A composite? No. Not at all. Why would one do that? The real thing (which this is) is so much better
Also, there was no selective sharpening. Just the normal USM.
What you're seeing may well be that at 500mm the depth of field is very shallow and so the animals faces are sharper than everything else.
15 other people were there and saw and photographed the same thing, so rest assured this is all very real.