadic presence of the crested porcupine in this area (Dondina et al 2020).…”

Genetic Population Structure of Wild Pigs in Southern Texas

“…Effective management requires a twofold action: definition of a target area for management and ensuring containment of the managed area. Therefore, practitioners must manage at the scale of local populations, and identify and target dispersal corridors [ 12 , 13 ]. One problem is how to define the target area when there are no obvious breaks or population boundaries and little specific knowledge of animal movements and dispersal in the management area.…”

First assessment of habitat suitability and connectivity for the golden jackal in north-eastern Italy

“…Dispersers mainly depend on the availability and use of local resources during their movements (Zeller et al 2012), while residents usually have broadscale requirements (Mateo-Sánchez et al 2013). To obtain a resistance map representing the permeability of the landscape to the golden jackal we converted the fine-scale suitability map by using an exponential decay function (Mateo-Sánchez et al 2015a, b;Dondina et al 2020). Connectivity modelling was then developed adopting a factorial least cost path (Cushman et al 2009) and a cumulative resistant kernel approach through which we calculated the least cost dispersal Gaussian kernel around each source location up to 400 km.…”