Individual study: Semipermanent wetlands with active hydrologic management increase waterbird species richness, waterfowl reproduction and use by migratory species
O'Neal B.J., Heske E.J. & Stafford J.D. (2008) Waterbird Response to Wetlands Restored Through the Conservation Reserve Enhancement Program. Journal of Wildlife Management, 3, 654-664
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Restore or create inland wetlands
A replicated, randomised study in spring from 2004-5 in 28 small restored wetlands in Illinois, USA (O'Neal et al. 2008), found that semi-permanent wetlands were used more frequently by waterbirds than temporary or seasonal wetlands and held more waterfowl broods (semi-permanent wetlands were used on 56% of days and held 1.1 broods/ha vs. 37% and 0.2 for seasonal and 7% and zero broods for temporary wetlands). Hydrologic management (passive restoration and management; active restoration through hydraulic engineering but passively managed or actively restored and managed through regulation of hydrologic regime) was the most important variable in explaining bird abundance and distributions. Of the 28 wetlands, 25 were <5 ha in size and 17 were <1 ha. Water birds included waterfowl, wading birds and shorebirds. Wetlands were classified as semi-permanent if there was surface-water throughout growing season; seasonal if there was surface water at the start, and for long periods of the growing season, but not by the end of it; and temporary if surface-water was only found for brief periods throughout the growing season.