The coipú already has someone to stop it

The war declared against the coipu or otter rat is leaning in favor of the Generalitat.

Oliver Thansan
Oliver Thansan
31 March 2024 Sunday 10:31
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The coipú already has someone to stop it

The war declared against the coipu or otter rat is leaning in favor of the Generalitat. The shock plan to control the populations of this herbivorous rodent (similar to rats and otters) is giving 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 notable that it was necessary to implement an action plan with brigades and traps to stop its expansion. The coipu is the most recent and worrying 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 abundantly in France in the fur industry, and after escaping from some farms it has become an effective colonizer in wetlands, ponds or streams. In the regions 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 operational 365 days a year to prevent its expansion. And the first results have been presented as one of the greatest successes in the fight against invasive species.

“We can say that no new colonization is taking place. Its expansion has slowed down,” says Anna Barnadas, secretary of Acció Climàtica. The implementation 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 rice has been significantly reduced.

Barnadas estimates that the population has decreased by 40% on average. "Specifically, we know that in the most agrarian conflict areas that affect biodiversity, such as natural parks, we have reported drastic decreases, and decrease values ​​of between 70% and 90%," he specifies. “For the first time we can say that in the face of an invasive exotic species we are trying to truly control the population,” says the Secretary of Climate Action. Once captured, the animals are legally euthanized.

The Government assumes that invasive species cannot be eliminated, but instead seeks to contain their expansion. In the case of the coipu, it is impossible to eradicate it due to its powerful reproduction and colonization strategy. Therefore, the objective is to continue controlling these populations and prevent damage to ecosystems and crops. But the definitive war has not ended, since the coipú specimens where they are located continue to show a “strong reproductive rhythm; We must remain very vigilant,” says Barnadas.

The implementation of this plan meant the entry into service throughout the year of two specific coypus control brigades, with three people and two all-terrain vehicles, and the support of the Rural Agents, among many other personnel and institutions involved. “In the current context of drought it is vital to be able to respond to the needs of farmers in our country. And protecting crops is one of them,” says the Secretary of Climate Action.

In addition to controlling the population, this year it has been possible to have a better cartography of the establishment of this species, which lives permanently in the regions of Alt Empordà, Baix Empordà, Garrotxa, Pla de l'Estany, the Gironès and the Jungle. Likewise, it has established demographic and health monitoring of the populations in collaboration with the IRTA and the UAB Veterinary Faculty.

The alarm over the proliferation of these animals went off in 2021 and 2022, when they caused serious damage to the rice fields of Baix Empordà and to the vegetation of several natural spaces (Aiguamolls de l'Empordà, Montgrí, Medes Islands, Banyoles ...). During 2022, 332 rodents of this species were captured in Catalonia, all in the counties of Girona.

The coipu (Myocastor coypus) is a rodent like rats, voles and dormice. Large in size and native to South America, it lives in humid areas with aquatic vegetation and grasses, and can weigh more than eight kilos.

Catalonia currently has 1,678 exotic species inventoried, of which 198 are invasive (12%). The inventory presented last year counted 630 exotic species, more than nine years ago, and of these, 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.