HAPET Breeding Pairs - Horned lark

Estimated number of breeding pairs of Horned lark based on the amount of grass, trees, and/or hay in the landscape. Landscape scale varied from 1/4- to 2-mile radius depending on the species. Pair estimates were calculated for grass patches >=1 ha, extrapolated to 40-ac cells, then smoothed by averaging over a 1-mile radius. Models were based on point count surveys conducted in 2003-2005 throughout the Tallgrass Prairie Pothole Region. Point count locations were stratified by cover type, the amount of grass in the landscape, and USFWS Wetland Management District boundaries. Landcover data were derived from 2000 Thematic Mapper imagery. Grid values = number of breeding pairs per 30-m pixel.