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Providing evidence to improve practice

Individual study: Effect of herbicide spraying on densities of American coot Fulica americana and sora Porzana carolina in wetlands near Lakota, North Dakota, USA

Published source details

Linz G.M., Bergman D.L., Blixt D.C. & McMurl C. (1997) Response of American coots and soras to herbicide-induced vegetation changes in wetlands. Journal of Field Ornithology, 68, 450-457


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Treat wetlands with herbicide Bird Conservation

A controlled, replicated before and after study in 1990-1993 in 20 inland wetlands in North Dakota, USA (Linz et al. 1997), found that, two years after treatment, densities of American coot Fulica americana were significantly higher at wetlands sprayed with herbicide  (0.8-1.0 birds/ha) than at untreated sites (0.2 birds/ha), but that sora Porzana carolina densities were significantly lower (0.1-0.3 birds/ha vs. 0.5). Coot densities were positively correlated with extent of open water and negatively with live emergent vegetation; sora densities were positively correlated with live emergent vegetation. Four sites had 90% coverage with glyphosate (aerially applied), eight had 70% coverage, four 50% and four were controls, with no coverage. No coots were found on any wetlands before treatment.