Nature photographers shoot a lot of images and at some point they have to wade through all of them and determine which are best for the markets. With digital photography it’s so easy to shoot massive amounts of images because the equipment is fast and there is relatively no cost.
In the days of shooting with a 4×5 view cameras, setting up and composing a scene took substantial effort. Film was expensive so there was much more of a tendency to work longer on composition, wait for perfect light, and to make sure the image worked. This slow process was in many ways editing in the field. You worked longer on each image, took a fewer of them, and had a higher rate of ‘keepers.’
With digital it is easy to blast away and many of us do it. The scenery perfect or the light is fading fast, so moving around with the camera to grab a lot of images is a natural response. Get it before the lights gone! The result is a lot of digital captures that have to be edited; at least when it comes to deciding what goes on your website for sale.