The color and tones of the photo are terrific. The sharpness of the two animals is superb. I think this might have garnered higher votes if the two were interacting with the camera, but with animal subjects this can be difficult.
Interesting conundrum in this one ... ideally you would crop it so the cement wall doesn't show, so that it looks like a more natural scene. However, since they're down in a pit if you cropped out the wall (which is acting as a reference) they'd look like the shortest giraffes ever against the trees. :-)
Good shot. I like the patterns on the Giraffes repeated in the foliage behind. I wonder what it'd look like with a narrower DOF so the Giraffes popped out more against the background.
I like the balance in this shot, it definitely leads me up to the taller giraffe. They seem to be enjoying their autumn view alright. I wish they were doing something though, this theme to me is animals doing something, animal life, not just a shot of an animal looking. Overall great composition.