A Model of the Productivity of the Northern Pintail
Figures
 |
Fig. 1. Relation between estimated nest
initiations per pair ( i
) of northern pintails and mallards (Anas platyrhynchos) and
percentage of wetlands containing water in mid-June (PW) at the Woodworth
study area, Stutsman County, North Dakota, 1966-81. |
 |
| Fig. 2. Percentage of northern pintail
(Anas acuta) nest site visual obstruction measurements (VOMs)
and percentage of field transect VOMs by vegetative height class in
the Koenig study area, McLean County, North Dakota, 1981. |
 |
| Fig. 3. Percentage of northern pintail
and mallard nests in each visual obstruction measurement (VOM) class
in the Woodworth study area, Koenig study area, and Central Grasslands
Research Station, Stutsman and Kidder counties, North Dakota, 1975-86. |
 |
| Fig. 4. Regression of the nest site
attractiveness index (A) of northern pintails and mallards on visual
obstruction measurements (VOMs) in the Woodworth study area, Koenig
study area, and Central Grasslands Research Station, North Dakota, 1975-86. |
