Developing Spatially Explicit Habitat Models for Grassland Bird Conservation Planning in the Prairie Pothole Region of North Dakota

Conservation planning for birds is increasingly focused on landscapes. However, little spatially explicit information is available to guide landscape-level conservation planning for many species of birds. We used georeferenced 1995 Breeding Bird Survey (BBS) data in conjunction with land-cover information to develop a spatially explicit habitat model predicting the occurrence of Northern Harrier (Circus cyaneus) in the Prairie Pothole Region of North Dakota, USA. Presence of Northern Harriers was positively associated with the amount of grassland in the landscape and presence of Northern Harriers at adjacent stops, and negatively associated with forest cover and an eastern geographic gradient. The resulting spatially explicit map showing predicted presence of Northern Harrier corresponded well with results of a conceptual grassland bird habitat model applied to the same landscape. Detections of Northern Harrier in 1997 BBS data used for validation were strongly correlated with model predictions. Our findings indicate that empirical models using BBS data and conceptual models can be used in conjunction with landcover data to develop spatially explicit models predicting general suitability of landscapes for some species of birds.