WHEN DO DIFFERENT RAPTORS PASS BY HAWK HILL?
These graphs show how often a specific raptor has been sighted on any day of the season (normalized as raptors per hour of effort, or RPH). Historically, the peak of "Peak" is September 24th, with an average RPH of 95. Each species (and often age/sex categories within a species) has a unique migration profile which generally lines up with what we expect. Note that abundant species have smoother curves than rare species due to the number of data points available.
INTERPRETING THE GRAPHS
The following graphs show how our raptor sightings per hour (y-axis) break down throughout the year (x-axis), presenting a “migration” (or more appropriately, “raptor activity”) timing profile for each species. Days/hours counted are shown opposite. Note that y-scales are relative and not the same between species.
These graphs were generated in 2016 using all 24 years of GGRO hawkwatch data collected (until 2016) using a regularized quadrant system. View the full report here.