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bioRxiv · 10.1101/2025.04.14.648616

Give It Time: Green Anacondas Show Prolonged Behavioral Responses to Enclosure Enhancements

Abstract

Information about green anacondas (Eunectes murinus) in human care is limited, especially concerning their behavior, welfare, and overall well-being. To help bridge this knowledge gap, this study evaluated how exhibit design enhancements influence E. murinus behavior. The aim was to assess immediate behavioral changes following enclosure modifications and investigate potential habituation over time, ultimately evaluating the effectiveness and longevity of the behavioral changes induced by the improved environment. Systematic observations were divided into three phases: before enclosure improvements, immediately after these modifications, and three weeks later. Enclosure modifications focused on areas less frequented by the anacondas during Phase 1. Results revealed decreased inactivity in Phase 2 and more balanced space use in Phase 3, with anacondas occupying previously underutilized areas, including the terrariums vertical dimension. Interaction with exhibit enhancement items increased in the studys final phase, where a decrease in engagement would be anticipated due to habituation. These results suggested the anacondas required additional time to acclimate to the modifications, even though environmental factors may have contributed to these changes. This study highlights how enclosure enhancements may benefit green anacondas welfare while underlining the importance of providing sufficient acclimation time to accurately evaluate the animals complete behavioral response. Simple SummaryGreen anacondas (Eunectes murinus) remain largely understudied, particularly in terms of their behavior and welfare in human care. To address this knowledge gap, improvements were made to the enclosure of green anacondas in captivity, and their behaviors were observed before and after the modifications. The observations were divided into three phases: before the changes (Phase 1), immediately after (Phase 2), and approximately three weeks later (Phase 3). The modifications focused on areas that were rarely utilized during Phase 1. After the improvements, the anacondas became more active and used their enclosure more evenly, including at varying heights. The anacondas interacted more with the new enclosure features after the three weeks, when increased disinterest would have been expected, although environmental conditions may have influenced these changes. These findings show how enclosure modifications may help enhance the welfare of green anacondas and emphasize the need for research that allows enough time for the animals to fully adjust, ensuring a complete understanding of their response.

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Carvalho, J., Poinho, M. I., Morello, G., Ramos, F., Magalhaes, A.. 2025-04-16. Give It Time: Green Anacondas Show Prolonged Behavioral Responses to Enclosure Enhancements. https://doi.org/10.1101/2025.04.14.648616

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