HABITAT SELECTION BY CATTLE ALONG AN EPHEMERAL CHANNEL

Because of widespread concern about cattle grazing effects on riparian zones of public lands, seasonal habitat selection by cattle was studied along a cold desert area ephemeral waterway of north-central Wyoming. Little is known of grazing effects on ephemeral streams compared to perennial streams. Cattle activity was monitored in small pastures and a surrounding large allotment in spring, summer, and fall. Observations included activity and habitat where it occurred. Concomitantly, utilization levels, protein content, and dry matter content of forages were determined in the small pastures. A higher percent of cattle selected channel and floodplain habitats than percent area of habitats while a lower percent of cattle selected upland habitat than percent of this habitat in the area. Utilization levels of forages except greasewood (Sarcobatus vermiculatus (Hook.) Torrey) in the floodplain were not greatly different among habitats. Protein and dry matter content of forages did not vary greatly among habitats, except greasewood had higher protein and lower dry matter than other species and received much higher use. Forage quality declined in summer and fall. Animal preference for channel habitat was attributed to more available forage in the channels. In contrast, selection of floodplains was due to succulence and high protein content of greasewood. Comparison of cattle selectivity between small pastures ard the large allotment indicates that greater avoidance of upland areas by cattle is likely due to greater distances to drinking water in the large allotment.