All though the looks of the owl is very scary, it is so sad that they died by eating poisoned rats by not knowing.
But you can't completely blame farmers for that. Yes it is true that owl, cat help us to get rid of unwanted animals like rat and others but the farmers also have to save there farms as they work so hard to grow and their families depends on that.
Unfortunately, for the sake of saving the harvest, farmers often do what is dangerous not only for birds, but for humans. For example, treat the fields with chemicals.