Strange indeed. I thought from the first pic it might be what happened to my chicks last weekend- I left for 2 days and I came back to scruffy, mangy looking birds! They were molting feathers (sort of, they were growing feathers under the down) and the down was still capped onto the new feathers, making them look just awful. A little bit of preening prettied them right up.
Second pic, though, it definitely looks like something is wrong. The shaking is probably due to heat loss from loss of feathers. Couldn't say about the loss of feathers though. Hope someone else can!
