Providing evidence to improve practice

Action: Provide refuges for fish within ponds Bird Conservation

Key messages

A controlled cross-over trial in the UK found that great cormorant Phalacrocorax carbo foraging success was lower in a pond with artificial refuges, compared to a control pond.

 

Supporting evidence from individual studies

1 

In Berkshire, England, a controlled cross-over trial (in the winters of 2003 and 2004) found that great cormorant Phalacrocorax carbo foraging success was lower in a pond with artificial refuges (Russell et al. 2008), compared to a control pond (on average, 67% less fish weight consumed/cormorant visit); fish loss was significantly lower (79% less fish weight lost); and there were 77% fewer cormorant visits. Two adjacent ponds (45.0 x 27.2 m; 1.35 m depth) were used, with provided in one pond each year. Refuges were 12 mesh covered cages (2 x 2 x 1.2 m high) in two blocks of six, with shade cloth and containing 4-6 tree saplings to provide cover. At commencement of each trial, ponds were similarly stocked with freshwater fish. Fish weight was recorded at the beginning and end of each trial.

 

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. (2017) Bird Conservation. Pages 95-244 in: W.J. Sutherland, L.V. Dicks, N. Ockendon & R.K. Smith (eds) What Works in Conservation 2017. Open Book Publishers, Cambridge, UK.