Table 6. Percentage overestimate (positive values) or underestimate (negative values) of the total population sizes of five avian species of management interest by estimates made in roadside buffers in five years.
|
|
|
|
Species |
|
|
|
Buffer width |
Year |
Eastern Towhee (Pipilo
erythrophthalmus) |
European Starling (Sturnus vulgaris) |
Kentucky Warbler (Oporornis formosus) |
Prairie Warbler (Dendroica discolor) |
Wood Thrush (Hylocichla mustelina) |
|
50 m |
1980 |
36.7 |
223.5 |
–10.7 |
–15.8 |
1.7 |
1990 |
65.7 |
265.7 |
–15.8 |
–18.4 |
2.5 |
1997 |
45.7 |
171.4 |
–15.1 |
–24.5 |
3.5 |
2000 |
15.9 |
164.9 |
–12.3 |
–38.4 |
5.0 |
2003 |
9.9 |
137.4 |
–12.6 |
–41.8 |
6.5 |
200 m |
1980 |
22.1 |
129.4 |
–5.5 |
–11.8 |
2.3 |
1990 |
44.3 |
188.7 |
–10.3 |
–25.6 |
3.2 |
1997 |
33.3 |
117.4 |
–9.8 |
–17.5 |
3.7 |
2000 |
9.3 |
112.2 |
–7.2 |
–30.4 |
5.0 |
2003 |
2.1 |
92.9 |
–6.5 |
–37.0 |
6.4 |
400 m |
1980 |
7.3 |
64.2 |
–2.1 |
–11.7 |
1.8 |
1990 |
15.3 |
96.3 |
–3.9 |
–32.2 |
3.6 |
1997 |
18.8 |
76.0 |
–5.8 |
–17.5 |
3.3 |
2000 |
2.4 |
71.8 |
–3.3 |
–26.0 |
4.6 |
2003 |
–2.7 |
60.2 |
–2.4 |
–30.9 |
5.9 |
|
|
|