Northern Prairie Wildlife Research Center
The nesting habitat most preferred by gadwalls also was Brush; Odd area was second, and lowest preference was for Cropland, Grass, and Wetland (Table 6). In parkland, we estimated that 79% of gadwall nests were in Odd area; in prairie, their nests were in relatively similar proportions in Brush (49%) and Odd area (41%) (Table 7).
Blue-winged teals preferred mostly to nest in Right-of-way; Brush was second, followed closely by Odd area and Grass (Table 6). Cropland was least preferred as nesting habitat by blue-winged teals. In parkland, we estimated that nests were initiated by blue-winged teals in relatively similar proportions in Grass (37%) and Odd area (33%); in prairie, 46% of their nests were in Grass and 29% were in Right-of-way (Table 7).
Odd area and Hayland were both ranked high in preference for nesting by northern shovelers; Wetland was third, and lowest preference was for Cropland and Woodland (Table 6). In parkland, we estimated that 44% of northern shoveler nests were in Odd area and 31% were in Grass; in prairie, 45% of their nests were in Grass and 23% were in Odd area (Table 7). Nearly all nesting in Wetland by northern shovelers was in dry wetland basins (Table 8).
Preferences for nesting habitat by northern pintails were similar to those of mallards, except that Cropland was ranked third (Table 6). In parkland, we estimated that 34% of northern pintail nests were in Cropland and 27% were in Right-of-way; in prairie, 45% of their nests were in Cropland and 31% were in Brush (Table 7).
|Habitat||Probability (%) of selection|
|Class||% availableb||Mallard||Gadwall||Blue-winged teal||Northern shoveler||Northern pintail|
|aAn average of
50% of landscape in all area-years was classified as Unsuitable (included
area originally classified as Barren plus area of Cropland
that was cultivated before early May and area of Wetland that was open
water in early May or contained sparse emergent nesting cover)
and not available as nesting cover.
bAvailability is based on Table 2.
cOdd area included patches of cover <2ha in size and an array of features usually found in Cropland (e.g., rock piles, gravel borrow pits, narrow borders of upland vegetation around Wetland and along fences between areas of Cropland).
|Species||Nest initiations (%)|
|Cropland||Grass||Brush||Wetland||Hayland||Woodland||Right-of- way||Odd area|
|aNumbers of nests
initiated annually in each habitat were estimated as the product of habitat
composition and species preference for nesting in a habitat
(Table 6), weighted by number of breeding pairs on the study area.
bRefers to 1 area studied for 1 year.
cArea-years reduced by 2 because breeding pairs were not detected on all areas each year.
dArea-years reduced by 1 because breeding pairs were not detected on all areas each year.
|Species||n||Frequency of locations|
|aIncludes 2 cinnamon teal.|