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Providing evidence to improve practice

Action: Provide supplementary water to increase survival or reproductive success Bird Conservation

Key messages

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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.


Supporting evidence from individual studies


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.


Referenced papers

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. (2019) Bird Conservation. Pages 141-290 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.