Knowing the Outdoors in the Dark

I bumped into a mystery in the forest I could not solve, and as my observations went into many nights the book was invaluable and had more information on the activities and sounds at nioght than any I have found.It's paperback format portable. Many illustrations, no photos Divided by sounds, sights, odors... Notably the author associates a "trill" call with a Saw-Whet owl...no other source has, and as I have now recorded many dozens of this trill call...and still waiting for Cornell or Game and Fish or Audubon to identify...they are all stumped...whish this guy was still around to contact as so far he is the only one that has referred to the trill....