Everyone does this. When I go on photo outings with other photographers, this seems to be the major draw for them. Its fun, but not my main joy in photography. Its hard to get something “frame worthy” in this genre of photography (at least for me). Its also about the most expensive area in terms of gear. BIG & FAST glass. It use a lot of my “long” 70-200mm f/2.8 lens for this work, with a 2x teleconverter, mounted on my crop sensor D7000, really pushing the limits as far as telephoto. I really won’t spring for, or want to travel with those huge lenses.