The reason why photographers may refrain from photographing animals is due to the fact that it can be dangerous to either the photographer themselves or the animals. For example, cases where photographers will get too close to wildlife (like Tigers, Lions, etc.) resulting to animal attacks. There is also the chance of disturbing wildlife and habitats when going to retrieve images. These are the main reasons why photographers may refrain from wildlife photography.
True, because your thesis statement is a summary of the whole paper. If any information has changed in your thesis statement you have to change the essay as well.