you are always betting erring on the side of too little than too much when it comes to burms (w/in good reason). Young burms will do just fine one 1-2 appropriately sized rodents every two weeks. Young adults (1-2 years of age) can be fed a similar schedule but larger prey and I will usually fast them at certain intervals for 2-3 weeks during this optimal feeding schedule. Once burms reach mature adulthood, particularly males, you can certainly cut back to 1 rabbit every 3-4 weeks. Sometimes it is hard to give "rules of feeding" because every burm is slightly different. Some need more calories while others don't need as much. I look for subtle things like behavior (active, alert followed by periods of rest), muscle tone, alertness, etc when defining optimal health. What I don't want is a snake that just coils in one area for prolonged periods of time; listlessness can be an indicator of several problems; obesity being one of them.
Rob Carmichael