Sorry, didn't mean to be cheeky!
I believe that the comment was in regards to the swarms of crows which swoop down on CR. At DL, they would do this on the trees in the hub at dusk, and CM's would dash around banging garbage can lids together to try and chase them away (don't know if that still happens!)
On a side note, I learned a few years ago that crows always nest at night in the same spot as a group, and every morning and evening fly together on the same path to and from this spot, much like commuting to work. Then they disperse for the day to do their work, and return to the commute in the evening. Sounds like CR may be a resting place for them, or perhaps Discovery Island, with CR being under the path of their daily commute.
Hope that helps!!
Did you know that a group of crows is called a "murder of crows"?
Thanks for the reply though. Sometimes you never know if something is in literal connotation or an analogy 
