I haven't a clue.
I think I got it from an album Robert Redford did in 1971: "The Language and Music of the Wolves". One side is all howling, and on the other side he narrates over the (organized and often complex) howls and describes the what the howls mean along with their lives and social order. My dad, the Scout Master, put it on tape and played it on a few campouts, loud and from a distance, after us kids were all in our tents. We knew what it was but it still made the hair stand up on the back of our necks
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EDIT: Nope, I got it from the book
"Never Cry Wolf" about a Canadian guy assigned by the Canadian Wildlife Service to study the wolves. He lived by himself where the wolves lived and was really the first (white) person to observe the wolves in natural habitat and dispel a bunch of myths. The chapter where he takes a day and 3 pots of tea to mark his camp's territory was fun. He marked right across one wolf's daily commute path out and back from hunting. On its way home, the wolf stopped like it hit a wall, sniffed for a bit, turned 90 degrees and followed the outline the new boundary. That detour became his new daily commute path