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Providing evidence to improve practice

Individual study: Nest density and reproductive success of blue-winged teal Anas discors in response to grazing and hay-making, Union Slough National Wildlife Refuge, Iowa, USA

Published source details

Burgess H.H., Prince H.H. & Trauger D.L. (1965) Blue-winged teal nesting success as related to land use. The Journal of Wildlife Management, 29, 89-95


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

Employ grazing in natural grasslands Bird Conservation

At Union Slough National Wildlife Refuge, Iowa, USA (Burgess et al. 1965), a replicated, controlled trial in 1959-1961 found that blue-winged teal Anas discors nests in grazed grasslands and hayfields had greater success rates than those in ungrazed areas (47% success for grazed areas vs. 46% in hayfields and 14% in ungrazed areas; a total of 111 nests were monitored). However, nesting density was higher in ungrazed areas (7 nests/ha) than in grazed areas (4 nests/ha) or hayfields (4/ha). Areas were moderately grazed (15 June-1 October), ungrazed, or hay-cut (July-August, after the main nesting period).  Most nests were in Kentucky bluegrass Poa pratensis and alfalfa Medicago sativa.