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

Abstract

The crested porcupine (Hystrix cristata) underwent a rapid and widespread range expansion in Italy. Nowadays the species is moving towards the northernmost regions of the country and its occurrence is increasing in the highly anthropized Po Plain. Our objectives were to evaluate the suitability of the Po Plain for the species, as well as to identify dispersal corridors connecting the northern Apennines occurrence areas and the Prealps. We modelled the species home-range scale habitat suitability based on an ensemble modelling approach. Additionally, a habitat suitability prediction carried out at a finer scale was used to parametrize the landscape resistance, based on which we modelled the potential dispersal corridors for the species using a factorial least-cost path approach. The ensemble prediction estimated a potential occurrence of the crested porcupine in 27.4% of the study area. The species occurrence probability was mainly driven by the distribution of extensive cultivations, woodlands and shrublands, and water courses and by the annual mean temperature. Conversely, the movements of the species resulted mainly sustained by woodlands and shrublands and highly hindered by simple arable lands and rice paddies. The connectivity prediction showed that three main dispersal routes are likely to connect crested porcupine occurrence areas in the northern Apennines to currently unoccupied but highly suitable areas in the Prealps. The study allowed us to identify the areas in the Prealps with the highest probability to be colonized by the crested porcupine in the near future and provided important insights for the conservation of a strictly protected species in a human-dominated landscape.

Crested porcupine (Hystrix cristata) abundance estimation using Bayesian methods: first data from a highly agricultural environment in central Italy

“…Nevertheless, we believe that our estimates (0.10 ind./100 ha per area) are most closely related to the true number of individuals because of four reasons: (i) both intra-and interspecific competition, along with the low reproductive rate of the species (from one to three births per pair per year, each composed by on average one or two porcupettes) (Coppola and Felicioli 2021), may play a key role in shaping species distribution and abundance at a site; (ii) road-killing and poaching events may substantially affect the species' survival capacity; (iii) our analysis included also sub-adult individuals which notoriously disperse before settling and, hence, do not show a territorial behavior (Mori and Fattorini 2019); and (iv) each area is covered by a considerable percentage of agriculture. Therefore, because homogeneous agricultural areas are considered as non-optimal for the species (Torretta et al 2021), we believe that the carrying capacity of each area is lower than expected. However, in spite of these considerations, extensive cultivated fields may become hospitable for the species as long as they are intermixed with either natural or semi-natural vegetated areas, which in turn provide shelters and abundant food resources (Lovari et al 2013;Mori et al 2014a;Torretta et al 2021).…”

“…Therefore, because homogeneous agricultural areas are considered as non-optimal for the species (Torretta et al 2021), we believe that the carrying capacity of each area is lower than expected. However, in spite of these considerations, extensive cultivated fields may become hospitable for the species as long as they are intermixed with either natural or semi-natural vegetated areas, which in turn provide shelters and abundant food resources (Lovari et al 2013;Mori et al 2014a;Torretta et al 2021).…”

“…We then re-classified the original CLC categories into five macro-habitat categories: agricultural areas, urban areas, canopy-covered and open areas (i.e., woodlands, forests, shrublands, grasslands), water bodies, and cliffs, glaciers, and coastal areas (Table 1). Canopy-covered and open areas were considered as "suitable habitats," agricultural areas as "moderately suitable habitats," while urban areas, water bodies, and cliffs, glaciers, and coastal areas as "unsuitable habitats" (Monetti et al 2005;Lovari et al 2013;Mori et al 2014aMori et al , 2017Mori and Fattorini 2019;Torretta et al 2021).…”

“…Factors including the abandonment of rural areas favored the species expansion because of the increase of woodland habitats, particularly suitable for porcupines especially for food and denning (Monetti et al 2005;Lovari et al 2013;Mori et al 2014aMori et al , 2017Mori and Fattorini 2019). In addition, although agricultural habitats are generally avoided, extensive cultivations may provide important food resources (especially during the warmer months) (Lovari et al 2013;Mori et al 2014a), as long as they are intermixed with patches of natural or semi-natural vegetated areas (Torretta et al 2021). As a consequence, although crop damages are occasionally reported (Laurenzi et al 2016), the crested porcupine is widely considered as one of the main agricultural pests and is frequently subjected to poaching (Laurenzi et al 2016;Cerri et al 2017).…”

Morphological and Molecular Characterization of Trichuris sp. (Nematoda: Trichuridae) in Crested Porcupines (Hystrix cristata; Rodentia: Hystricidae) from Italy

“…It is the only porcupine species occurring in Europe, with a geographical distribution restricted to mainland Italy and Sicily, most probably due to its introduction from North Africa in the early Medieval period [24][25][26]. In the last 40 years, the distribution range of the crested porcupine has increased in Italy [27][28][29], mostly because of the introduction of legal protections (National Italian Law n. 968/1977, Annex II of the Bern Convention in 1979, Annex IV of the Habitat Directive 1992/43/EEC and National Italian Law n. 157/1992). This increased distribution may potentially increase the risk of parasite infections for this species.…”