Study

Post-release dispersal and predation of head-started juvenile desert tortoises (Gopherus agassizii): effect of release site distance on homing behavior

  • Published source details Hazard L.C., Morafka D.J. & Hillard S. (2015) Post-release dispersal and predation of head-started juvenile desert tortoises (Gopherus agassizii): effect of release site distance on homing behavior. Herpetological Conservation and Biology, 10, 504-515.

Actions

This study is summarised as evidence for the following.

Action Category

Head-start wild-caught reptiles for release: Tortoises, terrapins, side-necked & softshell turtles

Action Link
Reptile Conservation
  1. Head-start wild-caught reptiles for release: Tortoises, terrapins, side-necked & softshell turtles

    A study in 2001 in desert scrub in California, USA (Hazard et al. 2015) found that over half of released head-started juvenile desert tortoises Gopherus agassizii survived at least three months in the wild. After 90 days in the wild, nine of 16 (56%) released head-started juvenile tortoises were still alive. The seven dead tortoises died from predation. The authors reported that 13 days after release, 13 of 16 tortoises (81%) had settled into home ranges, and that 54 days after release, tortoises were an average of 174 m from their release location. From 1989, wild-caught hatchling tortoises were reared in predator-proof enclosures. In March 2001, sixteen juvenile tortoises (8–9 years old) were released 500 m from their rearing pen and radio-tracked for 91 days during daylight hours. Tortoises were located 16 times after release.

    (Summarised by: Katie Sainsbury)

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