An assessment of mitigation translocations for reptiles at development sites


This study is summarised as evidence for the following.

Action Category

Use holding pens or enclosures at release site prior to release of wild reptiles

Action Link
Reptile Conservation

Translocate reptiles away from threats: Snakes and lizards

Action Link
Reptile Conservation
  1. Use holding pens or enclosures at release site prior to release of wild reptiles

    A randomized, controlled study in 2016–2017 in an area of mixed grassland, scrub and woodland in Kent, UK (Nash 2017) found that more translocated viviparous lizards Zootoca vivipara were recaptured after release into an enclosure compared to those released in an unenclosed area, and that body condition was similar in the enclosed and unenclosed areas. More lizards were resighted after release in the enclosure (101 lizards) than in the unenclosed area (16 lizards). Body condition was similar for lizards in the enclosure and those in the unenclosed area (reported as condition index). Two adjacent sites in the wider release area (1.5 ha each) were selected, and one was randomly selected and enclosed with a reptile-proof fence (38 cm high, buried 30 cm deep). Both sites were provisioned with one hibernaculum and four earth banks. In 2016, lizards were translocated to both sites in the release area (total of 1,364 lizards) and 695 were released in the enclosure and 669 were released in the unenclosed area. In April–May 2017, translocated lizards were monitored at the two sites using visual encounter surveys and artificial cover boards (45/site).

    (Summarised by: William Morgan)

  2. Translocate reptiles away from threats: Snakes and lizards

    A site comparison study in 2013–2015 in two areas of mixed woodland and grassland in Kent, UK (Nash 2017, same experimental set-up as Platenberg & Griffiths 1999) found that a translocated population of slow worms Anguis fragilis was still present 20 years later, and that males at the release site had higher body condition compared to males from another population, but immature slow worms had lower condition. Twenty years after release, a total of 59 slow worms were observed at the release location. Annual population estimates were 74 individuals in 2013, 44 in 2014 and 20 in 2015, and annual survival was estimated at 56% for females and 23% for males. Males at the release site had higher body condition than males from another natural population, whereas immature slow worms at the release site had lower condition than those from the natural population (results reported as condition index). In 1994, a population of 134 slow worms was translocated away from a residential development on a brownfield site and held in a temporary holding enclosure. After one year, 103 slow worms were captures from the enclosure and translocated to small island (1.7 ha) within a river. In 2013–2015, the population was monitored in April–September using artificial cover boards (53 boards: 0.5 m2 each). Monitoring was also carried out at another location with a natural population of slow worms. Size and weight of all slow worms was measured at the time of capture.

    (Summarised by: William Morgan)

Output references
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