Cheers, folks!

Bob: Good ideas, I might take some of them up later on. Just when I thought I'd walk away from this image after this post!

In the meantime, here's v.5:

I took some advices given here earlier. Again, I lowered the height of the furrows, now they're not so sharp and steep, and I reduced the red in the mud layers. I fixed the bird textures a bit, could be better, I'm not keen on the white of the wing tips and tails but, they're far better than before, regardless.
I also added some overall population colour variations, after all, and added a little more green stuff than I had before. I didn't post v.4.
Probably come back to this for a fresh take another day soon, hopefully with some more of the suggestions that I like the sound of. Not sure about a scarecrow because I'm not very good at modelling but, it had already crossed my mind, if I could find a decent one.
I didn't, however, intend on lifting the POV because this started as a simple surface shader test, where I was concentrating solely on the mud. Now that I'm sick of it, though, I might just take it in a different direction, later. Five full sized iterations in a day is plenty much for me, not to mention all the smaller LQ and HQ test renders. It's about time to empty the temp directory, anyway! I like searching through those before I delete them too because I'll probably come across a few things I've forgotten about, to go back to for a fresh take, it's been a while since I emptied it...
Cheers for the repeated lookings and input, everyone!