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.