AUTUMN MIGRATION REPORT

SEPTEMBER • Clear skies and overnight northerly winds produced a nice songbird flight on the morning of the 1st; 11 species of warblers were tallied, including 38 Cape May warblers and a season high 20 scarlet tanagers. Ruby-throated hummingbirds also were on the move, with 67 recorded throughout the day.

Light winds, cloudy skies, fog, and rain stalled the raptor flights for the next week, but birds were on the move once the rain cleared. A total of 232 birds were seen on the 9th, including 10 bald eagles, 2 northern harriers, 197 broad-winged hawks, 12 redtailed hawks, 4 American kestrels, 2 merlins, and an early flock of 9 migrating turkey vultures. Another pulse of 235 raptors soared past the lookout on

September 2022

the 10th before rain once again shut down the migration.

A late-day flight of 192 broad-winged hawks between 6 and 7 PM on the 15th was the start of a five-day parade that would total over 10,500 broadwings. Counters tallied 1,536 broadwings on the 16th, but the big push occurred on 17th when volunteer counters Beth Sassaman and Adam Carter recorded 2,883 broadwings. The flight on 18th started slow, and volunteer counters Doug Wood and Caroline Fegley thought the big broadwing flights had passed until the skies opened between 3 and 4 PM. A large kettle of broadwings could be seen over the ridge with birds entering the bottom and exiting out of the top and streams of broadwings passing over the lookout. By the end of the hour a jaw-dropping

1,915 had passed, leaving counters and visitors speechless. The last large broadwing flight occurred the next day when an additional 2,783 broadwings were counted moving ahead of an approaching front. Osprey also took advantage of the strong thermals during those four days; a season high 24 ospreys were tallied on both the 17th and 18th.

Gusty northwest winds greeted me when I arrived on the lookout on the 23rd. The composition of the raptor flight had shifted: migrating sharp-shinned hawks (159) now outnumbered broad-winged hawks (150), and the first big flight of American kestrels occurred with 37. The blustery winds also produced a season high 38 bald eagles, including 22 eagles after 4 PM.

A strong cold front on the 28th produced another pulse of 319 migrants. Senior Scientist JF Therrien recorded 12 bald eagles, 182 sharp-shinned hawks, 23 Cooper’s hawks, 32 broad-winged hawks, 34 red-tailed hawks, 10 American kestrels, 8 merlins, and a season high 6 peregrine falcons. The parade continued the next day with 5 ospreys, 17 bald eagles, 87 sharp-shinned hawks, 17 Cooper’s hawks, 23 broad-winged hawks, 34 red-tailed hawks and the first golden eagle of the season. The 34 redtailed hawks seen both days were unusually high counts for September.

Blue jay numbers started to build during the last week of September. The migrating flocks were eerily quiet in contrast to their often-raucous behavior and could be seen silently flapping past the lookout or flying low through the valleys. A season high of 1,043 jays was counted on the 30th. Also seen on the 30th was the first pine siskin of the season.

BLVU Black Vulture

TUVU Turkey Vulture

OSPR Osprey

BAEA Bald Eagle

NOHA Northern Harrier

SSHA Sharp-shinned Hawk

COHA Cooper’s Hawk

NOGO Northern Goshawk

UNAC Unidentified Accipiter

RSHA Red-shouldered Hawk

BWHA Broad-winged Hawk

RTHA Red-tailed Hawk

RLHA Rough-legged Hawk

UNBU Unidentified Buteo

GOEA Golden Eagle

AMKE American Kestrel

MERL Merlin

PEFA Peregrine Falcon

UNFA Unidentified Falcon

UNRA Unidentified Raptor

OCTOBER • Rain and drizzle cut counts short on the first four days, but once the weather cleared, numbers of sharp-shinned hawks started to build. Accipters were on the move on the 7th, despite the southwest winds. I tallied 130 sharp-shinned hawks, 17 Cooper’s hawks, and an immature northern goshawk, the first of the season. Also seen were season highs of 4 yellow-bellied sapsuckers and 22 red-bellied woodpeckers.

Late in the day, the winds shifted to the northwest, setting up the 8th for one of the best flights of the season with 12 species recorded and season highs for several species. Volunteer counters Scott Morrison, Jon Levin, and Andy Price recorded season highs for sharp-shinned hawk (283), Cooper’s hawk (32), American kestrel (55), merlin (10), and peregrine falcon (6). Strong flights of sharp-shinned hawks continued through the third

October 2022

week with multiple days of triple-digit sharpie counts including 171 on the 15th, 185 on the 18th, 174 on the 20th, and 142 on the 21st.

Most people don’t think of white-breasted nuthatches, a common Pennsylvania breeding resident, as migratory, but we observed whitebreasted nuthatches flying down ridge past the lookout on several days; a season high 11 nuthatches were counted on the 7th, followed by 10 more on 15th.

Numbers of migrating turkey vultures started to build during the end of the first week, starting with a flock of 10 vultures observed on the 5th. Turkey vultures peaked on the 19th, with 66 migrants counted, including a flock of 51 moving through late in the afternoon.

Northwest winds typically produce the best conditions for raptor flights the second half of the season, and the 27th was a prime example. Laurie Goodrich recorded a season high 128 red-tailed hawks soaring on the 8-18 mph winds, along with 63 turkey vultures, 24 bald eagles, 2 sharp-shinned hawks, 10 Cooper’s hawks, 6 red-shouldered hawks, 4 kestrels, and 5 merlins. Laurie also tallied two red bats flapping past the lookout.

A flock of five evening grosbeaks were spotted on the 31st, the season’s first sighting of this irruptive winter finch. Other winter finches spotted on the 31st included 22 purple finches and 12 pine siskins.

NOVEMBER • Volunteer counters Rob Feldman and Karen Lutz started off November on a high note with 13 bald eagles and a golden eagle recorded on the 1st, but unseasonably warm temperatures and light winds during the first week slowed the golden eagle flight. Only seven goldens were counted during what is typically their peak migration period. Nonetheless, a very late osprey was observed on the 4th and migrating monarch butterflies were recorded on both the 4th and the 5th.

Sightings of irruptive winter finches continued in November with the first crossbills of the season: a red crossbill on the 5th and a flock of seven whitewinged crossbills on the 9th. Season high

November 2022

counts of 58 purple finches were tallied on the 6th, 23 evening grosbeaks on the 23rd, and 26 pine siskins on the 26th.

Flights of red-tailed hawks remained steady but in low numbers through November. Research Biologist Rebecca McCabe and former trainee Marzia Verduci tallied 55 red-tailed hawks on the 7th, but the high redtail day of the month was on the 13th. Volunteer counters Jeremy Scheivert and Doug Wood counted 56 redtails along with 24 bald eagles, 2 northern goshawks, 6 red-shouldered hawks, and a season high 10 golden eagles.

Volunteer counters Caroline Fegley and Scott Morrison braved the single-digit wind chills on the 20th and were rewarded with excellent looks at migrating eagles; 11 bald and 7 golden eagles were observed along with 3 northern harriers, 29 red-tailed hawks, and 2 merlins. Several large flocks of migrating gulls were also observed on the 20th—ring-billed gulls were the most common, but Caroline and Scott also recorded several herring and Bonarparte’s gulls as well.

Bracken Brown recorded 11 bald eagles soaring together in a thermal on the 28th, and by day’s end he tallied a total of 24 bald and 10 golden eagles. Murders of migrating crows were also observed on the 28th, with a season high 428 counted.

DECEMBER • The strong eagle flights continued in December with 19 bald eagles and 6 golden eagles on the 1st. Laurie Goodrich tallied 32 birds on the 8th, the last big count of the season that included 9 black vultures, 17 bald eagles, 5 red-tailed hawks, and 1 golden eagle.

Waterfowl migration was light for most of the fall, perhaps due to the warmer than average November, but geese were moving “en masse” from the 3rd through the 8th. A total of 6,647 snow geese and 7,836 Canada geese were tallied those days, with a high of 3,871 snow geese on the 10th and 3,748 on the 12th.

The last official count day on the 15th was cancelled due to rain, but on the 14th, volunteer counter Matt Wlasniewski had a stellar late-season day with two bald and six golden eagles, and a subadult golden eagle was the last bird of the official count season. Matt also counted two common redpolls, the only redpolls on this year’s count.

Counters couldn’t resist heading to North Lookout on cold, windy days after the official count ended, and they were rewarded for their perseverance. Twenty birds were observed after the official count ended during seven hours of observation over three days. Bracken Brown observed two golden eagles and two adult abieticola red-tailed hawks on the 18th. The abieticola redtails are

December 2022

Other Migrants of Note • Autumn 2022

MIGRATION SUMMARY • In every season there are going to be winners and losers—counts of some species will be above average while others will be below average. Unfortunately, there were not a lot of winners this year. The big winners were broadwinged hawks, as their count of 12,503 was the ninth highest count in Hawk Mountain’s 88-year count history. The other big winner was bald eagles; while not a record setting year, the 591 total was a close second, and the peak day of 38 balds was the fourth highest single-day count.

Nine of 15 species had below average counts; most notable were northern goshawk, 71% below average, osprey, 33% below average, red-tailed hawk and golden eagle, both 21% below average, and northern harrier, 16% below average. The red-tailed hawk total of 1,296 was the third lowest count recorded at the Sanctuary. Hawk Mountain was not the only watchsite in Pennsylvania that experienced a below average flight this year— northern goshawks and ospreys were below average at all watchsites in the state. However, there was some variation among sites: golden eagle and red-tailed hawk flights were below average at eastern Pennsylvania watchsites, while central and western Pennsylvania watchsites had above average counts. The low count for golden eagles could be due to wind conditions during late October and early November when winds were often light and out of the east and southwest, ideal conditions for a site like Allegheny Front in western Pennsylvania, but poor conditions for Hawk Mountain.

For osprey, northern harrier, and red-tailed hawk, this year’s counts are a continuation of their long-

2022 Autumn Migration Summary

term declines in numbers at Hawk Mountain. The causes for these declines vary among species. For northern harriers, it is likely loss of native grasslands that they use for breeding; for osprey, it may be the increase in the bald eagle population; for red-tailed hawks, it could be due to global climate change with increasing temperatures changing their migratory habits.

For species that had average counts this year, such as sharp-shinned hawks and American kestrels, we shouldn’t be complacent thinking everything is okay, because one year’s worth of data doesn’t tell the whole story. If we look at the trends for the last 10 years, we see that counts of both species are declining at the rate of 5-6% per year. The cause(s) of these declines have yet to be determined, but we hope to find out in the near future. For more information on count trends of your favorite species at Hawk Mountain, visit the Raptor Population Index website at rpi-project.com.

Hawk Mountain counters also tallied 70,019 nonraptors, including 1,663 butterflies, 581 dragonflies, and 2 mammals. The most abundant non-raptor was Canada goose with 14,164 counted, followed by snow goose (6,724), blue jay (5,719), common grackle (5,097), and cedar waxwing (5,003). Morning songbird flight numbers seemed low overall. Warbler diversity was high with 23 species recorded, but there were few days with large quantities counted. Winter finches were present in good numbers, with counts of purple finch (679), red crossbill (62), and evening grosbeak (68) all above average. In addition, quite a few uncommon non-raptors were observed this fall, including cackling goose, lesser yellowlegs, Bonaparte’s gull, sandhill crane, brown thrasher, yellow-throated warbler, and dickcissel.