I have heard of some pond owners using a well sighted-in .223 to frighten off comorants and blue heron by placing the round very close to the birds. On the rare occasions when they failed to miss, they noticed that the bird becomes rapidly and profoundly tranquilized. Prepared to report themselves to the proper authorities, but having faith in the powers of recovery in nature, they placed the resting bird in a secluded spot and, returning to the spot the next day, found that in every instance the bird had recovered and flown off. They repeat the process whenever they find a bird turning fish into fertilizer or, in the case of the blue heron, infecting all the fish in the pond with parasites as well. Should you decide to follow a like course of action, be prepared to report yourself and pay the fine if the birds you sedate fail to recover. Not being very accurate with a rifle, I have never attempted this solution myself.
