. The Canadian field-naturalist. 1992 Telfer: Decline of Western Loggerhead Shrike Population 323 Table 3. Habitat at 157 sites Loggerhead Shrike observa- tions in central and south Texas, February 1989. Habitat category Number of observations (Percent) I' IP IIP 95 52 10 61 33 6 'Open, short-grass habitat without trees. -Cropland, brush stands with shortgrass patches, tall forb or grass. ^Largely brush and trees but with mowed highway right-of- way. way right-of-way appeared to provide the foraging habitat. In all habitats utility wires were favoured perches for hunting shrikes. Analysis of s
. The Canadian field-naturalist. 1992 Telfer: Decline of Western Loggerhead Shrike Population 323 Table 3. Habitat at 157 sites Loggerhead Shrike observa- tions in central and south Texas, February 1989. Habitat category Number of observations (Percent) I' IP IIP 95 52 10 61 33 6 'Open, short-grass habitat without trees. -Cropland, brush stands with shortgrass patches, tall forb or grass. ^Largely brush and trees but with mowed highway right-of- way. way right-of-way appeared to provide the foraging habitat. In all habitats utility wires were favoured perches for hunting shrikes. Analysis of shrike habitat use at observation sites both on summer breeding range in Saskatchewan and in Alberta and on probable winter range in south Texas corroborated the many reports that shrikes pre- fer open habitats with short grass as the major feature in their home range during both summer and winter. Land Use Statistics The Canadian census category of "unimproved pasture" was considered to provide a useful index of shrike breeding habitat. Regions which experienced the most severe declines in shrike numbers (as shown by Telfer et al. 1989) had a 39% decline in unimproved pasture between 1946 and 1986 (Figure 1). This compared to a 12% decline in regions that retain substantial numbers of nesting shrikes (south- west and northwest Saskatchewan and southern Alberta as defined by Cadman 1985 and Telfer et al. 1989). Total area of unimproved pasture was also much less in 1986 in the areas with severe declines ( million hectares compared to million hectares in areas retaining substantial populations). In all regions the area of cultivated land (including land in grain and in summer fallow) increased steadi- ly and substantially between 1946 and 1986. On the winter range of Loggerhead Shrikes in Texas the 20 counties in which land use change was studied by lurries (1979) exhibit similiar changes (Figure 2). Only 17% of the region remained in native grassland in 1979 (Fi
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