BIRDING BY HINDSIGHT: A Second Look at Hawks

I suppose it’s now politically correct to call them raptors. But then to be scientifically correct you’d have to go a step further and call them diurnal raptors to distinguish them from owls. For simplicity’s sake, let’s just call them hawks for now. (Or chicken-hawks, to be politically incorrect.) What we’re referring to those birds classified in the Order Falconiformes, even those things without the word “hawk” in their names: i.e., Osprey, kites, eagles, Northern Harrier, American Kestrel, Merlin, and falcons.

It would be nice if hawk identification were as easy as deciding what group name to use. But, as virtually every birder knows, hawks present some of the most difficult problems around, difficulties even experienced birders are often unable to solve. Hawks are typically seen at long distances or when just flying by, which makes it hard to study their plumages. And the plumages they have don’t usually amount to very much. Since predators partly rely on being inconspicuous to successfully hunt, they generally lack bold plumage patterns or distinctive colors.

Some hawks (eagles and buteos especially) vary considerably in their appearance within the species, even those of the same age or sex. We’re also told by seasoned hawk watchers to always consider a hawk’s shape and flight style when trying to identify it, but those features can change dramatically depending on whether that hawk is soaring, pursuing prey, gliding, diving, or flying with or against the wind.

Those all-purpose field guides we rely on are also of limited help. Their condensed and overly simplified species accounts often lead the unwary and inexperienced birder to as many misidentifications as correct ones. While you can’t entirely learn hawk identification from a book, I can at least recommend two specialized references by William Clark and Brian Wheeler which advance far beyond the standard field guides: A Field Guide to Hawks (part of the Peterson Field Guide Series by Houghton Mifflin, 1987; note that a second edition is pending) and A Photographic Guide to North American Raptors (Academic Press, 1995).

[Author's Note, July 2016 – Other raptor ID references have now been published, including A Field Guide to Hawks of North America (the second edition of A Field Guide to Hawks).]

This article is hardly intended to be a complete analysis of hawk identification problems. The bewildering assortment of Red-tailed Hawk plumages, for example, goes far beyond the scope of this Hindsight series of articles. And, even after 20 years as naturalist at Hawk Ridge Nature Reserve, I still hesitate to identify Cooper’s Hawks with any consistent certainty. Frank Nicoletti, Hawk Ridge’s resident hawk counter and ID expert, will readily vouch for this self-assessment!

Perhaps these more complex subjects will be the basis of future articles in this series, but for now I will simply introduce and briefly discuss some of the most frequent identification problems Minnesota birders seem to face. It can even take the form of a David Letterman-like Top Ten List: “Top Ten Reasons Why Hawks Are Misidentified”. Unlike Letterman, though, let’s begin with reason Number One:

1) Bald Eagles aren’t always bald.

While I’m sure such a fine and upstanding MOU member as yourself would never mistake an immature Bald Eagle for a Golden Eagle (or at least would never admit it), I suspect this is the most frequent hawk identification error of all. With so much interest on the part of so many who like to watch eagles, there are a lot of casual observers out there who understandably but erroneously assume that any eagle with out a white head and tail must be a Golden. Of course, it normally takes a Bald Eagle four years to attain its trademark plumage, and before then that relatively dark immature eagle faces three years of potential misidentifications by its adoring public.

But even more experienced hawk watchers can still make a similar mistake. The next time an immature Bald Eagle flies over, take a good look at its tail and don’t be surprised if it’s mostly whitish with a dark tip, just like an immature Golden Eagle. If a birder concentrates too much on this one field mark, chalk up yet another Bald Eagle mistaken for a Golden.

And speaking of immature Bald Eagles, be sure to read on as to how they end up being misidentified as Ospreys (#4) and even Swainson’s Hawks (#7).

2) Seen almost everywhere and identified as almost everything.

The hawk responsible for all this rampant confusion is the Red-tailed, and this is due in part to this species’ highly variable assortment of plumages which include features the field guides fail to mention. One thing which always confounds the novice hawk watcher is the immature’s lack of a red tail (it’s brown and barred). Another prevailing source of confusion is that Red-taileds of all ages (except dark-morph birds) have whitish upper tail coverts and are typically whitish as well on the base of their tails; and many paler Red-taileds of the Great Plains have tails which look more white than red. Since the field guides say little or nothing about this, hawk watchers often think they’re seeing a Rough-legged, or Ferruginous, or even a Northern Harrier.

An immature Red-tailed has another feature which frequently misleads the unwary. Its wings have whitish panels or “windows”, and these lead to many erroneous reports of Ferruginous and Red-shouldered hawks. Note, however, these pale areas are rectangular or square in shape, aligned parallel to the body, and include both the inner primaries and primary coverts. The whitish patches on a Ferruginous are aligned perpendicular to the body along the base of the flight feathers, and they exclude the wing coverts. Those on a Red-shouldered are narrower crescent-shaped lines parallel to the body and limited to the outer primaries.

I could go on here to explain how the head-throat-chest patterns of Red-taileds, Rough-leggeds (see #6), and Swainson’s (#7) get mixed up as well. But let’s just say for now if you see a funny-looking buteo and you’re not sure what it is, call it a Red-tailed and you’ll usually be right.

3) They have a lot in common with Whooping Cranes.

It happens all the time with Snow Geese and pelicans and even paler-looking Sandhill Cranes. They just don’t get all the press coverage enjoyed by those endangered Whooping Cranes, and, as a result, overly optimistic observers often engage in too much wishful thinking and report them as Whoopers. Similarly, the endangered Peregrine Falcon gets so much attention that when an unfamiliar hawk is encountered by someone, it’s again only natural for wishful thinking to take over. The result: almost any hawk can and does get reported as a Peregrine. (And if all those Peregrine reports were true, it would hardly rank as an endangered species any more.)

Probably the hawk most frequently mistaken for a peregrine would be the Merlin, which is also a dark falcon with “whisker” marks or “sideburns”. But I have also seen immature Broad-winged Hawks miscalled Peregrines due to their similar size, dark malar areas, and frequently pointed-wing profiles (see #5). And the face patterns of some Gyrfalcons (especially gray-morph immatures) with their dark and quite noticeable malar marks are also strongly reminiscent of Peregrines.

Conversely, real Peregrines can be mistaken for other things. This is especially true of immature tundrius Peregrines, those relatively pale-headed birds from the Arctic which are most of the migrant Peregrines in Minnesota each fall.. They have narrow sideburns and pale superciliums, and the result is a strong potential for confusion with a Prairie Falcon or a Gyr.

4) The winter of our discontent with Ospreys and Broad-wingeds.

And now, a shameless attempt to inject a bit of literary class into this TV-type Top-Ten treatise. If John Steinbeck had been a birder, one might guess the title of one of his best known works could be about misidentifying hawks in winter. Dismay may be a better word than discontent for it, but it is often downright disturbing how often Ospreys, Broad-winged Hawks, and even Swainson’s are reported here from November through March. At this time of year these three species are supposed to be in Central or South America, but this fact is not taken into account by some misidentification experts.

So, if they’re not Ospreys or Broad-wingeds or Swainson’s, what is really being seen out there? I suspect Bald Eagles or Rough-legged Hawks are the source of most of those Osprey reports. Subadult Bald Eagles can have a mostly whitish head with an Osprey-like line through the eyes. And a light-morph Rough-legged has a black “wrist” or carpal mark on the under wing which can be mistaken for a similar mark on an Osprey. But note, despite what some field guides show, the black on an Osprey’s under wing is not limited to the carpal area.

As for those winter Broad-winged reports, I assume that other hawks with dark and light tail bands are what birders are really seeing: i.e., Red-shouldereds or Cooper’s or one of the other accipiters (see #8). And what about those erroneous Swainson’s reports? I suspect what is really being seen are adult male Rough-legged Hawks (#6), Red-taileds, or even immature Bald Eagles (#7).

5) Hawks are often trying to make a point.

“Look at the hawk’s shape,” is what all those self-righteous and self-appointed experts (myself included!) keep reminding all those watchers struggling with hawk identification. But that’s easier said than done, partly because an essential part of a hawk’s shape is its wing tips. Although they’re supposed to pointed on falcons and rounded on just about everything else, it doesn’t always work out that way.

The rounded wing tips of any hawk can look pointed if, for example, that hawk is flying into the wind. As a result, I have frequently seen accipiters and buteos mistaken for falcons: e.g., immature Broad-wingeds (see #3) and adult Northern Goshawks with their dark cheek patches are miscalled as Peregrines; and goshawks of any age have a long history of being mistaken for Gyrfalcons.

Another surprising source of confusion are Northern Harriers, especially females and immatures which show dusky patches at the base of their under wings. Take one high-flying harrier (and they often fly at unexpectedly high altitudes in migration), turn it into the wind to give its wing tips a pointed aspect, add in a glimpse of its dark under wings, and you have the recipe for one erroneous Prairie Falcon sighting.

Finally, a couple other comments on falcons, those hawks which are supposed to have truly pointed wing tips. First, take some good looks at American Kestrels flying by and you’ll quickly come to realize how often their wing tips actually look more rounded than pointed (which often serves to separate them from Merlins). And, second, note that the larger falcons (Prairie, Peregrine, and Gyrfalcon) often circle around overhead while hunting or migrating – and when not in a hurry, these hawks can appear to have wing tips which look quite rounded.

6) Adult males aren’t always in the field guide.

As every field guide reader knows, the first (and sometimes only) things pictured are adult males. Whether it’s a duck, bluebird, warbler, tanager, cardinal, oriole, or finch, the generally more colorful plumages of those adult males are what sells books and are what people want to look at. With many birds, of course, there is little or no difference between the sexes or ages, but it is curious that for a long time one adult male never has been portrayed in the field guides: the Rough-legged Hawk! The Geographic guide sort of has an illustration of one (but not really), and, of course, Clark and Wheeler’s two references mentioned earlier show it. But even now about all the books actually show us is an immature Rough-legged.

Naturally, when an adult male Rough-legged flies into view (and for the moment let’s just talk about light-morph birds), it can’t help but cause confusion. Its tail is multi-banded, not clean-cut as on a female or immature with a white base and black band. It also lacks the oft-illustrated body pattern of the female/immature: i.e., buffy head and chest sharply contrasting with a solid black belly. Instead, adult males (and some adult females) are more variable, with a darkly streaked throat/upper breast area, a streaked belly, and a lighter area in between. The result is that many an adult male Rough-legged has been mistaken for a Red-tailed Hawk or a Swainson’s.

Two final comments on Rough-legged Hawks. First, on several occasions I have seen birders watch a hawk hover over its intended prey and assume they were looking at a Rough-legged. The truth is almost any species of hawk can hover. Second, any discussion of the more difficult issue of dark-morph Rough-leggeds (and other buteos) will have to wait. For one thing, there isn’t enough space here, and, for another, my knowledge of dark-morph Rough-leggeds ranks right up there with my expertise on Cooper’s Hawks!

7) You might look strange too if you ate grasshoppers.

The strange-looking, insect-eating hawk I refer to here is the Swainson’s Hawk. While the identification of adult light-morph birds is pretty straightforward, and dark-morphs don’t occur often enough in Minnesota to be a frequent problem, those first- and second-year immatures can look especially odd. At that age the Swainson’s diagnostic under wing pattern is more obscure, and its head and body are boldly and variably marked with dark brown spots and patches. The darkest markings are typically on the sides of the neck, suggesting the beginnings of this species’ trademark chest band.

Actually, this chest band on a Swainson’s is not nearly as useful a mark as is its diagnostic under wing pattern of dark flight feathers contrasting with whitish wing linings. Birders who rely too much on looking at throat/breast bands, as previously mentioned, can misidentify adult male Rough-leggeds as Swainson’s. Red-taileds as well get confused with Swainson’s all the time as a result of their dark neck/throat areas which suggest a Swainson’s-like chest band. And, despite their superior size, many immature Bald Eagles are another source of confusion. Not only can they have a dark chest, but they also show an under wing pattern reminiscent of a Swainson’s.

A Swainson’s Hawk also confuses many because of its small but well defined white patch on the upper tail coverts. Since most birders are unaware of this, confusion with Northern Harrier results. Finally, be aware of one useful mark to look for on a perched Swainson’s. Its folded wing tips reach – or even extend a bit beyond – the end of the tail, unlike other Minnesota buteos. (Although note that the wing tips on perched immature Rough-leggeds can almost reach the end of their tails.)

8) Band width problems aren’t only on the internet.

I’m told there are band width problems on the internet, but I have no idea what that means. Unless, that is, it’s birders discussing by e-mail the problems they’re having with tail band widths as they identify hawks. It seems those pesky field guides are at it again, failing to show the way things really are. We are led to believe, for example, that accipiters and adults Broad-winged Hawks have dark and light tail bands of equal width, and that the light tail bands on Red-shouldereds are narrower than the dark ones.

In reality, however, the dark tail bands on all three accipiters are actually narrower than the light bands, with this feature especially evident on the under side of the tails. Conversely, the one visible white tail band on an adult Broad-winged Hawk is actually a bit narrower than the two visible black bands. And be aware that, despite what the pictures in the books show, only three tail bands (two black, one white) are usually visible on a flying adult Broad-winged. Adding to the confusion are some Red-shouldereds whose dark and light tail bands can appear to be about the same width. The result of all this: Red-shouldereds mistaken for Broad-wingeds and vice versa.

And while we’re on the subject, keep in mind that the tail banding on an immature Broad-winged is indistinct and unlike that of an adult. Remember as well, as mentioned earlier in this article, that adult light-morph Rough-legged Hawks have multi-banded tails. Even more confusing are adult dark-morph male Rough-leggeds: they actually have tail banding quite similar to that on a Red-shouldered!

9) Some windows could even confuse Bill Gates.

The previous section was about band widths, this one is about windows, and neither one has a thing to do with computers. The “windows” under discussion here refer to the pale panels or translucent patches on the wings of some hawks. (And these can be just as confusing to hawk watchers as Bill’s Windows are to hapless computer users!)

Reason #2 above discussed how immature Red-taileds often become mistaken for Ferruginous or Red-shouldered hawks due to their windows. An immature Broad-winged Hawk, by the way, has windows much like those on a Red-tailed: i.e., pale rectangles on the inner primaries and primary coverts aligned parallel to the body. Note as well that immature and some adult Rough-legged Hawks have windows on their outer primaries: somewhat like those on a Ferruginous Hawks, although smaller.

Interestingly enough, I have also seen accipiters with translucent wing windows. It has only been in recent years that I became aware of how a backlit accipiter often shows windows when viewed from below. They tend to be narrow, aligned parallel to the body, limited to the outer primaries, and consequently are a possible source of confusion with Red-shouldered Hawk.

10) They’re no longer hawks, but they’re still misidentified.

Don’t get too attached to your favorite field checklist since some recent changes are affecting the way it will look. Those hook-billed shrikes and vireos, for example, now appear earlier on that list, right after the flycatchers. And Minnesota hawk watchers will find one less Falconiformes species to deal with, as the Turkey (and Black) Vulture has been promoted to appear in a separate family.

I expect, however, that hawk watchers will still watch and count vultures, and continue to include them in their misidentifications. Probably the most frequent problems involve Turkey Vultures, dark-morph buteos (especially Rough-legged Hawks), and adult Golden Eagles, since these are all blackish overall with contrastingly paler flight feathers on the underwing. It is amazing, for example, how vulture-like a Golden Eagle can appear due to its relatively small head (compared to a Bald Eagle) and the frequent dihedral aspect of its wing profile.

By the way, even though there are few Black Vulture records for Minnesota, if you think you’ve found one be sure to keep two things in mind. First, at certain angles a Turkey Vulture’s outer primaries when seen from above can look paler than the rest of the wing and thus suggest the pattern of a Black Vulture. And, second, the next time you are Down South and see a Black Vulture, don’t be surprised if it glides with a dihedral: despite what almost all the guides say, Black Vultures do this all the time. The flight difference between the two vultures is not in their glide but in their flapping: slow and labored in the Turkey Vulture, quicker and snappier in the Black.

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Now that August and the early signs of fall migration are upon us, this would be as good a time as any to start working on your hawk identification skills. With so many raptors — diurnal and nocturnal alike — heading south in the coming weeks past Hawk Ridge in Duluth, there will be plenty of opportunities to make use of the identification hints mentioned above. And if you see me there and have any more questions, just ask. About anything — well, almost anything. If it’s about Cooper’s Hawks, better talk to Frank.