Your rules of the lead on in the garden to stop him barking at the birds clearly aren't working...
We have only started this today, and we have changed it so that he's allowed off lead in the garden but if he barks, then he gets put onto the lead in the garden. This then shows him that if he barks, he gets put on lead. Don't know how successful this will be as we haven't tried it yet, but we'll see.
I know I've let him do these habits which is why I said I was too soft on him before, but you don't want to be too firm either as he's a really sensitive dog and you don't want to affect him. Yes, I should have finished his puppy biting stage, and now he thinks mouthing and biting is acceptable. Yes, we should have stopped the barking at birds, but we didn't know how to, it's hard work trying to find a solution to it. His recall was 100% before a few days ago, so I was really happy I taught the recall on my own, and I'm sure in a few weeks on long line, he'll get it back again.
I think he's bored too, but we don't really know what to do about this. His routine is very regular, he gets a long (was off lead) walk in the morning to the same park meeting the same dogs, then he goes out in the afternoon for a walk through the streets (this can be similar routes). The rest of the day, he's left to his own devices, which is where the barking and stuff started. Also, my nephews come round every day (near enough) which occupies Ollie but sometimes he is locked away in the kitchen. What can I do to stop this boredom?
We are thinking of castration in another month or so, because I do worry that he'll wander and chase after the scent of a bitch across roads. All the roads are busy round here, so if he left the exit to the park, he'll have a high chance of being run over. He has got more interested in dogs recently, one was a castrated male that he followed around and humped for around half an hour and he wouldn't listen to me or anything.