The cooling regime is obviously highly relative to the species. As such, I would be very careful with bar-necks as the winter low temps this species experiences in their natural habitat are relatively not low at all. I doubt if this species ever sees temps much below 70 even in the coolest winters. I know that successful reproduction has occurred with this species using a winter temp cycle of low 80’s for daytime highs and 70 for nightly lows. I don’t believe I would allow the ambient temp to ever drop below 70 at night. These are true tropicals.

As far as Sanzinia, they can tolerate lower winter temp cycling, but I don’t believe I would allow the ambient temp to ever drop below the low 60’s for a winter nightly low. The daily winter highs should probably be back up in the high 70’s to 80 if you go that low at night. I would be interested to hear from others more experienced with these species.

Kelly