Northern Prairie Wildlife Research Center
|Habitat at nest||Percent use||Available habitat (%)||Preference ranka|
|200-m circle||Study area||200-m circle||Study area|
|Grassland||40.1||42.2||37.9||5 B||5 B|
|Wetland||16.2||13.2||14.8||3 B||4 B|
|Odd area||15.5||3.1||2.4||1 A||2 A|
|Right-of-way||14.1||4.3||1.3||2 AB||1 A|
|Hayland||12.0||11.7||5.1||4 B||3 B|
|Cropland||2.1||25.4||38.3||6 B||6 B|
|aHabitats with different letter symbols are significantly different (P < 0.05).|
Under these definitions there are 2 possible comparisons of use and availability. Significance was tested by a multiple comparison, extending the method of Neu et al. (1974). Tests were applied to differences among relative preferences.
The relative preferences for habitats presented in Table 8 show that right-of-way and odd areas rank at the top in preference and cropland ranks at the bottom. The other types fall between these extremes, but our sample is not large enough to produce a consistent ranking pattern.
The results obtained from this type of analysis are, in part, a function of the habitat classification used. This problem is apparent in our data where grassland was used in about the same proportion as its availability. The plant community of grassland is diverse, and it is possible that birds selected a component of grassland. To test this hypothesis, we subdivided the area originally mapped as grassland in the 200-m-radius circle into grass and brush components. This new analysis of 7 classes showed a significant preference for brush and rejection of grass. The relative rank of brush was significantly lower than odd area and higher than grass and cropland. It did not differ from right-of-way, wetland, and hayland. Similar selection of 1 part of other classes such as wetland also may occur, but we were unable to test these because of problems in photointerpreting the available habitat.