Pavlov responses require multiple repeats, and consequences have to be immediate or nearly so.
How about all the mornings where the owners didn't feed as many treats due to being distracted, or gone? Is that duck walking around with 20 different things in its little brain that it shouldn't do to get more in order to get more treats?
I sincerely doubt a duck is going to make the link between different behavior in humans, and a specific thing that it did earlier. How would the duck know that it was specifically killing another duck that was the issue, and not, say, being loud, or a car making specific noises?
If you see a duck attack another duck, and you run up, grab the attacker, and throw it, and repeat every time it attacks, that duck is pretty quickly going to learn not to attack. If you see a duck attack another duck, wait 2 hours, and then run up and throw it, you're going to have a very anxious duck that has no idea what's going on.
A semi-related misconception is the idea that, if your dog pees in the house, you should rub the dog's nose in the puddle. This won't teach your dog not to pee in the house, because the dog doesn't understand that the act is the problem. If the dog learns anything other than "sometimes the human grabs me and shoves me around", it's going to be that it should hide the puddles, because hiding the puddles means that doesn't happen.
That's why animal trainers use clickers or similar signals, to bridge the gap between the animal performing a desired behavior and the animal getting a treat. For firm associations to happen, consequences need to be as close to immediate as possible.
And, again, how does a duck know what looks innocent to a human?
We have the same opinion. Ducks can learn.
'and, again, how does a duck know what looks innocent to a human?' You gave the asnwer yourself.
"Pavlov responses require multiple repeats"
The ducks has many morning that are repeated the same. They are different whe she killed a duck.
She learned by now what scary or not-scary behaviour from humans is. They are group-animals. And prey-animals. Very sensitive to behaviour from other species that might mean that they are in danger.
Mornings were she killed a ducks we come off more as an thread to her. We talk louder, make bigger gestures, make harsher sounds. We come off more threatening.
Ducks, dogs, humans; what do we do when someone acts like a thread but you don't understand why? We become humble and innocent and pleasing. We try to show as much as we can that we are not a thread in the hope they stop threathening us.
A duck can do that too. 'act innocent'. Does she act innocent because she knows that the bible says that you should not kill others? No. Or her parents told her that? No. But she knows killing other duck = humans acting scary/different/less food. There is a brain in there. 360 same mornings with relaxed humans; 5 scary humans ones that are all also 5 nights that she had some duckfight. She cán connect that.
Just like they can connect that we kick them out when we notice them being inside robbing the catfood; and being more silent will result in us less noticing that they are doing that.
I don't even understand what you want to have a discussion with me about anymore. We seem to be on the same page. And if I am mistaken in that maybe we should end it with agreeing to disagree. Maybe my ducks can and your ducks don't. No clue. Not all ducks, just like humans, are the same. There is probably a big chance that my ducks are more prone to adapt on/to human behaviour because we raise them in our house when young and they are not duck-raised. Creating a situation that it is more important for them to try to make something of our weird human behaviours. Or maybe we have by accident just some smart ones. We also had dumb ones. Some flew into a window once and never did it again, for some we had to put stickers on the windows because they don't learn so fast 'flying into window means pain' and keep doing it. Who knows. Probably how our ducks are raised is massivly different because it's not the same situation. Not the same environment, weather, plants, food, available humans and how they act, etc.
My ducks recently were introduced for the first time to children. Two children. The two children loved playing 'chase the duck'. If these two children were in their life daily from the beginning; they probably had different behaviour. They might be more scared of children because said 'chasing duck' games or less stressed out because they are used to these games. Who knows.
But a discussion about what ducks can do or not do is a bit pointless when we do not have the same test-subjects.
Most likely a weasel or mink members of the same family. I'd make sure your chickens are safe now because it will be after them soon. I am not familiar with the best traps but go to the predator pests forum on here and I am sure you'll get good advise.
