NOTE: This is a work in progress, an essay that I do not expect to complete for a month or more. If you are reading this before February 2026, please return later to see the finished product. If you are reading this after January 2025 and this note is still here, then I have not yet completed it.
Within the non-Hawaii portion of the ABA Area, two identification quandaries perplex more birders than any others, causing or enabling more misidentifications in eBird photos than any others, at least in my extensive experience as an eBird reviewer and as an inveterate reviewer of eBird photo identifications. The first is Greater Scaup versus Lesser Scaup, on which quandary I have written thrice:
1: Beginning on page 75 here;
2: About a single interesting scaup here; and
3: Most recently, in the July 2025 issue of Birding, a 3000-word piece primarily on various aspects of the heads of the two species (behind a paywall).
The current essay treats the other huge identification pitfall: the Sharp-shinned Hawk (Accipiter striatus) versus the Cooper's Hawk (Astur cooperii). Near the end, I also treat, rather cursorily, the distinction of juveniles of Cooper's Hawk and American Goshawk (Astur atricapillus).
I first must note that the ABA Area now hosts only one member of Accipiter, the Sharp-shinned Hawk; the other two have been moved to Astur, a genus originally proposed for what we now know as the Eurasian Goshawk (A. gentilis). Yes, that means that Cooper's Hawk is more closely related to American Goshawk than it is to Sharp-shinned Hawk, a feature known well before the split of Accipiter.
With the recent major reshuffle of placement and relatedness of the various accipitrine hawks ("accipiters" and harriers; nearly all formerly in Accipiter and Circus), the genus Accipiter lost about 80% of the species formerly assigned to it, leaving only nine current and extant species, with only two in the New World, depending on your taxonomic beliefs where Sharp-shinned Hawk is concerned. The species is highly polytypic, as currently arranged, with six various subspecies or groups of subspecies of surprisingly different-looking taxa scattered from Alaska and Canada south through the Caribbean and Mexico through Middle America to southern South America. In eBird parlance, these are:
➤ Sharp-shinned Hawk (Northern)
➤ Sharp-shinned Hawk (Caribbean)
➤ Sharp-shinned Hawk (Madrean -- no photos available at eBird)
➤ Sharp-shinned Hawk (White-breasted)
➤ Sharp-shinned Hawk (Plain-breasted), which has a black morph
➤ Sharp-shinned Hawk (Rufous-thighed)
I have provided this delineation of Sharp-shinned Hawk subspecies because Northern Sharp-shinned Hawks winter south into northern Colombia, and Cooper's Hawk regularly winters south through Costa Rica to Panama.
The final bit of this long preamble concerns sexual size dimorphism, a feature most strongly represented in ABA raptors in accipitrine hawks. Pyle (2008) listed various size measurements of the species considered here. Somewhat unfortunately, total length is not one of those. However, he was measuring specimens in museums, and the way individual specimens are prepared (e.g., the neck less or more extended) and how they dry create unknowable small changes in various body parts, making measurements of total length not particularly reliable for the individual bird or birds in question. Therefore, I must use the wing chord (distance between the wrist and the tip of the longest primary, measured on the folded wing, in millimeters) and tail length data (in mm) supplied.
Sharp-shinned Hawk: female (w) 188-214, (t) 197-235; male (W) 148-165, (t) 124-142
Cooper's Hawk: female (w) 244-283, (t) 197-235; male (w) 215-248, (t) 171-205
American Goshawk: female (w) 336-387, (t) 242-288; male (w) 302-346, (t) 207-250
As can be readily seen, there is no actual overlap in measures across species, some overlap within the sexes of American Goshawk, very little overlap (4 mm) in Cooper's Hawk, and zero overlap by sex in Sharp-shinned Hawk. While the sample sizes for all three species were only 100 birds measured of each sex, and there are certainly at least some individuals in all three species that are larger or smaller than indicated by Pyle's data, the actual spreads are probably only very little different from those presented. However, there is a fly in the ointment, as in my experience with many accipitrine hawks in the hand, juvenile accipitrine hawks have longer tails, size for size, than do their parents, and Pyle's data are not presented by age. Additionally, my birding experience suggests that juvenile female Cooper's Hawks have ridiculously longer tails, proportionately, than do any other age-sex class in those three species.
However, do note that Pyle's wing-chord data has just a single millimeter separating the largest female Sharp-shinned Hawk from the smallest male Cooper's Hawk. I will return to this.
Sharp-shinned Hawk is a small accipitrine hawk with a preference for relatively densely-treed habitats, particularly in the breeding season, and its relatively small size may be tied to the need to slalom through dense vegetation in pursuit of its generally small passerine prey. In contrast, Cooper's Hawk preys on larger items and, frequently, in much more open habitats, places in which straight-line speed may be more important than hyper maneuverability. Do not let the previous dissuade readers from the belief that Cooper's Hawks are not maneuverable. They certainly are, but on a larger scale, and that long, long tail of females, particularly juveniles, strongly suggests that agility, as the tail is the fulcrum against which birds turn when maneuvering.
Distinguishing between Sharp-shinned Hawk and Cooper's Hawk: Overall
As noted above, the Sharp-shinned Hawk is a smaller species than Cooper's Hawk. While the largest Sharp-shinned Hawks are not much smaller than the smallest Cooper's Hawks, correctly assessing the size of a single perched bird with little in the way of size reference to some other known-size object (avian or otherwise) is problematic; expectation bias may play a larger part than birders may realize.
tail graduation, r6 shape and graduation, ear coverts, crown color, crown/bill interface, mascara, eye proportion, hackles, underparts streaking (shape, extent, length), wingpits/side streaking/barring
Head structure
Sharp-shinned Hawk has a relatively small, relatively rounded head, on which a relatively large eye is roughly centered (as here). Cooper's Hawk has a relatively larger, blocky head on which a relatively small eye is placed well forward (as here). These two photos express nearly the maximal difference in head shapes and eye placement between the two species; some/many individuals are not quite so different, but these differences are useful in distinguishing virtually all individuals of both species.
Adult head color/pattern: Sharp-shinned Hawk -- The head pattern and coloration of adults of both species are grossly similar, but quite different in many particulars.
The overall color of the head is gray (medium to quite dark), orange, and white. Specifically, the forehead, crown, nape, and hindneck are gray with little or no contrast of tone or darkness throughout, and, for most individuals, that color does not contrast much or at all with the blue-gray color of the back (1, 2, 3, 4). Some individuals have the forehead, crown, and nape somewhat darker than the lowest portion of the hindneck and with somewhat sharp contrast (1, 2); I suspect these are males, but I know of no data set that treats such birds.
The "cheek" (comprised of all but the most distal ear coverts, as well as the lower feathers of the side of the neck) is orange (ranging from a paler peach to a darker, richer, almost rufous color) that contrasts strongly with the gray color of the most distal ear coverts (see peach link, above), crown, nape, and hindneck. The throat is white with orange streaking, varying across individuals from few, thin, and pale to many, thick, and dark (see peach and almost rufous links, above).
or whitish throat. but with darker orange/brownish streaks/lines laid over the orange face and
Distinguishing between Sharp-shinned Hawk and Cooper's Hawk: Perched
Head shape/eye placement/bill placement
Eye color
Underparts pattern, streaking extent and placement, cross bars, streaking color
Wing:tail
Tail tip
ML304105151 - Sharp-shinned Hawk - Macaulay Library - ad m
ML644959808 - Sharp-shinned Hawk - Macaulay Library - juv f
Distinguishing between Sharp-shinned Hawk and Cooper's Hawk: In flight, soaring
Distinguishing between Sharp-shinned Hawk and Cooper's Hawk: In flight, directional
ML436235631 - Sharp-shinned Hawk - Macaulay Library
Distinguishing among juveniles of Cooper's Hawk and American Goshawk
On a perched individual, and given a reasonably good view, four features are each quite useful in identifying these birds.
➤ All (or virtually all) of the individual greater coverts are without large, white or whitish polygons, such that there is no long, obvious wing bar (see the species-linked American Goshawk photo).
➤ The tail bands, alternating black and paler (gray or buffy-gray), are straight or gently curve in a very shallow arc across the tail from side to side.
➤ The dark tail bands are not bordered above and below by very thin white bands.
➤ The pale tips (the portion of the feather distal to the most distal dark band) of at least the central eight (varying among 8-12) rectrices (tail feathers) are the palest portion of the tail and are white in the vast majority of individuals; they are only rarely separated from the most distal dark band by gray or, very rarely, are entirely buffy and the same color (or very slightly paler) as the wide pale bands (photo 3)
