Anthropomorphizing birds is tricky.
A bird face looks very different than a human one. Our eyes are right next to each other. Many birds have eyes on opposite sides of their heads. Think about it. A then there's the beak- sharp and stiff. A human face is flexible. A bird face is masklike. They can't smile, frown, sneer, etc... Maybe that's why people like them. They're so pretty, yet so weird... so unlike us.
I probably learned how to draw cartoon birds from the Preston Blair books.
To cartoonize a bird, the eyes get bigger, the face gets squishier and the bird gets eyebrows and cheeks- both vital to facial expressions.
Here's two ways to do the cheeks:
You can implant the cheek in the bird's bill. I call this the "beak cheek".
It's the more birdlike of the two.
The second method gives the bird the cheek that a cartoon rabbit, mouse or chipmunk has. I call it the "chip cheek." It's less realistic, but more versatile.
Now that I've written this I'm thinking three drawings about bird cheeks? Who the hell wants to read about bird cheeks!?