If you spend time on the camera forums, the “experts” there will complain about the “crop factor” applying to depth-of-field as well as field of view. The cruz of the complaint is to infer that you cannot get an out-of-focus background with such cameras because f/5.6 is really more like f/11.
Not everyone can afford a big, fast, lens. It’s particularly hard to find the loose change to buy a big telephoto lens. While the lesson I offer here applies to ALL cameras and ALL lenses, regardless of manufacturer OR format, it is most apparently impactful when you are shooting with telephoto lenses.
Photograph birds at eye level – use the LCD that pans and tilts if you don’t want to get on the ground. Get close to reduce DOF.