In the late 19th century bird populations in the United States declined drastically. That was obvious. William T. Hornaday, director of the New York Zoological Park, tried to quantify the bird losses. He published his numbers in 1899. The numbers varied state by state, from a low of 10 percent for Nebraska to a high of 77 percent for Florida. Hornaday estimated that Montana had lost 75 percent of its birds in the previous 15 years.