Northern Prairie Wildlife Research Center
Contributions of the Conservation Reserve Program to Populations of Breeding
Birds in North Dakota
Douglas H. Johnson and Lawrence D. Igl
ABSTRACT--Previous studies have shown that habitat provided by the Conservation
Reserve Program (CRP), a feature of the 1985 farm bill, is used by many birds.
The present study quantitatively assesses the importance of the CRP by estimating
changes in breeding-bird populations of North Dakota projected if CRP land would
revert to cultivation. Of 18 species that were common in CRP or crop fields
or both, 12 were more abundant in CRP habitats. Six of these species had suffered
significant population declines during 1967-90, according to the North American
Breeding Bird Survey. In contrast, none of the six species that were more common
in cropland than in CRP fields had declined significantly. Termination of the
Conservation Reserve Program and a return of enrolled land to cultivation is
projected to cause population declines in North Dakota exceeding 17% for Sedge
Wren (Cistothorus platensis), Grasshopper Sparrow (Ammodramus savannarum),
Savannah Sparrow (Passerculus sandwichensis), Dickcissel (Spiza americana),
and Lark Bunting (Calamospiza melanocorys). Received 27 October 1994,
accepted 11 May 1995.
This resource is based on the following source (Northern Prairie Publication
0949):
Johnson, Douglas H. and Lawrence D. Igl. 1995. Contributions of the
Conservation Reserve Program to Populations of Breeding Birds in
North Dakota. Wilson Bulletin 107(4), pp. 709-718.
This resource should be cited as:
Johnson, Douglas H. and Lawrence D. Igl. 1995. Contributions of the
Conservation Reserve Program to Populations of Breeding Birds in
North Dakota. Wilson Bulletin 107(4), pp. 709-718. Jamestown,
ND: Northern Prairie Wildlife Research Center Online.
http://www.npwrc.usgs.gov/resource/birds/crpcont/index.htm
(Version 16JUL97).
Table of Contents
Tables
- Table 1 -- Densities of Breeding Birds (Number
of Pairs per 100 HA) in North Dakota in CRP Fields and Crop Fields, 1992
and 1993, and Trends in Abundance Estimated From Midcontinental Breeding
Bird Surveys (1967-1990)
- Table 2 -- Estimated Numbers of Breeding Pairs
(1000's) Statewide, in Conservation Reserve Program Fields, and Percentage,
in North Dakota, 1992 and 1993
- Table 3 -- Estimated Number of Breeding Pairs (1000's)
of Birds in CRP Fields in North Dakota, Estimated Number if CRP were Cropland,
Predicted Change in Breeding Pairs, Statewide Number of Breeding Pairs,
and Predicted Change as Percentage of Statewide Population, Mean Values
for 1992-1993
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