Study

Soft-release versus hard-release for reintroduction of an endangered species: An experimental comparison using eastern barred bandicoots (Perameles gunnii)

  • Published source details De Milliano J., Di Stefano J., Courtney P., Temple-Smith P. & Coulson G. (2016) Soft-release versus hard-release for reintroduction of an endangered species: An experimental comparison using eastern barred bandicoots (Perameles gunnii). Wildlife Research, 43, 1-12

Actions

This study is summarised as evidence for the following.

Action Category

Release captive-bred mammals into fenced areas

Action Link
Terrestrial Mammal Conservation

Release translocated/captive-bred mammals in areas with invasive/problematic species eradication/control

Action Link
Terrestrial Mammal Conservation

Use holding pens at release site prior to release of captive-bred mammals

Action Link
Terrestrial Mammal Conservation
  1. Release captive-bred mammals into fenced areas

    A randomized, controlled study in 2005 in a grassland and forest site in Victoria, Australia (De Milliano et al. 2016) found that captive-bred eastern barred bandicoots Perameles gunnii released into a fenced reserve after time in holding pens had similar post-release survival and body weight compared to bandicoots released directly from captivity. Four out of six bandicoots (67%) released after time in holding pens survived at least 22 days after release, which was similar to the five out of six bandicoots (83%) released directly that survived this period. Maximum weight loss (released from pen: 13%; released directly: 13% loss of weight when released) and final weight 3–4 weeks after release (released from pen: 97%; released directly: 98% of weight when released) were similar. Twelve adult captive-bred bandicoots were randomly divided into two groups of six. One group was kept in a 1-ha pre-release pen (500m from the eventual release site) for one week and provided supplementary food and water and the other group was released directly from captivity. Both groups were released simultaneously into a 170-ha fenced reserve, free of exotic predators. Bandicoots were radio-tracked daily, and were trapped and weighed every 4–5 days, for one month.

  2. Release translocated/captive-bred mammals in areas with invasive/problematic species eradication/control

    A replicated study in 2005 in a grassland and forest site in Victoria, Australia (De Milliano et al. 2016) found that most captive-bred eastern barred bandicoots Perameles gunnii translocated into a fenced reserve where invasive predators had been eradicated survived more than 22 days after release. Nine out of 12 captive-bred bandicoots survived at least 22–26 days after release, when their radio transmitters fell off. Two individuals died within three weeks of release (one was predated by a native eastern quoll Dasyurus viverrinus and one was injured during trapping). The twelfth individual was returned to captivity after losing 21% of its body weight in 10 days. The nine bandicoots which survived had lost 7–19% of their body weight 6–8 days after release, but recovered to 97–98% of their pre-release weight by day 22–26. Twelve captive-bred bandicoots were released into a 170-ha fenced reserve, free of invasive predators. Six of the 12 were kept in a 1-ha pre-release pen for one week and provided with supplementary food and water. Bandicoots were radio-tracked daily, and were trapped and weighed every 4–5 days, for one month.

  3. Use holding pens at release site prior to release of captive-bred mammals

    A randomized, controlled study in 2005 in a grassland and forest site in Victoria, Australia (de Milliano et al. 2016) found that captive-bred eastern barred bandicoots Perameles gunnii kept in holding pens prior to release into a fenced reserve had similar post-release survival and body weight compared to bandicoots released directly from captivity. Four out of six bandicoots (67%) released after time in holding pens survived at least 22 days after release, which was similar to the five out of six bandicoots (83%) released directly that survived this period. Maximum weight loss (released from pen: 13%; released directly: 13% loss of weight when released) and final weight 3–4 weeks after release (released from pen: 97%; released directly: 98% of weight when released) were similar. Twelve adult captive-bred bandicoots were randomly divided into two groups of six. One group was kept in a 1-ha pre-release pen (500m from the eventual release site) for one week and provided supplementary food and water and the other group was released directly from captivity. Both groups were released simultaneously into a 170-ha fenced reserve, free of invasive predators. Bandicoots were radio-tracked daily, and were trapped and weighed every 4–5 days, for one month.

Output references

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