Snakes survive cold winters in part by using underground dens, the depth of which are linked to the prevailing winter temperatures.
"Snakes, meanwhile, choose to conceal themselves during the winter months in underground dens (hibernacula). The depth of these dens is directly linked to the level to which the environmental temperature usually falls at this time of year - as is the length of the snakes' period of torpor. Snakes will often congregate in great numbers at this time to help to conserve as much of their body heat as they can. They will even share their hibernacula with other poikilotherms, such as lizards, tortoises, and toads." (Shuker 2001:109)
Learn more about this functional adaptation.
- Shuker, KPN. 2001. The Hidden Powers of Animals: Uncovering the Secrets of Nature. London: Marshall Editions Ltd. 240 p.