Geroge, A. D., T. J. O'Connell, K. R. Hickman, and D. M. Leslie, Jr. 2009. Influence of Old World bluestem (Bothriochloa ischaemum) monocultures on breeding density of three grassland songbirds in Oklahoma. Proceedings of the Fourth International Partners in Flight Conference 4:691-697.
Despite persistent and widespread declines of grassland birds in North America, few studies have assessed differences between native grasslands and seeded monocultures as songbird habitat. In the Great Plains, many fi elds enrolled in the Conservation Reserve Program have been seeded to Old World bluestems (OWB), but there is evidence to suggest that OWB may not provide suitable conditions for several grassland bird species. Our objectives were to investigate the infl uence of OWB monocultures on vegetation structure, composition, and breeding densities of three common grassland bird species. In 2007, we used distance sampling to survey breeding songbirds in 6 native mixed grass prairie and 6 OWB fi elds in Garfi eld, Grant, and Alfalfa counties, Oklahoma. Native mixed grass prairie supported taller and denser vegetation, as well as greater forb cover than OWB fi elds. Breeding density of Grasshopper Sparrow (Ammodramus savannarum) was higher in OWB monocultures, while density of Dickcissel (Spiza americana) and Eastern Meadowlark (Sturnella magna) was similar among fi eld types.