The Northern Harrier
count for the 2011 season is 19% below the 10 year average and
29% below the average since 1985. The trend
line shows a decrease of almost 3 Harriers per year, over the
41 years, for a net loss of 111. This
suggests that we are counting 111 fewer Harriers on
average than we counted at Hook in those early years,
beginning in 1971.
The trend lines have not been tested
for significance. Their intent is to provide an overview of the general
trend. The graphs show two trend lines: 1971 - present,
and the last 10 years. The Hook Mountain Hawk Watch began in 1971, and
the points with blue markers indicate the totals for all these years.
The points that show red squares around the blue markers represent the
last ten years, showing the trend in this last decade.
more about trend lines. . . .