Collecting data on rattlesnakes Published March 6, 2013 By Dustin Akins Kirtland AFB Natural Resources KIRTLAND AFB, N.M. -- In November 2012, a group of biologists working under a Defense Department contract mapped and investigated cave and mine features on Kirtland AFB to better understand the local bat population. At one point during the survey, biologists ventured 170 feet into a mine shaft to discover not bats, but a den of western diamondback rattlesnakes - one of four rattlesnake species that inhabit Kirtland AFB. A "den" is a place where snakes go into a state of lethargy or hibernation in winter. Some dens are occupied by many species of snake, while others may harbor just one. Recently, the Kirtland AFB Natural Resources office started to track and log the temperature in the den. For the most part, when snakes den up during the winter, the den will maintain a very cool temperature. Snakes, like all reptiles are poikilothermic -- they regulate their body temperature through behavior by moving closer to or away from heat sources. The cooler temperature slows the snake's metabolic rate; a slower metabolic rate means the snakes aren't wastefully expending energy on body functions that would normally be associated with warmer temperatures. The den discovered in the mine shaft, though, is quite warm, so the scientists are looking into the snakes' ability to survive the three to four months of winter without consuming food to maintain their body functions. To help answer that question, Kirtland AFB biologists recently placed a thermometer in the den to track the minimum and maximum temperatures, to understand exactly what the den's temperature is doing. Once biologists have tracked the temperatures, they can begin to assess how the snakes are staying alive, or why they prefer that specific mine shaft as a den site.