Action Synopsis: Bird Conservation About Actions

Translocate owls

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • A small study from New Zealand found that translocating two male boobook Ninox novaeseelandiae novaeseelandiae allowed the establishment of a small population, when they interbred with the last remaining Norfolk Island boobook N. n. undulata
  • A replicated study in the USA found high survival amongst burrowing owls Athene cunicularia translocated as juveniles, although no breeding was recorded and all birds left the release site and were not seen again.


About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A study on Norfolk Island, Australia (Olsen 1996), found that the last remaining Norfolk Island boobook Ninox novaeseelandiae undulata (a female) paired with one of two male boobooks N. n. novaeseelandiae introduced from New Zealand in 1987 (the other disappeared shortly after release). The pair attempted unsuccessfully to breed in 1988 and 1991-3 but succeeded in 1989 and 1990, and fledged a total of four young. Two of these subsequently bred successfully themselves in 1993 and 1994, increasing the population to eleven birds, all alive in 1995.

    Study and other actions tested
  2. A replicated study reviewing a reintroduction programme in Minnesota, USA (Martell et al. 2001), found that only eight of 105 (8%) burrowing owl Athene cunicularia juveniles translocated from South Dakota to Minnesota in 1986-90 were confirmed mortalities, with all other birds seen well past fledging age. However, no birds were seen after leaving the vicinity of the release site and no successful breeding attempts were recorded between 1992 and 1998. Birds were released at prairie sites in the species’ former range using ‘hacking pens’ (see ‘Release captive-bred individuals into the wild to restore or augment wild populations’) and were fed for 33 days after release. In addition, artificial burrows were used to reduce predation chances and adult owls used as ‘parental models’.

    Study and other actions tested
Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.


Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Bird Conservation

This Action forms part of the Action Synopsis:

Bird Conservation
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What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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