Action Synopsis: Bird Conservation About Actions

Provide supplementary food for cranes to increase adult survival

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

Study locations

Key messages

A before-and-after study from Japan and a global literature review found that local crane populations increased after the provision of supplementary food.


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 before-and-after study of red-crowned cranes Grus japonensis in Hokkaido, Japan, in the mid-20th century (Masatomi 1991) found that a local population increased from 42 individuals in 1952-4 to 161 in 1960-4. This followed the establishment of an artificial feeding station in 1952, and the author attributes the population rise to supplementary food reducing winter mortality, although no data is provided for the use of the feeding station, any reduction in starvation or increase in reproductive productivity. No details are provided about the supplementary food provided.

    Study and other actions tested
  2. A 1998 literature review (Davis 1998) found that supplementary feeding of cranes appeared to increase local populations five, and possibly six species of crane in five sites across the world. These were red-crowned cranes Grus japonensis in Hokkaido, Japan (Masatomi 1991); hooded cranes G. monachus and white-naped cranes G. vipio wintering at Izumi, Japan; common cranes G. grus at Lake Hornborga, Sweden; and demoiselle cranes Anthropoides virgo at Khichan in India. It is also possible that winter feeding of whooping cranes G. americana in 1993-4 may have encouraged population growth. The author recommends that supplementary feeding is viewed as a potential short-term practice, but that the risks from spreading disease and increased human disturbances may make it unsuitable as a long-term strategy.

    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?

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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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