After "Professor" Leahy's reference to a "murder of crows", I felt compelled to look up my own long lost list of these names. I could not find it, but my desktop search engine came up with this site, with a lot more than I had: www.rinkworks.com/words/collective.shtml. So, if you want to be correct with bird group terminology, or, simply better understand your fellow birders, there you are. Have fun!