Individual study: Use of Conservation Reserve Program habitats by breeding birds in North Dakota, USA
Johnson D.H. & Igl L.D. (1995) Contributions of the Conservation Reserve Program to populations of breeding birds in North Dakota. Wilson Bulletin, 107, 709-718
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 grasslands
A replicated, controlled study in the summers of 1992-1993 in North Dakota, USA (Johnson & Igl 2005), found that the 11 of 18 bird species recorded occurred at higher densities in CRP fields, compared to non-CRP fields. CRP fields only covered 7% of land in North Dakota but supported a disproportionate amount of the total state populations of sedge wren Cistothorus platensis (27%), savannah sparrow (23%), grasshopper sparrow (22%), bobolink Dolichonyx oryzivorus (19%) and lark bunting Calamospiza melanocorys (18%).