The Eurasian beaver range expansion reveals uneven future trends and possible conservation issues: an European assessment

Abstract

The Eurasian beaver is a keystone species and landscape-capable ecosystem engineer, which went close to extinction until the 19th century. Recently, thanks to legal protection and reintroduction programs, the species has recolonized much of its past range. However, in some countries this process did not occur. Objectives. Our objective is to model the potential distribution of the Eurasian beaver for current and future conditions, on a continental scale, at river and sub-basin level. We focus on the protected areas of Italy and Portugal for possible reintroductions. Methods. The study area is Europe, with a subset focusing on Italy and Portugal. We produce species distribution models for current and future conditions using climate change scenarios and predicting changes in river flow, including topographic and human disturbance variables. We then deepen suitability-related issues within Italian and Portuguese protected areas. Results. We find that the Eurasian beaver current suitability is comparable to its known distribution, although some potentially-suitable spots occur in Italy (where there are two occurrences), while the Iberian Peninsula and the Balkan countries host scattered suitable spots. Future scenarios predict a general lowering of suitability in Central and Northern Europe. Portuguese protected areas generally host unsuitable territories, while the Italian ones have reported a tangled scenario, depending on the biogeographical sector. Conclusions. Our results may support the large-scale management of the beaver, both for countries already hosting this species and those planning a reintroduction. The framework used may be applied to other species, and for different topics, from biogeography to conservation.

A bibliometric literature review in beaver management: when does the beaver become a resource?

“…2022, Serva et al. 2023). Moreover, habitat suitability models are used to 1) predict beaver dam occurrences, better understand dam site characteristics, and evaluate beaver dam carrying capacity (Macfarlane et al.…”

“Oops…a Beaver Again!” Eurasian Beaver Castor fiber Recorded by Citizen-Science in New Areas of Central and Southern Italy

“…The beaver population occurring in the Volturno River corresponds to the southernmost population of this species in the world. However, this area is suitable for beaver presence [24], and it also represents the southernmost area where the species occurred in the Middle Ages [6]. In March 2023, three videos, each of them reporting a swimming beaver, were recorded along the Aterno River, in the municipality of Vittorito (province of L'Aquila, Abruzzi).…”

“…It is unlikely that the beaver occurrences in the Abruzzi (Aterno River) and Campania-Molise regions (Volturno River) derive from releases in central Italy, given that the nearest family group in the central regions is located about 150-200 km northwards, in completely disjointed river basins [24]. Therefore, despite the species being present in the Volturno Valley up to the Middle Ages [6], we suggest that the appearance of the Eurasian beaver in Abruzzi and southern Italy may be due to further unofficial release events (see [24] for a species distribution model in Italy) by wildlife enthusiasts following the example of other European countries [1,5]. No reliable evidence on the number of free-ranging beavers in Southern Italy is available yet, given that we did not find any biological samples (excrement or fur) for genetic analyses [8,9].…”

A shifting carnivore’s community: habitat modeling suggests increased overlap between the golden jackal and the Eurasian lynx in Europe

“…To achieve this result, we take advantage of the most up-to-date Ecological Niche Modeling techniques and post-modeling GIS spatial analyses. The use of Ecological Niche Models for the management of expanding species and the understanding of their dynamics has increased in recent years (De Marco et al, 2008;Jimeńez-Valverde et al, 2011;Maiorano et al, 2011;Barbet-Massin et al, 2012a;Barbet-Massin et al, 2012b;Dawe and Boutin, 2016;Iannella et al, 2019;Rodrıǵuez-Rey et al, 2019;Serva et al, 2023). Also, Ecological Niche Models can be refined through a post-modeling phase, converting them into more precise Species Distribution Models (SDMs), in a process which increases the predictive performances and allows the creation of more realistic models (Iannella et al, 2021).…”