Action Synopsis: Bird Conservation About Actions

Translocate pelicans

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

Study locations

Key messages

Two reviews of a brown pelican Pelecanus occidentalis translocation programme in the USA found high survival of translocated nestlings and that the target population grew enormously, to over 16,000 nests. The authors note that some of the growth may have been due to immigration from the source populations.


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 review of a 1968-76 brown pelican Pelecanus occidentalis translocation programme between six colonies in Florida and three coastal sites in Louisiana, USA (Nesbitt et al. 1978), found that 98% of 778 nestlings (eight to 11 weeks old) moved survived the journey and were successfully released, although all birds released at one site in 1968-9 died, meaning that all subsequent releases were at a single site. The first breeding in Louisiana was recorded in 1971, when the oldest released birds were three years old, and between 1971 and 1976 a total of 221 young fledged successfully. In 1975, an estimated 35–40% of the standing population of 400–450 pelicans died, probably as a consequence of contamination by endrin (an organochloride pesticide). Birds were provided with food twice daily after release.

    Study and other actions tested
  2. A 2003 review (Holm et al. 2003) of the same translocation programme as in Nesbitt et al. 1978, found that between 1968 and 1980, a total of 1,276 pelican nestlings were translocated and that the population increased exponentially from 1971 until 1999, with a peak of 16,405 nests across seven colonies in 2001 (a peak of eleven colonies was reached in 2000). Nests produced an average of 1.7 nestlings between 1971 and 2001 (with a peak of 2.1 nestlings/nest in 2001), which, combined with pelicans’ long lifespans and a decline in the number of birds in Florida, leads the authors to suggest that the exponential growth of the Louisiana population may have been partly due to immigration from nearby states.

    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
What Works 2021 cover

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.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust