||No published data exist on responses of grassland passerines and their habitat to combined grazing and burning treatments in northern mixed-grass prairie. At Lostwood National Wildlife Refuge (LNWR) in northwestern North Dakota, we monitored breeding bird occurrence, abundance, and habitat during successive annual grazing treatments
(1998–2000) on 5 prescribe-burned, mixed-grass prairie management units (range = 50–534 ha, each burned 3–6 times in the previous 10–20 years). All breeding passerine species characteristic of upland, northern mixed-grass prairie were common (>10% occurrence) during at least 1 of 3 years on burned and grazed units, except Chestnut-collared Longspur (Calcarius ornatus), which was uncommon. Vegetation was generally shorter and sparser than that found on 4 nearby units treated by fire only (1999; density, visual obstruction, and height, all P < 0.01). Regardless, occurrences of individual bird species resembled those previously documented on prairie units at LNWR with similar fire histories but no grazing; however, Brown-headed Cowbird (Molothrus ater) occurred 2.4 times more frequently on burned and
grazed units studied. Our data suggest that species diversity of breeding grassland passerines changes little during initial
years of rotation grazing at moderate stocking rates in fire-managed, northern mixed-grass prairie at LNWR.