Invertebrates are an important dietary component of many grassland birds. Therefore, habitat manipulation aimed at bird conservation should account for changes of invertebrate mass. For 2 consecutive years, we compared the influence of patch-burning, a management practice designed to increase spatial heterogeneity, to no burning on invertebrate mass at 2 spatial scales (pasture and patch). Also, we compared nutritional characteristics of invertebrates taken from burned and unburned patches (within patch-bum pastures). We found patch-burn pastures supported less mass than unburned pastures from the arachnids (P =0.01) early in the growing season in 2000. Total mass and Orthoptera mass differed between burned, unburned and transition patches early in the growing season of 2001. More total mass was collected in 2001 from transition patches than in burned or unburned patches, possibly creating concentration of food resources for grassland birds. In neither year did season of bum influence the invertebrate biomass. We found no evidence that invertebrates were more or less nutritious depending on location of collection.