Continuing from Bell’s form observations in Victoria (previous post) …
New science
After some intensive but unsystematic searching I found two relatively recent scientific publications which answered my main questions about how Bell’s form relates to the ‘normal’ goanna. It’s easier to discuss the more recent one first, so that’s what I will do.
(1) Photographic evidence
Farquhar et al (2022) had a double aim, firstly to show that iNaturalist records could assist research and secondly to use them to define (and perhaps explain) the range of Bell’s form. His results on the second point confirm common knowledge, i.e., Bell’s form is more common in drier country. He goes on to analyse, in some detail, likely environmental causes for that pattern of distribution.