"Bird"--now that's a broad term. It's like saying "mammal". Yes, a lion can do it and a horse can't. An osprey might be outdone by a crow in one fictional situation, but maybe a kestrel's better than a mallard just for another. What types of birds are we talking here?
Well, I'll just ramble a little anyway.
Now, muscovy ducks, they're really cool. They have these small claws on their wings which they use to climb trees. Some other bird has it too, although its name escapes me at the moment. Maybe--just
maybe--I'd buy it if you had such a bird, but not otherwise. (I know your blacksmith was an example, but... I just can't get that to work. At all) Maybe with beak assistance. No, scratch that. It should be possible by using the beak. Just look at the parrots. Wings, no. Absolutely not. But why would they need blacksmiths, anyway? I mean, they're
birds.
I own a wide variety of birds, from quails and pheasants to budgies, cockatiels and the said ducks, and no, they've never smiled. It's just not possible. They make various noises, though--happy noises, aggressive noises, and you can generally read a lot from their body language, the way they fluff their feathers, etc. A calm bird is all puffy fluff. Muscovy ducks and cockatiels have crests they raise and lower; both hiss when aggressive/faced with a threat--a mother muscovy duck is plain savage and will even attack humans if they threaten her young or her nest.
Have you ever owned a bird? Or do you have any friends/family members/friendly neighbours who own a bird? Or a pet shop? Or just a place where you can observe wild birds? I don't mean to be rude, but you sound a little inexperienced with birds--the best thing you can do is to observe live ones, preferably the breeds you're writing about.
Then read and watch videos and documentaries and ask people. Know your stuff, so you don't mess it up. A falcon will kill his prey with his beak; contrary to popular belief, eagles and hawks do not. They hang onto their prey with their wicked talons until the prey bleeds to death.
ETA, I couldn't find what I was looking for on YouTube, but to go off a rooster. A happy one (who's found a treat) goes this light, rolling "blukk-blukk-blukk!", he goes cock-a-doodle-do to say that "I'm here, you're in my territory, I challenge you to come forth! I've got more balls than you, now attack!", and he makes this really weird half-strangled noise when he hears an unfamiliar sound. He doesn't smile, but it's easy to tell his mood from those noises.
And muscovy ducks! One glance at
this lady tells you she's one pissed bird. Notice the bulge that appears when she hisses. Her ducklings, however, are perfectly calm and safe--you can hear that from their happy chippering.
This lady makes the typical "nesting noise" near the end there; that quacking's reserved for nesting and nesting only. So if you've got a muscovy duck in your society, the other birdies can hear that she's "with child." "
WHERE ARE YOU, MOMMY?" - you can just hear the poor thing's desperate. You don't need no terrified facial expression.
Rambling, woot.