A court in Santander sentenced the man to two years in prison as well as a fine of €118,770 for killing 24 animals with an illegal pesticide when he attempted to get rid of Iberian wolves preying on his livestock, newspaper El Diario Montañés reported on Monday.
The Valdeolea farmer, identified as JL.V.G., was also banned from hunting for four years and has lost his permit to graze his livestock on public land.
Between December 2011 and January 2012, JL.V.G. reportedly decided to set poison traps as wolves started to attack his farm more frequently. The court said he "devised and executed" a plan to get rid of the wolves by setting out meat laced with the neurotoxin and the banned pesticide aldicarb.
The court said that the farmer's plan did not take into consideration "the species that it could affect, creating an extremely serious threat to biodiversity".
Of the 24 animals that the poisoned meat killed, five were dogs, one was a cat, three were foxes and 11 were red kites, a bird considered in danger of extinction in parts of Spain.
The court sentence also pointed out that the farmer must have been aware of the toxicity of the poison because he wore nitrile gloves, commonly used in laboratories, to protect his hands.
Aldicarb is a fast-acting neurotoxin that is highly dangerous to both animals and people. In animals, it is capable of causing paralysis and even death within minutes.
The substance was widely used in Spain as a pesticide in agriculture until its partial ban in 2003 and then complete ban in 2007.
In Spain a jail sentence of two years or under is automatically suspended if it is the first offence.