Hi, Ulco. The birds are actually robins so, you're right on with that assumption. I edited the texture to remove the red breast and I slightly manipulated the main colours too because the TG outputs of the original texture came out with a kind of green/red tint, compared to the brown mud. The feather texture is firstly broken up a bit with a fractal in the colour function and secondly, with a 3x Perlin population variation over the population scale.
I had to omit the specular entirely because even without spec', the model looks extremely shiny and raising the bump mapping didn't help past a certain point, I have it(bump) as high as I can without looking too fake, just now, I can imagine this to be feathers, any higher, though, and it looks like bumps.
Incidentally, the eye is just part of the main body of the model, not a separate object and as such, it's just textured with the main image map, no special trickery with reflectivity or anything. Here's the
link to the original bird.
Thank you, Sir!