by Seth Benz and Angi King Johnston
2023 marked the 29th consecutive year of the Cadillac Mountain Hawk Watch in Acadia National Park. The site is the highest elevation on the immediate eastern seaboard and one of the longest running migration monitoring sites in the Northeast. Established as a ranger-led interpretive program in 1995, the count has evolved into a collaboration between the National Park Service, Schoodic Institute’s Bird Ecology Program, Friends of Acadia’s hawk intern sponsorship, and data management services of the Hawk Migration Association of North America (HMANA). All data are accessible here.
This season’s monitoring effort was conducted from August 21 to November 6. Angi King Johnston served as the lead volunteer counter with ample support from a dedicated volunteer crew that included Jim and Kathy Zeman, Chris and Joe Ferrara, Holly and Monty Evans, Anna Durand, and photographer Sandra Mitchell, Acadia National Park rangers Greg Lee and Julia Devalk, and FOA hawk intern Logan Witt. This stellar crew amassed a seasonal observation effort of 235.75 hours over 58 days of coverage. With multiple staff participating on the more promising flight days of the season, the total volunteer and ranger contribution to overall coverage totaled 645.25 hours.
A total of 3,195 migratory hawks were observed resulting in an average of 14 hawks per hour. Both these numbers register above historical averages of 2,867 hawks and 12 hawks per hour, respectively.
This season’s total was driven by 1,271 Broad-winged Hawks, well above the long-term average of 628, and a new record number of 349 Turkey Vultures (average 80). Conversely, American Kestrel numbers were the second-lowest in history with just 282 observations. The lowest American Kestrel count of 262 occurred in 2013 while the highest count of 1,348 was recorded in 2001. Other hawks falling below seasonal average include 119 Osprey (average 148); 707 Sharp-shinned Hawk (995); 8 Cooper’s Hawk (26); and 1 American Goshawk (8).
All other hawks reached their respective historical averages. Special highlights include a Golden Eagle observed in the late afternoon of October 18, the first sighting since 2016, and a season high daily count of 1,382 hawks on September 21, of which 1,137 were Broad-winged Hawks.
Throughout the season the weather was the most notable of factors. Observers experienced daily extended periods of fog through most of October, with warm temperatures near 70 degrees Fahrenheit as late as October 28. The total number of count days were adversely impacted by two remnant hurricanes, Lee and Phillippe, which necessitated securing the site and briefly suspending operations.
The Cadillac Mountain Hawk Watch site is powered by amazing volunteer dedication. Many thanks are due to the regular crew as well as to relative newcomers Bob Duchesne (videography) and Sandra Mitchell (hawk photography). Thanks, too, to the determined cadre of hawk watching visitors, too numerous to name, who are always willing to help with spotting. With this volunteer power, and ongoing interest, the Cadillac Mountain Hawk Watch in Acadia National Park will continue to collect data for park science and provide awe-inspiring encounters with hawk migration.
With the 30th season just ahead, and regional species trends generally understood and ongoing, Schoodic Institute’s Bird Ecology Program will embark upon a deeper analysis of hawk migration data. We look forward to correlating temperature and wind conditions with hawk flight production, and investigating change in species migratory timing, among other topics.
2023 Cadillac Mountain Hawk Watch Species Totals
| Species | 2023 Total | Historical Average | Relative to average |
| Turkey Vulture | 349 | 80 | 4x above! |
| Osprey | 119 | 148 | below |
| Bald Eagle | 132 | 50 | 2x above |
| Northern Harrier | 110 | 101 | above |
| Sharp-shinned Hawk | 707 | 995 | below |
| Cooper’s Hawk | 8 | 26 | below |
| American Goshawk | 1 | 8 | below |
| Red-shouldered Hawk | 2 | 1 | similar |
| Broad-winged Hawk | 1271 | 628 | 2x above |
| Red-tailed Hawk | 38 | 57 | below |
| Rough-legged Hawk | 0 | 0.4 | similar |
| Golden Eagle | 1 | 0.3 | similar |
| American Kestrel | 282 | 587 | below |
| Merlin | 59 | 63 | below |
| Peregrine Falcon | 18 | 20 | similar |
| Unidentified Hawks | 98 | 102 | similar |
Submitted by Seth Benz and Angi King Johnston, January 2024.