It's a kind of tautology to point out strange things about a Strange Creatures book. This man was a journalist with a lot of practice writing exposition. It's hilarious how much honor he says journalists have. But he 1) is very satisfied that bounties killed the last wild wolves in parts of the U.S. 2) Takes UFOlists to task for not being open to every alleged sighting in history. In tandem to reading about the apparent extinction of the Tasmanian Tiger, his obsession with strange creatures sounds a bit like hunter's bloodlust.
A catalogue listing strange sightings fills the second half of the book. For its stated intentions, the book is probably more than complete in its own strange little world.