Personality in Zoo-Hatched Blanding’s Turtles Affects Behavior and Survival After Reintroduction Into the Wild

Abstract

Reintroduction programs in which captive-bred or reared animals are released into natural habitats are considered a key approach for conservation; however, success rates have generally been low. Accounting for factors that enable individual animals to have a greater chance of survival can not only improve overall conservation outcomes but can also impact the welfare of the individual animals involved. One such factor may be individual personality, and personality research is a growing field. We designed a project to ascertain the presence of personality traits in Blanding’s turtles (Emydoidea blandingii), a species of special concern in the state of Michigan, and to assess potential links between traits and post-release success. As hypothesized, the Blanding’s turtles in this study displayed behavioral responses to modified open field tests indicative of distinct personality traits: exploration, boldness, and aggression. Additionally, the personality traits were correlated differently with survival and behavior patterns when the turtles were released into the Shiawassee National Wildlife Refuge. More exploratory turtles had higher survival rates, while neither boldness nor aggression was related to survival. Exploratory turtles were also more likely to travel longer distances after release. The use of muskrat dens was related to increased survival, and both bolder and more exploratory turtles made higher use of this feature. Exploratory and aggressive turtles were found basking outside of water more often, while bold turtles were more likely to be found at the water surface. Both these basking behaviors may increase the risk of predation and may be reflective of a trade-off between the risk and behaviors related to physiological health. Understanding how personality affects behavior and survival post-release can be a critical tool for improving reintroduction success. Zoo animal welfare scientists and practitioners can implement approaches that improve the welfare of individuals within the context of conservation initiatives.

Iberian Lynx (Lynx pardinus) personality: A rating assessment with ex Situ Conservation Program sample.

“…In this sense, personality has been shown to have an influence on success on breeding in black rhinoceros ( Diceros bicornis; Carlstead et al, 1999), blue tits ( Cyanistes caeruleus ; Mutzel et al, 2013), or giant pandas ( Ailuropoda melanoleuca ; Powell et al, 2008) among others, where in the case of felids, nonbreeder cheetahs were found to score significantly higher on tense-fearful factor than breeder cheetahs (Wielebnowski, 1999). Likewise, it has been found that personality plays a role on successful reintroduction in Blanding’s turtles ( Emydoidea blandingii; Allard et al, 2019), European minks ( Mustela lutreola ; Haage et al, 2017), or wood mouses ( Apodemus sylvaticus; Stratton, 2015), among others. In absence of examples on felids, the swift foxes ( Vulpex velox ) boldness was related with early death after the reintroduction of captive-bred animals (Bremner-Harrison et al, 2004); while with the Tasmanian devils ( Sarcophilus harrissii) boldness was related with higher survival rates (Sinn et al, 2014).…”

Animal Personality and Conservation: Basics for Inspiring New Research

“…However, why did this happen and is this true for all species? After the publication of this study, there have been calls in the literature to include personality assessment in translocations/animal releases, and boldness, exploration, activity, and sociability became the most studied aspects of personality-conservation dyad [ 41 , 67 , 68 , 69 ].…”

“…Bolder animals are more prone to take risks, because they explore more their environment, get closer to predators, sample more food items, etc. [ 66 , 68 , 70 ]. By doing this, bolder animals may die sooner than shyer animals [ 66 ].…”

“…In a study of 23 captive-born Blanding’s turtles ( Emydoidea blandingii ), researchers found that turtles presented different personality traits in the aggressiveness, boldness, and exploratory dimensions [ 68 ]. After reintroduction, more exploratory turtles survived more than less exploratory turtles, the exploratory dimension being the only one that influenced survival.…”

Behaviorual instability in two African wild dogs in Aalborg Zoo

“…In addition, the lack of success in reproduction can be a sign of the individual not being able to express species-specific behaviour, which can indicate lack of animal welfare (Gusset & Macdonald 2010;Yordy & Mossotti 2016). When looking at personality, there are signs of difference in personality between individuals based on significant difference in behavioural reaction patterns, which can indicate animal welfare (Allard et al 2019).…”