The war declared against the coypu or otter rat is being decided in favor of the Generalitat. The shock plan to control the populations of this herbivorous rodent (similar to the rat and the otter) is yielding good results, according to the Department of Climate Action. The damage caused by this animal to crops in the regions of Girona has been so remarkable that it has been necessary to launch an action plan with brigades and traps to stop its expansion. The coypu is the most recent and worrisome invasive exotic species in Catalonia.
The otter rat was introduced from France 14 years ago and has spread rapidly in the Girona regions. It was used a lot in France in the leather industry and after escaping from some farms it has become an effective colonizer in marshes, ponds or streams. In the counties of Girona, it has caused significant damage to rice crops, among other impacts.
To deal with it, last year the Department of Climate Action created a specific brigade operating 365 days a year to prevent its expansion. And the first results have been presented as one of the biggest successes in the fight against invasive species.
"We can say that there is no new colonization. The expansion has slowed down", says Anna Barnadas, secretary of Climate Action. The launch of this plan in January 2023 has made it possible to capture 1,548 specimens - 516% more than the previous year -, so that the damage it has caused to crops such as those of rice
Barnadas estimates that the population has decreased by 40% on average. "Specifically, we know that in the areas with the most agricultural conflicts and affecting biodiversity, such as natural parks, we have been reported drastic decreases, and values of decrease between 70% and 90%", he specified . "For the first time we can say that in the face of an invasive exotic species we are really trying to control the population", says the secretary of Climate Action. Once captured, the animals are subjected to legal euthanasia.
The Government assumes that invasive species cannot be eliminated, but what it aims to do is contain their expansion. In the case of the coypu it is impossible to eradicate it due to its powerful reproduction and colonization strategy. Therefore, the objective is to continue to control these populations and prevent damage to ecosystems and crops. But the definitive war is not over, since the coypu specimens where they are located continue to show a “strong reproductive rhythm; we must continue to be very vigilant", says Barnadas.
The implementation of this plan has meant the entry into service throughout the year of two specific coipú control brigades, with three people and two all-terrain vehicles, and the support of the Rural Agents, among many other effective and institutions involved. "In the current context of drought, it is vital to be able to respond to the needs of our country's farmers. And protecting the crops is one of them", points out the secretary of Climate Action.
In addition to controlling the population, during this year it was possible to have a better mapping of the implantation of this species, which lives permanently in the regions of Alt Empordà, Baix Empordà, Garrotxa , the Plan de l'Estany, the Gironès and the Selva. Likewise, demographic and health monitoring of the populations has been established in collaboration with the IRTA and the Faculty of Veterinary Medicine (UAB).
The alarm over the proliferation of these animals increased in 2021 and 2022, when they caused serious damage to the rice fields of Baix Empordà and to the vegetation of several natural areas (Aiguamolls de l'Empordà, Montgrí, Illes Medes, Banjoles...). During 2022, 332 rodents of this species were captured in Catalonia, all in the counties of Girona.
The coypu (Myocastor) is a rodent, like rats, moles and dormouses. Large in size and originally from South America, it lives in wet areas with aquatic vegetation and pastures and can weigh more than eight kilos.
Catalonia currently has an inventory of 1,678 exotic species, of which 198 are invasive (12%). The inventory presented last year counted 630 more exotic species than nine years ago, and of these species, 293 (46%) are new introductions (the rest is due to better knowledge). It is estimated that an average of 30 exotic species enter each year, according to Joan Pino, director of Creaf.
