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Grassland bird populations have declined more than any other guild of birds during the past 50 years as a result of habitat loss. The majority of remaining native grassland habitat in North America is managed for livestock production, so livestock grazing management can have significant impacts on the conservation of grassland birds. We evaluated the effects of three livestock grazing systems on grassland bird abundance in the northern mixed-grass prairie ecosystem of eastern Montana. Our objectives were to: 1) evaluate effects of grazing system on species-specific abundance of grassland birds, 2) evaluate the importance of local vegetation characteristics for grassland birds within grazing systems, and 3) provide management recommendations to agencies and private landowners for improving habitat quality for grassland birds in the northern mixed-grass prairie. During 2016�17, we conducted replicated point-count surveys at 150 locations on a 3,008-ha ranch managed with rest-rotation cattle grazing, and 155 locations on adjacent reference properties (4,020-ha) employing season-long or intensive summer-rotational grazing systems. We evaluated a suite of habitat conditions within 100-m from each survey point. We built and analyzed support for a set of N-mixture models to identify grazing system influences on grassland bird abundances while controlling for local habitat conditions at each site. Relative to season-long and summer-rotational grazing systems, we observed a lower abundance of a dense-grass obligate species, the grasshopper sparrow (Ammodramus savannarum; �? = -0.30 � 0.05), on pastures within rest-rotation grazing systems. Additionally, we found evidence of an interaction between grazing system and rangeland productivity, where areas of high productivity had higher abundance estimates of grasshopper sparrow on pastures employing intensive summer-rotation grazing ( �? = 0.55 � 0.06), and lower abundance estimates of grasshopper sparrow on pastures employing rest-rotation grazing ( �? = 0.34 � 0.04),� or season-long grazing ( �? = 0.31 � 0.06).