Very nice behaviour shot Ken! Getting both sharp with mud on their beaks tells the story of what looks to me like a pair building the nest. Won't mind to see some more room bottom and sides.
Ken - nice perch, poses and good dof to have both sharp. Like the iridesence of the back feathers on the one on the left. Agree about a little more room below.
Hi Ken, I like that both swallow's have a different pose, and that we can see they are busy at work with their beaks full of mud. Interesting curved perch, and yes to more room below. I know that would create an unusual crop, but as Ofer stated, maybe add to the sides if you have.
I always enjoy seeing more than one bird in a photo. You got an interesting pose from both of them and they are on a nice curved perch. I also miss some room at the bottom, though I am aware of the compositional challenges. Well done.