Well yes, we are talking about the beaver and not the nutria. Yes, the beaver, that cute aquatic rodent that loves to cut down tree trunks to build real dams.
But let’s do some tidying up. Since March 2021, although clues have been collected that confirm the presence of the species already in 2019, the presence of small nuclei of Eurasian beaver (Castor fiber) has been documented in at least four unconnected areas in Tuscany and Umbria , as well as sporadic reports in the Marche on the border with Tuscany and individual signs of presence in Emilia Romagna and Lazio.
The Eurasian beaver is a large rodent, strictly herbivorous, which can reach almost 40 kg in weight, perfectly adapted to semi-aquatic life. It lives in small, territorial family groups made up of 3-5 individuals that occupy stretches of river or lake of variable length. He cuts down trees, digs holes and canals, accumulates branches to form dams that help maintain the water level above the entrance to the burrows, this allows him to protect himself from predators and to facilitate the transport of heavy branches and of vegetation used as food in winter.
Although it was originally distributed throughout Europe and Asia, in the early 1900s, following an intense hunting activity that was aimed at recovering the fur, meat and oil produced by its perianal glands , the species survived with only eight small populations. In the 20th century the species largely recovered in Europe thanks to the introduction of protection regulations, reintroduction programs and its dispersal capabilities through the hydrographic network.
In the Early Middle Ages the Eurasian beaver was still widespread in Italy, particularly in the Po Valley, from where it disappeared during the 16th or early 17th century.
After four centuries of complete absence in Italy, in 2018 an individual in natural dispersion from the reintroduced Austrian population was detected in the Tarvisio area and in 2020 the species was also reported in Val Pusteria.
But then… how did the beaver get to Umbria?
It may never have become extinct, although this hypothesis is very unlikely given that where the species is present it is easily detectable by the characteristic signs, deriving from double conical gnawing, left on the trees.
The second hypothesis, equally unlikely, is that the species arrived spontaneously from other areas. Not very likely because the distance between Tuscany and Umbria and the current areas of presence in France, Switzerland, Austria, Tarvisiano and Val Pusteria is at least 400 km and in between there is no evidence of other populations.
There may have been an escape of individuals from captivity, but the presence of reports in different areas of Tuscany and Umbria would imply several escapes of animals from various facilities that held them in captivity, or a single escape with subsequent spread to different areas. All very unlikely.
The last hypothesis, the one currently most accredited by the scientific community, is that there has been an illegal release of animals in multiple areas. Theriologists, who are zoologists who deal with the study of mammals, are wondering how to manage this situation given that although the Eurasian beaver is a species strictly protected by national and international legislation, for the European Commission, there has been a precedent in Spain, nuclei originating from illegal releases are not necessarily protected, at least until they give rise to widespread and naturalized populations.
The Italian Teriological Association (ATIt) believes that the Eurasian beavers present in central Italy are probably the result of illegal introductions and that in any case a careful evaluation of the feasibility of reintroduction should be carried out in relation to its ability to produce positive and negative alterations to ecosystems.
Any further decision on the fate of this species in central Italy will however be subordinated to a large-scale monitoring activity to locate any other nuclei present and better clarify the current distribution of the Eurasian beaver.
ATIt itself indicates that in areas where the presence of beavers is confirmed, a plan for their removal must be defined as soon as possible, to be adequately communicated to the population to make them understand the need for such interventions.
Bibliography
- Mori E., Viviano A., Brustenga L., Olivetti F., Peppucci L., Pucci C., Senserini D., Sergiacomi U., Spilinga C., Roversi P.F., Mazza G. 2021. Distribution and genetic analysis of wild-living Eurasian beavers in Central Italy. Redia, Journal of Zoology 104: 209-215.
- Posizione dell’ATIt sulla presenza del Castoro eurasiatico in Italia centrale. Documento approvato dal Consiglio Direttivo dell’ATIt il 18 novembre 2021.
Translation made by an automatic tool
Cristiano Spilinga
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- The enigma of the beaver in Umbria - November 30, 2021