Physiological indices of stress:
Snakes are capable of producing stress hormones just like many animals. These can be used to make inferences about their welfare.
Corticosterone levels in blood taken from samples has been historically seen as a reliable indicator of stress is many animals including reptiles. When an animal is exposed to a stressor such as captivity stress, the HPA axis is activated resulting in the adrenal cortex producing cortisol.
There has not been a lot of research conducted on stress in captive reptiles, but some researchers have concluded that they are indeed stressed by various stressors such as exposure to cold and heat, intermittent change of environment, hierarchy with dominating males, overcrowding, and low relative humidity (Martinez Silvestre DVM A. et al., 2014). All of which cause reptiles to produce corticosterone and other hormones associated with stress in the body (Martinez Silvestre DVM A. et al., 2014).
Studies have shown garter snake corticosterone levels to increase over months where they have been kept in captivity (although these were wild caught) (Sparkman et al., 2014).
Figure credit: BrianMSweis
Enrichment:
Ways of reducing stress in captivity can come in the form of enrichment which is mostly not sufficient in many snake enclosures provided by casual owners.
One study conducted extensive experiments raising some snakes in more enriched environments (more branches for climbing, soils that were able to be manipulated and burrowed into and fed live mice). These snakes were able to solve problems faster than snakes that were not exposed to enriched environments, as well as hunted better and engaged in exploratory behaviour faster (Burghardt, G. M., 2013).
Photo by: Advait Berde
Providing a more complex environment for enrichment purposes and daily stimulation such as problem solving is likely not something the average pet owner is willing or capable of doing. Many researchers in this field agree there needs to be a paradigm shift in the pet trade that markets these creatures as simple minded and easy to maintain.
