Waterfowl Communities in the Northern Plains

Table 2

Table 2. Average number, standard deviation, and coefficient of variation of indicated breeding pairs of ducks on Woodworth Study Area, 1965-89, and trends (correlation with year) for counts and Woodworth and continental indices.

_____________________________________________________________________________

                                                             Trend
                                   Standard           _____________________ 
      Species             Average  deviation   CV     Woodworth   Continent
_____________________________________________________________________________

Dabbling ducks
  Mallard                  52.24     12.44     23.8     -0.09      -0.48**
  Gadwall                  63.56     17.30     27.2     -0.41**    -0.28
  American Wigeon           9.52      4.01     42.1     -0.59***   -0.30
  Green-winged Teal         7.72      4.08     52.8     -0.65***    0.26
  Blue-winged Teal        211.36     85.70     40.5     -0.32      -0.22
  Northern Shoveler        30.28     13.47     44.5     -0.02      -0.16
  Northern Pintail         27.44     12.09     44.1     -0.51***   -0.67***
Diving ducks
  Redhead                  25.76     17.84     69.3      0.63***   -0.23
  Canvasback                9.68      7.72     79.7      0.58***   -0.29
  Lesser Scaup             29.72     13.01     43.8      0.65***    0.10
Stiff-tail duck
  Ruddy Duck               24.84     19.78     79.6      0.37*      0.41**
_____________________________________________________________________________
*P < 0.10
**P < 0.05
***P < 0.01

Previous Section -- Table 1
Return to Contents
Next Section -- Table 3