The population has been estimated at between 5,000 and 10,000 adult birds, although those numbers have recently been revised to the range of 11,000 to 14,000, with a total population estimate of about 15,000 to 20,000. In March 2009, a multi-agency report, the first of its kind, issued by the Cornell University Lab of Ornithology in conjunction with federal agencies and other organizations, indicated that the mountain plover is one of the birds showing serious declines in population. The population of mountain plovers is in decline because of cultivation, urbanization, and over-grazing of their living space.