Northern Prairie Wildlife Research Center
Among the typical shrub species, chokecherry (Prunus virginiana) and juneberry (Amelanchier alnifolia) were the most frequent. In combination, these species were recorded at one-third of the vegetation sample points. The importance values (Curtis and McIntosh 1951) suggest that chokecherry and hawthorn (Crataegus sp. ) were surprisingly similar in importance. Chokecherry exhibited the greatest importance value in 12 wooded draws, hawthorn in 9 draws, juneberry in 7, and bullberry (Shepherdia argentea) in 1. Greatest values were identical for juneberry and hawthorn in one draw.
Forty-seven bird species were recorded from the 30 wooded draws. Twenty-three additional species were recorded in adjacent draws or in native or man-made habitats near the censused draws. The observed total of bird species was about 34 % of the known nesting avifauna of North Dakota (Faanes and Stewart 1982). The most frequently occurring species were rufous-sided towhee, brown-headed cowbird, house wren, and American goldfinch.
The richness of the avifauna of western North Dakota wooded draws is exemplified by the diverse mixture of typically eastern and western bird species nesting in proximity to each other. Of particular interest to the avian ecologist are the patterns of distribution of wooded draw breeding bird species during the non-nesting season. Among the 47 species occupying wooded draws, 22 (47%) are neotropical migrants, 20 (43 %) migrate to warmer climates in the southern United States and Mexico, and 5 are permanent residents or winter vagrants on the northern Great Plains.
Much useful information remains to be gathered on breeding bird populations and their interactions with vegetation features of wooded draws in western North Dakota and adjacent eastern Montana