Short-term effects of handling and permanently marking gopher tortoises (Gopherus polyphemus) on recapture rates and behavior

Pike, David A.; Dinsmore, A. H.; Crabill, Trisha; Smith, Rebecca B.; Seigel, Richard A.

doi:10.1163/1570754043492054

Cited by 16 publications

(1 citation statement)

References 19 publications

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“…Neck extension and retraction has been observed in surprisingly few studies although it has been suggested that tortoises will retract into their shell when startled, which is often an avoidance response to a possible threat or stressor. For instance, Pike et al (2005) observed that tortoises that experienced frequent handling often resisted by kicking and hissing and, on release, would remain retracted in their shell for some time before retreating into a burrow. This would suggest that retracting into their shells is a response of anxiety and an avoidance or defense behavior in response to a potential threat, and that neck extension, in contrast, relates to a more relaxed state.…”

Section: Tortoisesmentioning

confidence: 99%

Response to novelty as an indicator of reptile welfare

Moszuti

Wilkinson

Burman

2017

Applied Animal Behaviour Science

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Whilst a great deal of research has been focused on identifying ways to assess the welfare of captive mammals and birds, there is comparatively little knowledge on how reptilian species are affected by captivity, and the ways in which their welfare can be accurately assessed. The present study investigated response to novelty -a commonly used approach to assess anxiety-like behaviour and hence welfare in non-human animals -in two species of reptile with the aim of determining whether this approach could be successfully translated from use in mammalian and avian species for use in reptiles, and whether we could also identify reptile-specific and/or species-specific behaviours. Eight red-footed tortoises (Chelonoidis carbonaria) and seventeen bearded dragons (Pogona vitticeps) were observed individually in both familiar and novel environments for 10 minute time periods, and their behaviour recorded. Tortoises were found to begin locomotion sooner when placed in a familiar environment than when placed in a novel environment, they extended their necks further in a familiar environment and their neck length increased over time in both familiar and novel environments, suggesting an overall anxiety-like response to novelty as seen in non-reptilian species. In contrast, whilst bearded dragons exhibited significantly more tongue-touches in a novel, compared to a familiar, environment, they showed no difference between familiar and novel environments in their latency to move. This result suggests that, whilst the dragons appeared to discriminate between the two environments, this discrimination was not necessarily accompanied by an anxiety-like response.This study has confirmed the translatability of response to novelty as an approach to assess anxietylike behaviour in one species of reptile, as well as identifying species-specific behaviours that have the potential to be used in future studies when assessing the welfare of reptiles in response to captive environments, but our results also highlight the need to be aware of species differences within a class as diverse as reptilia.

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Section: Tortoisesmentioning

confidence: 99%

Response to novelty as an indicator of reptile welfare

Moszuti

Wilkinson

Burman

2017

Applied Animal Behaviour Science

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Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates

et al. 2021

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Accurate population estimates are essential for monitoring and managing wildlife populations. Mark-recapture sampling methods have regularly been used to estimate population parameters for rare and cryptic species, including the federally listed Mojave desert tortoise (Gopherus agassizii); however, the methods employed are often plagued by violations of statistical assumptions, which have the potential to bias density estimates. By incorporating spatial information into conventional density estimation models, spatial capture-recapture (SCR) models can account for common assumption violations such as spatially heterogeneous detection probabilities and temporary emigration when animals leave plots during a survey. We conducted mark-recapture surveys at 10 1-km 2 plots in and adjacent to the Ivanpah Valley of California and Nevada from 2015 to 2019. Locality data were collected concurrently using radio-telemetry and GPS data loggers. GPS data demonstrated that desert tortoises frequently exhibited temporary emigration outside a plot during the survey periods, thereby complicating standard approaches for closed-model density estimation. We integrated mark-recapture survey data for subadults and adults at each plot with corresponding spatial capture locations and supplementary spatial data using a modified SCR model fitted in a Bayesian framework. We compared density estimates modeled with conventional non-spatial methods, as well as three SCR models based on symmetrical usage areas described by various levels and types of supplementary spatial data. The conventional model consistently resulted in inflated estimates of density while the SCR models allowed us to generate spatially corrected estimates for a species where detectability and densities are low. However, we found that if not properly specified, the temporal scale of supplementary data may result in an unintended source of bias in parameter estimates. Integrating spatial data over a larger temporal scale than mark-recapture surveys were conducted resulted in higher detection probabilities and lower density estimates, due to an overestimation of space use. Our results not only demonstrate the importance of accounting for spatial information but also the value of understanding the potential for bias when integrating multiple data sets at different temporal resolutions. The methods presented can be used to enhance monitoring efforts for the Mojave desert tortoise and other species where mark-recapture methods are used.

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Social Behaviour as a Challenge for Welfare

Doody

2023

Health and Welfare of Captive Reptiles

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Short-term effects of handling and permanently marking gopher tortoises (Gopherus polyphemus) on recapture rates and behavior

Cited by 16 publications

References 19 publications

Response to novelty as an indicator of reptile welfare

Response to novelty as an indicator of reptile welfare

Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates

Social Behaviour as a Challenge for Welfare

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