So sorry that you are going thru this!
Not finding any feathers is a really good sign (truly!) -- If the coyotes had gotten them, there'd be feathers somewhere. Chances are they are still together, and pretty confused. Since they know how to roost from their own pen, they are probably smart enough to be spending the night in trees, which will definitely help them versus the coyotes. I don't know that they would respond to calls at night -- my birds are pretty not interested in anything except sleeping after dark.
Is anyone in the area feeding lots of birds? Backyard feeders and the like? They may get drawn to a food source, or follow other birds, if they happen to see a lot of birds flying somewhere or other. Likewise, they might be hanging near a water source, or a big open tree that they decided they like.
If you haven't found a big heap of feathers, then I wouldn't totally give up hope. I had a surprisingly large heap of dove feathers in the back yard a few weeks ago -- idk whether a hawk took the dove and sat on the wall to eat it, or a neighborhood cat got it and the dogs took it from the cat, or if the dogs got it themselves. But even something as small as a dove leaves a lot of feathers heaped and blowing around. @Birdrain92 had a bird (birds?) wander back by after a really long time... what was it, Birdrain, a year?
Anyway, know that our hearts are going out to you. Hang in there.
Well, I spoke with our neighbor, their house is 300yrds through the woods and a creek,, we can not see each others house, even in winter with no leaves. She said they saw one on Easter Sunday, the day after the 2 left us. It sounded like the slightly older one with the 3ft train of feathers. She said it was up in a tree and flew down and scared their dog, walked around a little then headed off down toward the creek. It rained pretty hard Sunday night here so I doubt I'll be able to look for any tracks in the mud.
I've been outside ever evening with my peacock calls on my phone blasting over my Bluetooth speakers, not quite as load as a pea's call but enough that if they were close I would think I'd hear something back. Last night the Owls were replying to me.
Are there any other ways to try to find them, I drive around the roads several times a day but I haven't seen a bird yet. I'm looking up in trees and in fields and the front of the few houses.
I guess Pea's don't have a good homing sense like pigeons? He's in an unfamiliar area to him and I'm not sure how he'd find his was back if he wanted too.