A bird watcher is a kind of pious predator. To see a new bird is to capture it, mataphorically, and a rare bird is a kind of trophy. A list of birds seen on a given day is also a form of prayer, a thanksgiving for being alive at a certain time and place. Posting that list online is a 21st century form of votive offering. It's unclear what deity presides.
From the New York Times. April 2013