Action Synopsis: Bird Conservation About Actions

Provide supplementary food to allow the rescue of a second chick

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

Study locations

Key messages

A small controlled study in Spain found that second chicks from lammergeier Gypaetus barbatus nests survived longer if nests were provided with food, allowing one chick to be rescued.


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 small controlled study in the Spanish Pyrenees in spring 2004-5 and 2008 (Margalida et al. 2009) found that second-hatched lammergeier (bearded vulture) Gypaetus barbatus chicks from two nests provided with supplementary food survived for nine days, as opposed to seven, five and four days for a partially-supplemented nest and two control (unfed) nests, respectively. In a third supplemented nest (in 2008), the second-hatched chick survived for five days and was removed to be hand-reared and incorporated into a captive-breeding programme. Supplementary food consisted of 2-3 kg of dead rabbits within 100 m of the nests every two days from the hatching of the first chick until the death (or removal) of the second chick. The partially-supplemented nest was provided with food on just one day.

    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 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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