Avian Use of Forest Habitats in the Pembina Hills of Northeastern North
Dakota
Tables
Table 1. Vegetative characteristics of forest habitats in the Pembina
River study area, North Dakota, 1981.
| Characteristic |
Quaking Aspen |
Lowland forest |
Bur oak |
Willow shrub |
Serviceberry thicket |
| Trees per hectare |
595 |
492 |
178 |
7.4 |
0 |
| Basal area (m²) |
3.8 |
5.4 |
1.2 |
0.03 |
0 |
| Trees by diameter class (cm) |
| 7.6-15.2 |
85 |
65 |
23 |
1.5 |
0 |
| 15.2-22.8 |
32.5 |
22 |
8 |
0 |
0 |
| 22.8-38.1 |
3 |
8 |
7 |
0 |
0 |
| 38.1-53.3 |
0 |
3 |
0 |
0 |
0 |
| 53.3-68.6 |
0 |
1 |
0 |
0 |
0 |
| Shrub density (no. stems per ha) |
36,000 |
16,533 |
120,533 |
131,200 |
179,800 |
| Percent ground cover |
77 |
61 |
83 |
61 |
100 |
| Percent canopy cover |
47.5 |
75 |
27 |
5.5 |
0 |
 vegetation height (m) |
9.6 |
15.4 |
5 |
2.7 |
1.8 |
Table 2. Estimated population sizes and breeding densities of bird
families in the Pembina River study area, North Dakota, 1981.
| Family |
Number of species |
Estimated population |
Percent total |
Density pairs per |
| km² |
100 acres |
| Parulidae |
7 |
28,082 |
36.96 |
369.89 |
149.75 |
| Fringillidae |
7 |
17,504 |
23.04 |
230.56 |
93.34 |
| Mimidae |
1 |
5,338 |
7.03 |
70.31 |
28.47 |
| Tyrannidae |
6 |
5,269 |
6.93 |
69.40 |
28.09 |
| Turdidae |
2 |
3,879 |
5.10 |
51.09 |
20.68 |
| Vireonidae |
5 |
3,282 |
4.32 |
43.23 |
17.50 |
| Bombycillidae |
1 |
2,933 |
3.86 |
38.63 |
15.64 |
| Columbidae |
1 |
2,422 |
3.19 |
31.90 |
12.91 |
| Trochilidae |
1 |
1,730 |
2.30 |
22.78 |
9.22 |
| Thraupidae |
1 |
1,550 |
2.04 |
20.41 |
8.26 |
| Icteridae |
3 |
1,451 |
1.91 |
19.11 |
7.73 |
| Paridae |
1 |
1,409 |
1.85 |
18.55 |
7.51 |
| Picidae |
3 |
254 |
0.33 |
3.34 |
1.35 |
| Sittidae |
1 |
243 |
0.32 |
3.20 |
1.29 |
| Corvidae |
3 |
235 |
0.31 |
3.09 |
1.25 |
| Troglodytidae |
1 |
148 |
0.20 |
1.94 |
0.78 |
| Tetraonidae |
1 |
126 |
0.17 |
1.65 |
0.67 |
| Cuculidae |
1 |
71 |
0.09 |
0.93 |
0.38 |
| Hirundinidae |
2 |
30 |
0.03 |
0.39 |
0.16 |
| Accipitridae |
1 |
8 |
0.01 |
0.10 |
0.04 |
| Meleagrididae |
1 |
8 |
0.01 |
0.10 |
0.04 |
| Totals |
50 |
75,972 |
100.00 |
1,000.61 |
405.66 |
Table 3. Estimated populations and mean densities of major breeding
bird species in the Pembina River study area, North Dakota, 1981.
| Species |
Mean density per |
Estimated Population |
Percent total population |
| km² |
100 acres |
| Yellow Warbler |
194.1 |
78.6 |
14,739 |
19.40 |
| American redstart |
105.0 |
42.5 |
7,973 |
10.50 |
| Clay-colored sparrow |
95.2 |
38.5 |
7,226 |
9.51 |
| Gray catbird |
70.3 |
28.5 |
5,338 |
7.03 |
| Veery |
50.9 |
20.6 |
3,867 |
5.09 |
| American goldfinch |
47.3 |
19.1 |
3,591 |
4.73 |
| Common yellowthroat |
47.0 |
19.0 |
3,571 |
4.70 |
| Cedar waxwing |
38.6 |
15.6 |
2,933 |
3.86 |
| Rufous-sided towhee |
33.7 |
13.7 |
2,562 |
3.37 |
| Mourning dove |
31.9 |
12.9 |
2,422 |
3.19 |
| Ruby-throated hummingbird |
22.8 |
9.2 |
1,730 |
2.27 |
| Red-eyed vireo |
22.2 |
8.9 |
1,685 |
2.22 |
| Least flycatcher |
20.7 |
8.4 |
1,572 |
2.10 |
| Scarlet tanager |
20.4 |
8.3 |
1,550 |
2.04 |
| Black-capped chickadee |
18.6 |
7.5 |
1,409 |
1.85 |
| Rose-breasted grosbeak |
18.4 |
7.4 |
1,394 |
1.83 |
| Song sparrow |
16.7 |
6.8 |
1,272 |
1.67 |
| Alder flycatcher |
16.4 |
6.6 |
1,242 |
1.63 |
| Warbling vireo |
16.3 |
6.6 |
1,235 |
1.62 |
| Indigo bunting |
16.0 |
6.5 |
1,213 |
1.60 |
Table 4. Characteristics of breeding bird populations among major forest
habitats, Pembina River study area, North Dakota, 1981.
| Habitat |
Number of species |
Mean density (pairs/km²) |
Species diversity (H') |
| Lowland forest |
32 |
1,311 |
3.647 |
| Quaking aspen |
38 |
723 |
3.641 |
| Willow shrub |
19 |
2,207 |
3.006 |
| Serviceberry thicket |
14 |
807 |
2.936 |
| Bur oak forest |
34 |
847 |
2.866 |
