I haven't seen mama or her kittens since Monday night. Come Tuesday morning they were long gone. BK is still here but he's not telling me where his family is or why they left.
I walked around the neighborhood looking for possible places where mama kitty's nest might be and found two potential places that are in the alley across the street. Both are well sheltered, unheated and secured, so I can't get access to them. I'm not sure what else to do at this point than to wait and see if she comes back.