This is the most prestigious photography competition in the Planet. It is organised by BBC and Natural History Museum London. There are several categories and images are awarded winner, runner up, Specially Commended and Highly commended. The winning photographs are displayed in the Natural History Museum London.
The link to the photography competition website is as follows. Please go through the winning photographs of the previous years. It will teach us a thing or two.
A word of caution. The rules are very stringent. No cloning or cropping to remove distractions like branch, animal, parts of animal etc. Cloning is allowed to remove dust spots only.
Corrections are limited to colour, contrast, sharpness (minimal is advised) etc applied to the whole photograph. You are not allowed to do corrections on individual channels (R, G and B).