You have some amazing stuff on your Flickr, love the stoat
its not a particularly big crop and very little post processing apart from curves and shadow'highlights. It was shot around midday so that could be the answer,looks like a bit of a crop,is that so?While it looks sharp enough I am not sure what you have done in PP, as to me it looks like every shadow from the picture has been removed,almost to the point where it looks like it has been lit by flash.