The London area has had too many crows. Farming provides a food source that is not natural and has the population increase to way more then should be present. The increase of one animal due to people creates a problem for other animals. Crows raid the nests of other birds so now other bird numbers are down.
the natural environment of southern Ontario is lost forever. People have given advantage to some species. Those are now a problem.
either allow management by people or you will have to pay for management. That is your only choice.