The Illinois Ornithological Records Committee (IORC) recently concluded evaluations of 15 records of occurrence of rare birds in Illinois, accepting 11 and not accepting four. For each record, we indicate below the species or form, with number of individuals in parentheses if greater than one, followed by date or date range, location, and county. At the end, the record number is indicated in parentheses, followed by, for accepted records, names of the documenters. IORC thanks all the documenters, for accepted and unaccepted records alike, for their submissions. All documentation is maintained in the IORC archives so that there is a permanent record of all these observations. Documentation, regardless of the Committee’s decision, is a valuable part of the record of bird life in Illinois.
Records Accepted
Black-bellied Whistling-Duck, 22 July 2017, Army Depot Road, Carroll County (2017-028; Dan Williams)
Black-bellied Whistling-Duck, 7 August 2017, Zuma Creek flats, Rock Island County (2017-033; Steve Freed)
White-winged Dove, 17 May 2016, Chicago, Cook County (2016-100; David Mroczkowski)
White-winged Dove, 9 July to 26 August 2017, Kaneville, Kane County (2017-026; Marion Miller, Vince Moxon, Dan Williams)
Ruff, 20-21 August 2017, Emiquon National Wildlife Refuge, Fulton County (2017-035; Matthew Cvetas, Bob Fisher)
Little Gull, 20-21 April 2016, Lake Springfield, Sangamon County (2016-101; H. David Bohlen)
Wood Stork, 6-20 July 2017, Rend Lake, Jefferson County (2017-024; C. Leroy Harrison, Dan Kassebaum, Dan Williams)
Wood Stork, 5 August 2017, Sexton Creek wetlands, Alexander County (2017-032; Allen Gathman)
Neotropic Cormorant, 28 March 2017, Pontiac, Livingston County (2017-009; Demetri Lafkas)
Neotropic Cormorant; 4 August 2017, Lake Shelbyville, Moultrie County (2017-031; Ron Bradley)
White Ibis, 9-20 July 2017, Grand Tower Township, Jackson County (2017-025; Whitney Gregge, Dan Kassebaum)
Records Not Accepted
Black Rail, 10 May 2010, Worship Trail, Cook County (2010-031)
Royal Tern, 8 May 2017, Channahon Township, Will County (2017-027)
Great Blue Heron (white form), 12 July 2017, Savoy, Champaign County (2017-029)
Say’s Phoebe, 7 August 2017, Cape Bend wetlands, Alexander County (2017-034)
Golden Eagles (like this juvenile) have wings that pinch in to the body with bulging secondaries that taper to the hands
As November rolls in, many Illinois birders shift their focus to a shorter list of target species. The majority of migrants have left the state for the winter, but some are still moving in. November brings to mind the first big push of waterfowl, and the search for vagrants. At Illinois hawkwatch sites, November can hold some late-fall specialties that get many people bundled up to stare down a Northwest wind!
My favorite of those specialties is the Golden Eagle. At sites along the Lake Michigan shoreline, such as the Illinois Beach State Park Hawkwatch, and Fort Sheridan Hawkwatch, Golden Eagles are an uncommon, but regular migrant with seasonal averages being under five. At a more inland site like DuPage County’s Greene Valley Hawkwatch, Golden Eagles are still uncommon, but the seasonal average increases to seven. Although the averages are different, there is a common thread between both inland and shoreline sites, and that is that many of the Golden Eagles do not come in for close views! With Bald Eagles being a much more common migrant, it is important to learn how to differentiate the two species at a distance. Luckily, by using shape and flight style, the two can be separated even when plumage details are not useful for identification.
Shape
One difference between the two eagle species is the size of the head and length/shape of the tail. On a Bald Eagle, the head is large and bulbous, protruding far beyond the leading edge of the wings. At most angles, the bulky head of a Bald Eagle is obvious. Bald Eagles also have broad tails that are short relative to their size. At times, it can appear as if the head is only just shorter in length than the tail.
Note the broader wings, broad tail and straight trailing edge of this juvenile Bald Eagle
In comparison, Golden Eagles have much smaller heads. The head on a Golden Eagle is almost buteo-like and is not prominent, especially on distant birds. With Golden Eagles, the tail is longer and skinnier than that of a Bald Eagle. Be cautious with the tail, as both species can have a short-tailed impression when the tail is fully fanned during a soar.
Another difference is in wing shape. Bald Eagles have very broad wings. On the trailing edge, the wings look nearly the same in length from the body to the outer primaries. This gives the impression of an almost straight line from the body all the way to the outer primaries when they soar. Many hawkwatchers describe the shape as to two large planks sticking out from the body. At almost all angles, a Bald Eagle’s wings will look massive from body to wingtip.
On a Golden Eagle there’s more curve to the trailing edge. The secondaries on a Golden have a distinct bulge before reaching the shorter outer primaries (or hands), which is reminiscent of a buteo. Also, the shorter inner secondaries pinch in towards the body. This gives a Golden Eagle an “S” curve profile to the trailing edge of the wing. At certain angles, the wings can almost look paddle-like, something you will not see on a distant Bald Eagle. Overall, the impression of a Golden Eagle is slimmer than that of a Bald.
Flight
The curved trailing edge becomes more obvious on this distant adult Golden Eagle
Bald Eagles tend to soar on flat wings. They make long, lazy circles, taking what seems like a decade to pass by once detected over the horizon! Bald Eagles tend to glide on drooped wings and overall look very bulky. In a glide, the large head and short tail are still obvious. Another thing to look for is how the eagle is flapping. With a Bald Eagle, the flaps are deep and strong. A key difference between the two species is how they set their wings after flapping. A Bald Eagle, when setting their wings to soar/glide, will go through a large upstroke and adjust back to their flat-winged position.
Golden Eagles soar with an obvious dihedral and glide on bowed wings or with a modified dihedral. They are also strong fliers, and only the toughest winds will allow for occasional unsteadiness as they pass by. This is why distant Turkey Vultures (small head, long tail and dihedral) can sometimes be confused for Golden Eagles. With a Golden, the flap is shallower and smoother than that of a Bald. A Golden Eagle will set their wings at the top the upstroke, looking like they’ve snapped their wings into place above the body in a dihedral.
Summary
Distance does not hide the bulky, straight wings of this Bald Eagle
Although close eagles allow for study of plumage differences, we often aren’t given that luxury. With practice, some distant eagles can be identified. In fact, many of the field marks mentioned become more obvious at a distance! This is especially true with the trailing edge of the Golden Eagle’s wings, and the large head of a Bald Eagle. If you find a distant eagle this November, don’t put your binoculars down or take your eyes off of the scope! Spend some time with it, make some mental notes about the eagle’s shape, and flight style.
I would also highly encourage anyone interested in learning more about raptor ID to visit an Illinois hawkwatch site. Gaining field experience alongside veteran hawkwatchers is the best way to improve raptor identification, especially with distant birds. So throw on your layers, everyone, and get out there!
IOS has created a Christmas Bird Count (CBC) map so you can easily find count circles near you. Click on each circle to find the date of the count and contact information. If you have updates for a count, use the Contact Us form and direct your message to “Christmas Bird Counts.”
Glossy/White-faced Ibis: McHenry (North) – Up to nine dark ibis were present at Glacial Park Conservation Area in McHenry County for several weeks in October. Only one, perhaps two individuals have been positively identified as White-faced Ibis.
Glossy/White-faced Ibis: Cook (North) – On October 21st, Josh Engel found a juvenile dark ibis at Hegewisch Marsh in Chicago, Cook County.
Black Vulture: McHenry (North) – On October 19th, two Black Vultures were photographed by Suzanne Bidgood at Glacial Park Conservation Area in McHenry County.
Black Vulture: Lake (North) – On October 17th, a Black Vulture flew over the Ft. Sheridan hawk watch and was photographed by Karen Lund.