Habitat drives dispersal and survival of translocated juvenile desert tortoises

Published source details Nafus M.G., Esque T.C., Averill-Murray R.C., Nussear K.E. & Swaisgood R.R. (2017) Habitat drives dispersal and survival of translocated juvenile desert tortoises. Journal of Applied Ecology, 54, 430-438.
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This study is summarised as evidence for the following.

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	Release captive-bred reptiles into the wild: Tortoises, terrapins, side-necked & softshell turtles Action Link

Release captive-bred reptiles into the wild: Tortoises, terrapins, side-necked & softshell turtles

A replicated study in 2014–2015 in four desert scrub vegetation sites in Nevada, USA (Nafus et al. 2017) found that more than half of released captive-bred juvenile Mojave desert tortoises Gopherus agassizzii survived at least six months and settled into home ranges within two months of release. Six months to one year after release, 53 of 80 (66%) released captive-bred juvenile desert tortoises were still alive. The authors reported that of 25 known tortoise deaths, 14 were due to starvation or exposure, and the remaining 11 showed signs of predation or scavenging. Overall, 46 of 71 (65%) desert tortoises settled into a home range pattern within two weeks, all 71 had settled within two months, and nine died before establishing a home range. In September 2014 and April 2015, eighty desert tortoises were hatched and reared in captivity (ages ranged from 6 months to 4 years) and released into four different locations in the Mojave Desert (19–21 tortoises released/locations). Tortoises were released at least 20 m apart and radio tracked weekly during March–October and every two weeks during November–February from release until September 2015. Two tortoises lost their transmitters and were excluded from survival numbers.

(Summarised by: Katie Sainsbury)