Action Synopsis: Bird Conservation About Actions

Provide supplementary water to increase survival or reproductive success

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

Study locations

Key messages

A controlled study in Morocco found that water supplemented northern bald ibis Geronticus eremite pairs had significantly higher reproductive success than those far from water sources.


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 controlled, multi-year study between 1998 and 2002 in coastal semi-desert steppe in southern Morocco (Smith et al. 2008) found that northern bald ibis Geronticus eremite pairs nesting less than 1 km from supplementary water points had significantly higher reproductive success than pairs nesting more than 5 km from water points (all nests: 1.0-2.2 fledglings/nest for nests close to water vs. 0.37-1.6 fledglings/nest for distant nests; only successful nests: 1.3-2.4 fledglings/nest vs. 1.0-2.3 fledglings/nest). There were no differences in clutch size between treatments, so the authors suggest that differences in productivity were due to failure rates, with 11% of 105 nests close to water failing, compared to 38% of 74 nests far from water. The increase was greatest in years of low natural rainfall but apparent in all years.

    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