Study

A hatchling gopher tortoise (Gopherus polyphemus) care protocol for experimental research and head-starting programs

  • Published source details Holbrook A.L., Jawor J.M., Hinderliter M. & Lee J.R. (2015) A hatchling gopher tortoise (Gopherus polyphemus) care protocol for experimental research and head-starting programs. Herpetological Review, 46, 538-543.

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

Relocate nests/eggs for artificial incubation: 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 replicated study in 2010–2013 in two pine forest sites in Mississippi, USA (Holbrook et al. 2015) found that almost two-thirds of released head-started gopher tortoises Gopherus polyphemus survived at least three months in the wild and while in captivity grew bigger than captive-born gopher tortoises of the same age that were released immediately after hatching. In one site, nine of 10 radio-tracked head-started gopher tortoises survived at least one year after release. At a second site, two of 10 radio-tracked head-started gopher tortoises survived at least three months (of the remaining tortoises, seven were predated and the fate of one was unknown). Two-year-old head-started hatchlings were longer and weighed more (carapace length: 97 mm, weight: 204 g) at time of release than two-year-old tortoises that were released into the wild immediately after hatching (carapace length: 62 mm, weight: 53 g). In 2010, ninety-three gopher tortoise eggs were collected from two locations in the wild in May–June and relocated for artificial incubation. Thirty-one hatchlings were head-started for two years in individual indoor containers (see paper for details), and 20 hatchlings were released immediately after hatching. From June–July 2012, head-started hatchlings were housed in individual outdoor enclosures (2 x 2 m). They were released in August 2012 into two sites (after five days in release pens), and 10 tortoises/site were radio tracked three times/week until the end of the radio transmitters lifespan. Head-started tortoise size/weights were compared to the 20 two-year-old tortoises released as hatchlings at one of the release sites.

    (Summarised by: Katie Sainsbury)

  2. Relocate nests/eggs for artificial incubation: Tortoises, terrapins, side-necked & softshell turtles

    A replicated study in 2010 in pine forest and artificial conditions in Mississippi, USA (Holbrook et al. 2015) found that less than half of artificially incubated gopher tortoise Gopherus polyphemus eggs collected from two sites hatched successfully in captivity. Fourteen of 46 (30%) artificially incubated gopher tortoise eggs collected from one site and 22 of 47 (47%) artificially incubated gopher tortoise eggs collected from a second site hatched successfully in captivity. Three hatchlings died within three days of emerging and one never gained function of its rear legs. Ninety-three gopher tortoise eggs were collected from two sites within 24 hours of deposition in May–June 2010 and relocated for artificial incubation. Eggs were placed in dampened vermiculite (0.7 g water to 1.0 g vermiculite) in individual sterilized containers and incubated at 29.3°C. Eggs were collected as part of a head-start programme.

    (Summarised by: Katie Sainsbury)

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