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Providing evidence to improve practice

Individual study: Waterbird responses to experimental drawdown of wetlands at the Grasslands Ecological Area, California, USA

Published source details

Taft O.W., Colwell M.A., Isola C.R. & Safran R.J. (2002) Waterbird responses to experimental drawdown: implications for the multispecies management of wetland mosaics. Journal of Applied Ecology, 39, 987-1001


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Manage water level in wetlands Bird Conservation

A replicated partially-randomised, controlled study compared waterbird use of four experimentally drawndown wetlands with flooded wetlands at the Grasslands Ecological Area in California's Central Valley, USA (Taft et al. 2002), found that maximum bird diversity and abundance occurred at average depths of 10-20 cm on wetlands with a 30-40 cm difference between deepest and shallowest zones. There was limited availability of shallow-water habitat in winter but not spring, allowing waders, cinnamon teal Anas cyanoptera and American green-winged teal A. carolinensis to use the site. Use by deeper-water dabbling ducks and diving waterbirds declined during later stages of drawdown. Birds were monitored over winter and spring 1994-1995.