Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Action: Control predators not on islands for rails Bird Conservation

Key messages

Read our guidance on Key messages before continuing

A single study from the USA found more California clapper rails Rallus longirostris obsoletus on sites with higher numbers of foxes removed.


Supporting evidence from individual studies


An analysis of data from 24 sites in south San Francisco Bay, USA, between 1991 and 1996 (Harding et al. 2001) found that the number of California clapper rails Rallus longirostris obsoletus surveyed each winter was positively correlated with the capture rate of red foxes Vulpes vulpes the previous year. At one site, the rail population increased from 40 in 1989 to 104 in 1994. Over the study period, the number of foxes trapped remained relatively constant (66-94/year) despite increased trapping effort, suggesting population decline.  However, the authors suggest that fox immigration into the area meant that predator control would only be effective in the short term.


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.