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Providing evidence to improve practice

Action: Alter artificial nest sites to discourage brood parasitism Bird Conservation

Key messages

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A replicated trial from Puerto Rico found that brood parasitism levels were extremely high across all nest box designs tested.


Supporting evidence from individual studies


A replicated trial in 1980 in Puerto Rico (Wiley et al. 1991) found that, shiny cowbirds Molothrus bonariensis parasitised yellow-shouldered blackbird Agelaius xanthomus nests in all 16 nest box types tested with 96% of 103 nests parasitised. The effect of cowbird control is discussed in ‘Threat: Invasive and other problematic species - Remove/control brood parasites’.


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.