My mum once asked what B. actually did and I was constructing a fairly coherent answer involving human evolution and primates and then I ran into mapping caves like the bats do and had to fall back on "anything that seems cool". His PhD is in primatology and until the dinosaurs came along human evolution and primate locomotion covered most of his work, so I can sort of see where the term came from but "anything that seems cool" pretty much covers it.