The companion volume to Bat Roosts in Trees is available to download from this page.
So, if you want a 245 page book that describes how all the PRF form and gives you summary tabulations for all the trees in which bats have been recorded, with 89 functionally meaningful tables (i.e. they have a practical purpose), an overall 187 illustrative figures, and another 20 inspiring photographs, and all absolutely free…
Then just click: BTHK 2020. Bat Tree Habitat Key – 4th Edition. AEcol, Bridgwater