Boldness towards novelty and translocation success in captive‐raised, orphaned Tasmanian devils

Abstract

Translocation of endangered animals is common, but success is often variable and/or poor. Despite its intuitive appeal, little is known with regards to how individual differences amongst translocated animals influence their post-release survival, growth, and reproduction. We measured consistent pre-release responses to novelty in a familiar environment (boldness; repeatability=0.55) and cortisol response in a group of captive-reared Tasmanian devils, currently listed as "Endangered" by the IUCN. The devils were then released at either a hard- or soft-release site within their mothers' population of origin, and individual growth, movement, reproduction (females only), and survival across 2-8 months post-release was measured. Sex, release method, cohort, behavior, and cortisol response did not affect post-release growth, nor did these factors influence the home range size of orphan devils. Final linear distances moved from the release site were impacted heavily by the release cohort, but translocated devils' movement overall was not different from that in the same-age wild devils. All orphan females of reproductive age were subsequently captured with offspring. Overall survival rates in translocated devils were moderate (∼42%), and were not affected by devil sex, release method, cohort, release weight, or pre-release cortisol response. Devils that survived during the study period were, however, 3.5 times more bold than those that did not (effect size r=0.76). Our results suggest that conservation managers may need to provide developmental conditions in captivity that promote a wide range of behaviors across individuals slated for wild release.

Sympathy for the devil: captive-management style did not influence survival, body-mass change or diet of Tasmanian devils 1 year after wild release

“…In contrast to our prediction, Tasmanian devils raised in IC facilities did not experience lower survivorship. The proportion of captive-bred founders surviving on Maria Island was higher (~96% over 2 years) than that observed for animals released on the mainland (~42% over 2-8 months) in the study of Sinn et al (2014).…”

“…Largely because of this low survival of released captivebred animals, a great deal of debate has surrounded the value of captive-raised founders for conservation programs (Armstrong and Seddon 2008;Jule et al 2008). The generally low success rate in releases of captive-raised founders, including devils (Sinn et al 2014), has been a concern for managers of the Tasmanian devil program. Over the long-term, captive-raised devils are an important part of the conservation strategy to maintain devil insurance populations, while DFTD moves through the wild population.…”

“…Captive-reared Tasmanian devils released onto the Tasmanian mainland had moderate survival (~42%) 2-8 months postrelease (Sinn et al 2014). Twenty-eight DFTD-free captive devils have been released onto Maria Island (a devil-free Tasmanian island), and the present study examines their survival and diet.…”

The ecological and life history correlates of boldness in free‐ranging lizards

“…Boldness can be loosely defined as the propensity of an animal to engage in risky behavior (be it through exploring a novel item of prey, interaction with a predator, or time spent in risky areas; Wilson and Godin , Sinn et al. ). To ensure the validity of our target personality trait, we measured behaviors in different contexts.…”

Happily ever after? Fates of translocated nuisance woodchucks in the Chicago metropolitan area

“…The presence of other woodchucks occupying territories in the release area could have limited movements of translocated woodchucks, and this limitation could fluctuate over time with population dynamics causing the observed variation. An alternative explanation is that individual variation in movement behavior could be suggestive of a behavioral type, which can have consequences for fitness (Smith and Blumstein 2008;Sinn et al 2014). Although we observed no relationship between this particular behavioral trait and survival for woodchucks, understanding whether intraspecific behavioral variation relates to translocation success requires additional research.…”