Cost-share conservation practices have mixed effects on priority grassland and shrubland breeding bird occupancy in the Central Hardwoods Bird Conservation Region, USA

Abstract

Globally, agricultural ecosystems continue to be the most imperiled for biodiversity. Subsequently, countries focused on cost-share conservation programs whereby private landowners are paid to conserve or restore their land. In the United States, populations of grassland and shrubland breeding birds continue to decline, despite state, federal, and private cost-share conservation programs. We related avian occupancy to cost-share conservation programs across the Central Hardwoods Bird Conservation Region using spatially explicit patch-scale survey data. Once per year from 2008 to 2012, we surveyed 5303 discreet points for 9 grassland and shrubland breeding bird species using roadside 5-min point-count surveys in 37 counties across 7 states. We modeled point-specific land cover and heterogeneity in conjunction with cost-share conservation program information using a multi-season robust-design occupancy model. Land-cover covariates were most important in models for species occupancy. For every species except Bell's vireo (Vireo bellii), Field sparrow (Spizella pusilla), and Prairie warbler (Setophaga discolor), addition of conservation covariates to best-supported land-cover models improved occupancy model fit, though effects of conservation programs on occupancy were mixed. Eastern meadowlark occupancy was negatively correlated to the presence of conservation. Alternatively, Northern bobwhite (Colinus virginianus) occupancy was 200% greater when a conservation practice was at a point rather than being located 4 km away. If cost-share conservation is going to reverse biodiversity declines in agricultural ecosystems, then scale-appropriate models will need to be used to prioritize future implementation because the status quo provides limited mixed effects on grassland and shrubland bird species occupancy.