I use the word "bad" lightly here. I just felt like using that old Clint Eastwood spaghetti western's title...it seems to fit with what I hope to share.
Bad really means = "not a particularly effective or appropriate practice".
Specifically, in my drives around the county, at all sorts of hours, I have noticed some trends. One is to be using the squawker devices on auto on a regular basis, without variation in location and times of operation. They remain located constantly at X spot in the field, and, they turn on automatically at dawn and off at dusk.
This in my judgment will eventually create conditions of habituation where birds get used to the distress cries coming from the speaker box.
Variation in both location and operation, will in my judgment, add to the grower's repellent strategies.
Secondly, I have noticed some growers keeping the squawkers on ALL night. This makes no sense. Birds know perfectly well that the sort of sounds (and presumed actions such represent) do not occur in the night, and surely ALL night long. This is so counter to what these devices were designed to do in the first place - mimic actual predator/prey encounters.
And again, as the sun begins to rise, having had the squawker running all night, and continuing with new daylight, the birds will naturally associate this as only background noise, andwill thoroughly disregard it as a threat...thus habituating.
I hope this helps.
REMEMBER: The villain is the Starling. It is not the grower.