The geographic pattern of species richness for ground and low-nesting birds is similar to that exhibited by all species. The number of species is largest from New England and the Maritime Provinces across the northern Great Lakes and into central Canada. Species richness is lowest in the southwestern deserts and along the western Great Plains.
Negative trends prevail from the Rocky Mountains eastward, but are also predominant in the Great Basin region and along the Pacific coast from California north into British Columbia. Increases are most prevalent in the southwestern states, especially Arizona and New Mexico, and also in the Rocky Mountains of Canada.
For ground and low-nesting birds, the low percentage of species with positive trends (34%) reflects that many species are associated with grassland and scrub/successional habitats, the two habitat groups with large percentages of declining species. The prevalence of declining trends in eastern and central North America are also a result of the predominance of species from these two habitat groups. West of the Rocky Mountains, the geographic pattern of increases and declines is similar to that shown by the scrub/successional group.