Sorry, Cooler. According to An Exaltation of Larks, it is "a dropping of pigeons". Pigeons do drop in a group, so I can accept that. "A gatling of woodpeckers", "a swoop of swallows" and "a squabble of seagulls" are all fine terms of venery. "A chain of bobolinks" was somebody's failed attempt at cleverness. "A parade of penguins" and "a jubilee of eagles" are almost as great as the phrase used for the book's title. Carolly