Holy buckets! :blink: looks like I waited a day or two too long to post in this thread. I’ve got a lot of catching up to do.
Besides seconding Malte’s suggestions on the background for the first image, I would have made the sky hazier, and kept the sun and the dead trees from the sketch in the finished picture. The characters, however, turned out great!

I love their coloring, and the nest looks pretty good as well.
You should definitely post sketches of your pictures more often.

(I’m not going to leave feedback on the ones for which you’ve already posted completed versions.

)
Pterano making a better move on Ada than D'Artagnan or Logan 5 

And an appreciated one at that.
Hmm...Looks like you're experimenting with a different beak style. Looks good on Ada.

On Pterano, though...well, it’s kind of hard to recognize him, actually.

Is Pterano supposed to be kneeling? His left leg (especially the knee) looks sort of funny. Also, Ada’s right shin, and the part of her foot that is lifted off the ground, both look very slender compared with her left shin and foot.
Legs aside, both characters are excellently drawn.

And Ptyra introducing Crash to Pterano

She looks so proud of herself
Awesome (and hilarious

) piece! Crash looks very cute, and all of the characters' expressions are fantastic! Though Pterano’s lower jaw ought to be more equal in length with his upper, and he’s missing his nostrils again.

Both flyers' legs also look overly bent, and for both of them, the leg on the side that is further away from the viewer's perspective (left for Ptyra, right for Pterano) appears longer than the opposite leg. Ptyra's left wing membrane also seems to disappear behind her leg.
A concept of Pterano and Ptyra finally finding each other after I-don't-know-how-long yet. With a simple background that is bound to change DRAMATICALLY.

Pterano's crest looks unusually long in this one. Ptyra's pupils also look to be positioned a bit too high, so her line of sight seems to be aimed slightly over Pterano's head rather than directly at his face. And again, unfortunately, there are problems with both flyers' legs. Pterano's right leg looks too long and sharply bent compared to his left, and while the outermost toe on his left foot is accurately pointed, the others are still hooflike. As for Ptyra, I noticed that her left knee overlaps her left wing membrane, yet her hand is in front of that knee.
Overall, however, Ptyra's body and arms are very well drawn, as is Pterano's hand and entire face (including beak).
I plan to have an elderly Domehead couple adopt Crash later, and this one is right after it happens

I need to fix their arms on the left side (it is the left, correct?). That's the REALLY hard part about drawing fliers :/
Aww...I love this picture!

/

I’ve got extremely stingy tear ducts, but I swear I felt my eyes getting moist looking at this one. Both characters are incredibly well drawn, to boot. Oddly enough, I don't notice anything wrong with their arms.

Their toes, admittedly, could stand to be more pointed. Also, when you color this image, I think you should have Ptyra be a slightly different shade from Pterano, so that they’re more distinct from one another.
I can come up with surprisingly little to say about the last sketch, but both characters look very good.

(I'm also curious to see how you're going to color Rosa.) One thing I would suggest changing is their toes, especially Pterano’s; they look way too rounded.