While I love to visit the zoo on warm summer days, I usually don't come home with many good pictures, and the reason why can be summed up in one word: Strollers. Anyone who's visited a museum, zoo, or other such institution with me knows that the never-ending sea of strollers is pretty high on my list of pet peeves, and on at least one occasion the shuffling mob gave me a migraine and sent me off home. There is an easy way to avoid this, however; visit in the wintertime. The above photo is of Zeff, a 14-year-old female Amur Tiger (Panthera tigris altaica), taken right around 10 AM on a cold…