Contributions of the Conservation Reserve Program to Populations of Breeding Birds in North Dakota

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)

Species
1992
1993
BBS
trenda
CRP Crop CRP Crop
Lark Bunting
(Calamospiza melanocorys)
24.2 2.0 8.6 1.3 -4.22*
Grasshopper Sparrow
(Ammodramus savannarum)
20.3 1.3 11.7 0.6 -4.58*
Red-winged Blackbird
(Agelaius phoeniceus)
19.4 1.9 9.7 0.9 -0.04
Savannah Sparrow
(Passerculus sandwichensis)
6.5 0.1 8.1 1.5 0.63
Western Meadowlark
(Sturnella neglecta)
6.1 1.3 6.4 1.2 -0.32
Brown-headed Cowbird
(Molothrus ater)
6.3 1.1 4.6 1.5 -0.26
Bobolink
(Dolichonyx oryxivorus)
7.4 2.8 3.9 2.1 -2.74
Clay-colored Sparrow
(Spizella pallida)
4.5 0.0 4.0 0.0 -2.08*
Common Yellowthroat
(Geothlypis trichas)
2.1 0.0 2.1 0.0 -0.32
Horned Lark
(Eremophila alpestris)
2.2 20.1 1.0 29.1 0.15
Mourning Dove
(Zenaida macroura)
1.8 1.7 0.9 1.6 -0.07
Sedge Wren
(Cistothorus platensis)
1.0 0.0 1.5 0.0 -0.97
Vesper Sparrow
(Pooecetes gramineus)
1.7 1.8 0.7 2.9 0.24
Baird's Sparrow
(Ammodramus bairdii)
0.2 0.3 1.4 0.0 -2.58*
Dickcissel
(Spiza americana)
1.5 0.2 0.1 0.0 -1.44*
Upland Sandpiper
(Bartramia longicauda)
0.4 0.9 0.2 0.7 4.14*
Chestnut-collared Longspur
(Calcarius ornatus)
0.3 1.4 0.2 2.1 -0.47
Killdeer
(Charadrius vociferus)
0.1 1.1 0.0 1.2 0.25

a Asterisk indicates a significant (P< 0.05) trend.

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