UVB Light for Ball Pythons

[Malum Argenteum]

I'm not sure if you're familiar with 'Hitchens's Razor', which states "what can be asserted without evidence can be dismissed without evidence". Seems to be relevant here.

On Ferguson Zones: I'm not convinced that there's no value in this scale. I would keep in mind, though, that -- contrary to a lot of handwaving claims to the contrary -- imitating parameters that are found in wild conditions clearly isn't a reliable method for captive success. This is true at least in part because (a) captivity isn't just a scaled-down version of the wild; (b) wild specimens are not the same as captive specimens (as the latter have been acclimated to and selectively bred -- intentionally and unintentionally -- to do well in captive conditions), and (c) wild specimens die from all sorts of things that captive care aims to avoid. And at least in some cases of 'wild conditions' recommendations, there's an underlying very basic misunderstanding about how evolutionary adaptation works (the assumption is that a wild species is adapted to all the elements of its wild environment, which is incorrect).

To take one illustrative example of wild vs captive conditions, in Dav Kaufman's contentious ball python video he recorded temp and RH in two BP burrows at different locations at 95F, 80%RH in one, and 92F, 90%RH in another. We wouldn't replicate that in captivity, since we know that those extremes aren't conducive to good results.

So while it is interesting to know what sort of UVB exposure certain species might be exposed to in the wild (even if we don't know how, when, during what life stage or to what extent those species exploit that available UVB), to simply assume that captive exposure should be the same is completely unwarranted.

On one topical point: the 'immune system function' angle is an interesting rabbit hole to go down. There's a lot of human data on this connection, and it is not straightforward. It seems that in humans there's some evidence that UVB can increase systemic immune response to some things (notably, Covid). Most studies on immune response and UVB in humans show that UVB exposure detrimental if anything. We also know that in the skin, UVB is quite immunosuppressive, which is why UVB is used to treat immune disorders such as psoriasis, and is one reason it leads to cancer. There's a clear reason why human and non-human animals have both physiological and behavioral mechanisms to avoid UVB exposure, and it is not because UVB exposure is a net benefit.