Office day today filing all of the investigations we have completed. One involved a male who was cautioned for killing a heron.He had witnessed it eating a newly born duckling so decided to kill the heron in order to rescue the duckling from its stomach.#bizarre pic.twitter.com/UgVh8o09je— RuralCrimeTeam™ (@NWPRuralCrime) March 26, 2018 “Strangely he actually did rescue the duckling alive from the dead heron’s stomach. But obviously he was then left with a dead heron. You couldn’t make this up!” As the expression ‘nature red in tooth and claw’ suggests there is an cruel inevitability to life and death in the animal world. So quite what a Welsh animal lover was thinking when he tried to rescue a tiny duckling which had just been eaten by a heron is open to question.More puzzling still is the fact that in order to save it from its natural fate he cut open the heron and pulled the terrified duckling from its stomach.The effect was, rather predictable, to kill the heron, although the duckling survived relatively unscathed.The elderly man was arrested by North Wales police, but later released with a caution.North Wales Police’s Rural Crime Unit described the man as “vulnerable and elderly” on Twitter, without revealing the name of the culprit or when and where it took place.Officers said it “involved a male who was cautioned for killing a heron”, adding: “He had witnessed it eating a newly born duckling so decided to kill the heron in order to rescue the duckling from its stomach. Some people responded to the Tweet by criticising the police decision to let the man off with a caution.The heron is a protected species under the Wildlife and Countryside Act 1981, with fines or prison sentences available for anyone killing or attempting to kill one.Lee Dingain, a conservationist and trustee with the Wader Quest shorebird charity, said: “Utterly ridiculous! Not too elderly to kill an apparently ‘protected’ and not to mention formidable bird. The heron is the vulnerable one! Decisions like this are a major part of the reason why wildlife crime is not taken seriously. If he had stabbed someone he would be prosecuted.”Jane Kennedy, who describes herself on Twitter as “passionate about wildlife”, added: “Clearly a protected bird has been illegally killed on this occasion, so a crime has been committed.”North Wales Police said: “These decisions are never taken lightly and a number of factors are addressed. This was a vulnerable elderly man, who confessed voluntarily to the action with no previous convictions.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.