The coypu invasion is already knocking on the door of the Barcelona metropolitan region

The coypu is a rodent that was introduced to Catalonia at the beginning of the 20th century, and that since the 2000s has been advancing from the east of the territory. Now, some specimens have been detected in the Congost River for the first time, and in the Tordera after a couple of decades of disappearance, as our experts in invasive species have been able to verify. This indicates that the expansion is at the gates of the metropolitan region of Barcelona and predictions indicate that it will end up entering it . Let's break down the keys to this invasion.

The coypu ( Myocastor coypus ) is an animal that resembles a beaver or a large water rat; it is native to South America and is expanding throughout Europe, since it was introduced for breeding to take advantage of its skin , starting in the second half of the 19th century. In Catalonia, escapes from these farms were documented starting in the 1970s, but a new source of coypu from France has been the key to the current invasion . They arrived in two incursions: from the Aran Valley and from Empordà; the first seems to have been slowed down by low temperatures, but in Empordà they have found a more favorable path. The key points of this success are the mild climate and easy access to food . Their preferred means of transport to move forward are rivers, which they use as a dispersal route.

"The coypu has a high fecundity, so when it reaches areas with a good enough climate and food, which it has found in Catalonia, it is unlikely that its expansion will stop ," explains Marc Riera , a researcher at CREAF. According to the expert, " this situation means that the coypu can spread along the Catalan coast, to Barcelona , and beyond; there are already some occurrences in the Valencian Country."

The CREAF invasive species research team, led by Joan Pino , coordinates a monitoring network for exotic and invasive species known as EXOCAT . It is an initiative of the Department of Ecological Transition that has been operating for several years and has allowed the collection of numerous data on invasions in the country and the provision of manuals and initiatives for their management.

Regarding the coypu, the EXOCAT databases have almost 150 observations in the last year , which are mainly spread over the province of Girona ( where an intense eradication campaign is being carried out ). There are also recent sightings of the coypu in the Congost River and in the Tordera.

Although it seems like a harmless rodent, the coypu is having a serious impact on the wetlands of all the countries where it has arrived and it is for this reason that the well-known International Union for the Conservation of Nature (IUCN) has included it in the list of the 100 most harmful exotic species in the world . Firstly, it competes for resources such as food or burrows with the native animals that live in the wetlands, and which are also suffering from a situation of high vulnerability due to climate change. Secondly, it causes impacts on the plant species in the places where it lives and in nearby crops , since it eats the base of the plant stems and digs to reach the roots.

Unfortunately, once an exotic species becomes invasive in a territory, its total eradication is almost impossible. For this reason, our experts insist that we must commit to good surveillance and control of potentially invasive species and thus prevent their arrival. And we must bear in mind that many animals have been introduced intentionally, such as the coypu itself, which continues to advance south.