Investigating Welfare Metrics for Snakes at the Saint Louis Zoo

Abstract

Modern herpetoculture has seen a rise in welfare-related habitat modifications, although ethologically-informed enclosure design and evidence-based husbandry are lacking. The diversity that exists within snakes complicates standardizing snake welfare assessment tools and evaluation techniques. Utilizing behavioral indicators in conjunction with physiological measures, such as fecal glucocorticoid metabolite concentrations, could aid in the validation of evidence-based metrics for evaluating snake welfare. We increased habitat cleaning, to identify behavioral or physiological indicators that might indicate heightened arousal in snakes as a response to the disturbance. While glucocorticoid metabolite concentrations increased significantly during a period of increased disturbance, this increase was not associated with a significant increase in tongue-flicking, a behavior previously associated with arousal in snakes. Locomotion behavior and the proportion of time spent exposed were also not affected by more frequent habitat cleaning. These results demonstrate the need to further investigate the behavioral and physiological responses of snakes to different aspects of animal care at a species and individual level. They also highlight the need to collect baseline behavioral and physiological data for animals, in order to make meaningful comparisons when evaluating changes in animal care.

Environmental temperature influences ophidiomycosis progression and survival in experimentally challenged prairie rattlesnakes (Crotalus viridis)

“…However, the 20°C group spending more time in the hidebox may be masking behavioral changes the inoculated snakes would be more likely to exhibit in a warmer environment. Exploring the nuances of behavioral change in response to disease in reptiles has always posed a challenge for many reasons including its apparent subtlety to the observer, differences in field and captive behavior, and variability of behavior across vast taxa [ 61 , 62 ]. The behavioral changes in this study noted between temperatures, not just treatment status alone, emphasize the caveats of relying solely on behavioral indicators to detect illness in reptiles without considering other impactful variables such as temperature.…”

The Effect of Enrichment on Leopard Geckos (Eublepharis macularius) Housed in Two Different Maintenance Systems (Rack System vs. Terrarium)

“…In the case of the mass breeding of reptiles, rack systems are the most common forms of maintenance, especially for lizards and small snakes, and Herptek is more commonly used for bigger species [ 12 , 13 ]. However, this type of maintenance involves significant space constraints, which can result in diminished animal welfare and reduced expression of species-specific behaviors [ 14 , 15 ].…”

Environmental enrichment for reptiles in European zoos: Current status and perspectives

“…Boissy et al 2007 ; Mellor 2016 ; Yeates 2016 ; Williams et al 2018 ; Yon et al 2019 ), and to move progressively towards the use of animal-based welfare measures to complement and validate resource-based measurements (e.g. Hewitt & Small 2021 ; Whittaker et al 2021 ; Augustine et al 2022 ; Howard & Freeman 2022 ).…”