too many wild ducks

hello from Brisbane again
Ive a nephew that farms alphalfa (lucerne) for hay and has just started his 1st crop, not yet got the 1st cut. The local wild duck population have moved in and are mowing the new growth off as fast as it grows. I imagine this would be a recurring issue in nth america with the native geese. Has anyone ot some good ideas of gently moving these bird on until the crop is at least mature. These ducks are not good eating and we cant bring ourselves to shoot them either. We thought of spraying the crop with a mild solution of tabasco.
I think if we can break the habit for a couple of months this will all settle itself down
any ideas

Find someone with a Bird of Prey
That will chase them

David

Without killing the birds, I suppose you're left with the option of chasing them away. I've never had to deal with that many birds, so I don't have personal experience.

I've seen where Border Collies have been trained to chase birds. The birds initially don't leave but the continual harassment results in the birds moving on to a quieter location. Other breeds could be used as long as the dog had the temperament for the job.

I bet local kids would have fun chasing birds with their drones. But that wouldn't be a long term solution with a larger number of birds. There's a man in my area that uses a drone to harass the feral turkeys, effectively keeping them out of his garden.

I believe that big commercial farms use noise cannons. They also use traps for killing the birds since the cannons lose effectiveness over time.

If there is a neighbor who would like to harvest birds to feed his dogs, chickens, or pigs, then you may wish to invite him to hunt or set traps. Duck flocks tend to move on if they see members if the flock being "harvested".

I hope someone can come up with a good solution for you.

Oh one more thing. The big seed production companies in Hawaii use human bird chasers. People walk along paths in the fields and use a long lightweight pole (sometimes with a bit of reflective cloth on the tip) to chase off the birds. Low tech but it works to this day. I don't know if that would be cost effective in your case. But you might be able to find a young person willing to earn a bit of money as an official bird chaser.