Environmental enrichment impacts discrimination between familiar and unfamiliar human odours in snakes (Pantherophis guttata)

Western Hognose Snakes (Heterodon nasicus) Prefer Environmental Enrichment

The environmental enrichment needs of snakes are often disregarded. Using preference testing, we aimed to shed light on the enrichment preferences of a popular pet species, the western hognose snake (Heterodon nasicus). Snakes' enclosures were divided into enriched and standard sides. The enriched half had substrate for burrowing, interactive stimuli, and a large water dish. The standard half had paper towel substrate and a small water dish. Each side also contained a single shelter. We provided belly heat to create a thermal gradient on one side of the cage. Snakes were observed for 6 days, four times daily. We predicted a preference for enriched conditions and, as snakes are ectothermic, a preference for the warmer side. Snakes were additionally given an exploration assay, to explore whether differences in preference for environmental enrichment interact with boldness levels. We found that hognose snakes preferred enrichment, and the strength of this preference increased over time. Preference for enrichment was stronger when the enriched side was cooler. This may be due to the burrowing tendencies of these snakes. We found no relationship between preference and boldness. These findings emphasise the importance of preference testing in establishing research-informed enrichment opportunities for reptiles.

Using Classical and Operant Conditioning to Train a Shifting Behavior in Juvenile False Water Cobras (Hydrodynastes gigas)

Simple Summary

Positive reinforcement training, a form of operant conditioning that rewards learners for specific behaviors to increase the frequency of that behavior, is widely used as a management tool in modern zoological facilities. This type of training offers several benefits, including improved safety, reduction in animal stress, increased choice and control, and many others. Snakes have been shown to learn using operant conditioning, yet the use of positive reinforcement training is not a widespread practice for these animals. A shaping plan, which describes the steps necessary to achieve the ultimate behavioral goal of following a target into a secondary container from their primary enclosure, was developed for false water cobras (Hydrodynastes gigas). Snakes were given food rewards for performing behaviors related to each goal detailed in the plan. Completion of this shaping plan resulted in a reduction of stress behaviors as the training progressed, as well as a decrease in time between the presentation and snakes interacting with the target.

Abstract

All animals have the capacity to learn through operant conditioning and other types of learning, and as a result, zoos and other animal care facilities have shifted towards the use of positive reinforcement training to shape the behavior of animals under their care. Training offers animals the choice to participate in their own husbandry routines and veterinary procedures, while also providing mental stimulation. By adopting these practices, the welfare of animals in human care has improved, but it has not been applied equally across taxa. Snakes are frequently overlooked in the discussion of choice and control in a captive setting, likely due to the historical misinterpretation of their intelligence and behavioral needs. In this study, a shaping plan was developed for 28 juvenile false water cobras (Hydrodynastes gigas), a rear-fanged venomous species, from four clutches. Snakes were rewarded with food when completing behaviors related to the ultimate goal of following a target into a shift container. The purpose of this study is to incorporate the trained behaviors in routine husbandry practices, while preventing unnecessary stress in the snakes and risk to the keeper.