If there's one thing that can be said about most New York City neighborhoods, it's that they are perpetually evolving and shifting spheres of cultural and ethnic movement. Sometimes, as in the case of South Williamsburg, this means that long-lasting traditions get swept under the rug as new groups move in. Last week we went to the totally rad four-dimensional movie house/restaurant Monkeytown to see director JL Aronson's new documentary Up On The Roof, in which he explores the lives and practices of men who have kept giant coops of pigeons on rooftops for decades and even generations, raising hundreds of birds, racing them against neighboring pigeon keepers, or "chasing" them (literally directing huge flocks of pigeons as they loop across the Brooklyn sky by waving long sticks with plastic bags tied to the ends). The rooftops were, at one time, crowded with enthusiastic pigeon keepers, and some still meet in clubs to brag about their flocks or argue about the best breeds. Up On The Roof is really about a hobby that has made a bunch of guys really really happy, but it is one that will not last much longer: their coops are being removed from rooftops as their old neighborhoods get gentrified. Up on the Roof debuts at the NY International Film and Video Festival on September 22.