quality guidance

I find that most of the images of mine that get rejected are because of noise/grain. This usually happens because the ISO is too high, or the shutter speed is too high, or I read that even the camera can get too hot, causing the sensor to emit noise! (If you were actaully shooting this in what looks like Africa, the last point could be indeed a factor.) Most of the time, for me, it's because I'm using my phone or a cheap lens. I have an inexpensive 250mm zoom that I like to take on vacations for shots such as this, but often most of the results are not good enough for professional use because that lens is just not fast enough.

Noise can also be added quite easily in post production. This image looks like it was sharpened, especially visible around the eyes of the lion and its outline, and in the dark green leaves above it. Digital sharpening = noise.