During drought it comes done to lack of food. Cooler temps, dryer conditions, and other problems all cause one important condition, lack of availablility of food. It stands to reason that if eggs hatching is timed to the 2nd month of the rainy season it is because of the mass of available food. Also mating occurs in Albigularis during the last month of brumation if I remember, so they are not completely inactive by any stretch, they are not hibernating, the males are out searching for females in burrows and trees, this info is in the book and in papers you sent me on albigs. A V.Griseus may hibernate (Closer to the description), but the rest of African varanids dont brumate unless they have to, after all if a drought goes longer than normal they stay inactive. According to the papers and the book, as well many other sources they sit in a burrow or in a tree actively alert, eyes open head exposed to see whats going on to react to food or danger, thats not hibernation, nor is what rattlesnakes do when cold weather comes around, they go underground in mass dens very alert, very aware, and active if needed to be, just a bit slower. The only time Ive ever seen a long term inactive, unresponsive, monitor in captivity was a dieing, or very very sick monitor, or one that was shipped in the middle of winter and the heat packs are dead, as soon as they warm up they are on the go. Note, water turtles dig down a few inches to expose their shell to the sun and air, there is a reason for it, when the sun warms them up and the ambient temps are not too low even in the middle of winter they come out and are active, I see this every year in many species of turtle, snake, etc. I know that books say all of them stay under until winter is over but thats not reality, are the guys writing that stuff sometimes afraid of the cold, or weather changes?