The northern pintail’s North American population has been in a tailspin since the late 1950s

In North America, the northern pintail Anas acuta breeds from the prairie pothole region of the Upper Midwest across Canada and Alaska. The northern pintail’s North American population has been in a tailspin since the late 1950s. Numbers have dropped from an estimated 10 million in 1957 to around 3 million today. Loss of habitat and changes in agriculture appear to be the most serious threats to North American pintails.

Source: Smoky Mountain News, 18 January 2012
http://www.smokymountainnews.com/news/item/6042-northern-pintail