The Northern Harrier
count for the 2019 season is 67% below the 10 year average and
77% below the long term average since 1971. The trend
line shows a decrease of almost 3 Harriers per year, over the
49 years, for a net loss of about 135. This
suggests that we are counting 135 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. . . .