I myself have never gone too far out of my way to ensure that the digestive tracts of my Crotaphytus are completely empty prior to brumation. One reason for this is that I basically allow the lizards to set their own brumation schedules. What I invariably see with most of my healthy captive collareds in late summer/early fall is, initially, a gradual but consistent reduction in the length of their daily activity. This generally coincides with a reduction in feeding (of the lizard's choice), which can range from very slight to extreme. During this time I make very minor, if any, adjustments to the lighting/heat photoperiod in the enclosures. Brumation begins "officially" for one of my lizards when it decides to enclose itself in one of the hidespots, sealing the entrance, and remain there indefinitely. Of course, getting all the lizards in the same enclosure to set their "brumation clocks" for roughly the same time is a virtual impossibility. To help facilitate this, I will sometimes "coax" reluctant cagemates to seek shelter for the winter by shutting off the lights early for several days in a row. Using large enclosures and providing multiple hidespots definitely helps in this regard. By the way, I would NOT recommend allowing weak, underweight, or injured collared lizards to brumate on their own, or at all, until regaining strength and building up noticeable "fat" reserves. As for the food issue, I can't recall ever losing one of my collared lizards during or post-brumation as a result of undigested or partially digested matter in their systems. I believe I have read/heard somewhere that complete emptying of the gastric/digestive tract prior to a brumation period is perhaps of more vital importance to herbivorous lizards than it is for some of the meat-eaters...has anyone else heard mention of this?
Brock
