Most people won’t be training small house dogs to this level and instinct is still go to be a concern having them around birds. I grew up training sled dogs and we trained them to ignore wildlife on trials. The same dogs in a different setting would act differently and even though they would ultimately obey our commands over their own instinct a couple seconds is all it takes to kill a bird.
Truthfully, most people don't train their dogs at all. Any size. My small dog was trained to just as high of a standard. And the thing is, I know for a fact that there are people who train small dogs to a high standard, because I trial with them. Yes, they are the minority, and that's disgusting. And instinct is actually not "all powerful". There's even some new-ish research out about that specific thing.
To your second comment, you are absolutely correct that dogs are HIGHLY situational! That's why you train situationally, and proof anything that you want generalized. A funny story about that, my dogs are on their BEST BEST behavior inside (because that expectation starts from day 1). They NEVER touch my plants. Wouldn't even dream of it, don't even consider the beginning of the thought. I put a house tree (citrus, I live in a cold area) outside one summer, and went outside later that same day, and found that my dog had chewed the whole thing off 6 inches above the dirt! But, she had never been taught the those rules extended outdoors. And, as far as prey drive, they GET to chase wild animals outside, because they help protect my outdoor birds (pheasants, pigeons, wild dove species, that type of thing). Predator proofing pens only works until it doesn't, sadly. But when they come inside, that is completely off the table. It DOES help that they have the opportunity to fulfill that drive, just like a pack of wolves doesn't hunt EVERY time it sees a prey animal, they wait for the right opportunity.
But that goes back to management. I really don't understand why this part of my comments keeps getting skimmed over. Think about how you potty train a puppy (with modern knowledge). You don't just see a puppy poop on the floor, yell at it, and then stick the puppy's nose in it and throw the puppy outside. The puppy learns that you REALLY don't like seeing them poop. So they go into the other room to poop, so that you don't see them poop! But, if you MANAGE them, they don't learn that pooping in the house is even an option. You have the puppy on leash, in a crate, or in an x-pen within sight, and ideally before the puppy even starts pottying (through understanding when they are likely to need to potty), but at the latest, the second it does start, you scoop puppy up and take it outside, and then you make a big fuss when it DOES potty where you want it to. But you can only do that if you are managing them, because otherwise, you wouldn't even see it happen.
My dogs are VERY high drive. So, guess what? They aren't allowed loose ANYWHERE in my house, not even one second, until they learn that bouncing off the walls from 5 feet up (and yes, that is a REAL problem, lol), is not what we do in the house (among other things). Even when they are little itty bitty things, I tend to carry my puppies much of the time outside (I can put a toy in their mouth inside). Why? Because of their drive, they are prone to grabbing onto the leash and tugging, and I don't like having my leashes destroyed, so I keep the time they are down on leash limited, because then they simply don't learn that behavior. It's a bit more complicated than that, since they obviously have the option while pottying, but there's different ways of handling it depending on the individual.
So, when you are talking about a prey animal, the very first step would be with a barrier. Obviously a cage, for most birds, but sometimes, the dog has been reinforced for it enough (self-reinforcement is a thing) that they need to be back even further, even behind another door. So you manage the environment where you CAN train withOUT the dog keying in on the bird at ALL. Not even a ear flick. So, behind whatever barriers, AND with the dog on leash, so they can't just change the environment. THAT'S how you teach a dog to ignore the birds. And MOST dogs should never get too far beyond that. My dogs are on leash if they have to walk through a room with a loose bird. I have two that MAYBE could be loose with a loose bird. The one has ZERO prey drive at all (I've tested it, because I WANTED her to have prey drive, she looks like a malinois, but is definitely not, and then my husband fell in love with her), but only if she was "stationed" on the couch WITH my husband. The other one is my retired competition dog, and she's been titled several times, and unfortunately, after an accident, she is pretty slow. But even her, I'd have her on one side of me (that's what she wants anyway, to lay on the couch and then crawl inside my skin, ad nauseum), and the bird would be elsewhere in the room on the other side of me. So, if she went after a bird, she'd have to go OVER me. And I don't take kindly to that at the best of times, lol. And honestly, why bother with that, when they can either just go upstairs or play outside?
Sorry to write a novel about this, but it really seems like people are NOT understanding the management component, or keep missing it. So I felt that it needed some explanation. It! Is! The! Most! Important! Part! Of! Keeping! Both! Predators! And! Prey! Training is the cherry on top. I hope that clears some things up. And I do know that there are still going to be people that take risks I would NEVER condone. Unfortunately, I can't stop them, all I can do is explain the basics of how I have dealt with dogs, that are higher drive than anything 99.9999% of people will ever have, how to coexist safely, and in a way that my prey animals don't have to live in fear, which is highly important to me. It's why I don't even allow sleeping on cages, or watching them. Plus, it's much easier to take a mile, if you already have that inch.
